D

RESULTS AND

DISCUSSION

142

4. RESULTS AND DISCUSSION

India is experiencing an epidemic of type 2 diabetes mellitus and cardiovascular

diseases, attributed to epidemiological and nutrition transition occurring in urban

and rural areas though at faster levels in urban settings. Nutrition transition is

marked by a change in the food supplies and consumption, especially the shift

from traditional Indian home-cooked foods to more processed foods which are

rich in sugar and fats – particularly trans fatty acids. Recent evidence shows that

specific fatty acids affect cell metabolism, modifying the balance between fatty

acid oxidation and lipogenesis.

There is a significant and growing body of evidence linking trans fatty acids to

coronary heart diseases indicating TFA may do even more harm than saturated

fats. Metabolic studies, for instance, show that trans fatty acids increase blood

levels of LDL cholesterol and decrease blood levels of HDL cholesterol. Both

effects are strongly associated with increased coronary heart diseases. Saturated

fats are thought to be less damaging because they elevate both the “bad” and

“good” types of cholesterol. Epidemiological data also point to a greater risk of

coronary heart diseases from increases in dietary TFA than from increases in

dietary saturated fats. Further, apart from cardiovascular diseases, studies also

indicate that TFA consumption has been positively associated with ovulatory

infertility, complications during pregnancy, cognitive decline, certain types of

cancers, asthma and allergies as well as adverse effects on foetal and infant

development.

In view of these adverse effects of trans fatty acids on human health, governments

in the developed countries have taken stringent actions by adopting strict policies

to curb trans fats from the food supply. However, in India not much work has

been done in this regard; therefore, the present study has been carried out to

estimate the TFA content of fats/ oils, study the formation of TFA in re-heated

oils as well as analyzing the TFA content of some fried/ baked food items and

dairy products commonly consumed in Indian households. Using the laboratory

143

analyzed values of TFA, the study further aimed to assess the dietary intake of

TFA by women belonging to middle/ upper middle income group (MIG/ UMIG)

families from Delhi and study the effect of TFA on anthropometric measurements,

body composition, clinical and biochemical parameters. The present study has two

components field work and the laboratory analysis. The result of the preliminary

data from field work served as the basis for initiating and carrying out the

laboratory analysis. While the result outcomes of laboratory analysis helped in

understanding the adverse effects of TFA on the health status of the population

under study. Thus, the two components of the study, field work and laboratory

analysis complemented each other and helped in arriving at the study results and

conclusions. The study was approved by human ethics committees of Institute of

Home Economics and Fortis hospital Vasant Kunj, New Delhi.

The field work comprised of gathering the preliminary data on commonly

consumed fats/ oils, deep fat frying practices and knowledge regarding TFA as

well as assessing the TFA intake by women belonging to MIG/ UMIG families.

For this, 402 female school teachers were enrolled from six schools located in

different parts of Delhi and the necessary permission was obtained from the

school authorities. After obtaining written informed consent, data were gathered

on their socio demographic profile, medical history, dietary intake, anthropometric

measurements, body composition, clinical and biochemical parameters. An

attempt has been made to study the effect of TFA intake of the subjects with their

anthropometric measurements, body composition, clinical and biochemical

parameters.

In addition a small preliminary survey was also carried out among chefs/ cooks of

select food outlets from Delhi/ NCR, where the necessary data pertaining to their

frying practices/ type of oil used and awareness regarding TFA were gathered.

The laboratory analysis involved estimating the TFA content of fats/ oils, as well

as studying the formation of TFA in fats/ oils subjected to varying temperatures

with or without frying the food items. Further the study also included analysis of

144

the TFA content of certain fried/ baked food items and dairy products commonly

consumed in Indian households. For the purpose of heating edible fats/ oils, due

permission was obtained from the Institute of Home Economics (University of

Delhi), Hauz Khas New Delhi to avail of the facilities available at the Food

Science laboratory. After obtaining the necessary permission from the Foundation

for Innovation and Technology Transfer (FITR), Indian Institute of Technology

(IIT) Delhi, the quantitative analysis of Trans Fatty Acids (TFA) content of select

fats/ oils, fried/ baked food items and dairy products was carried out at the

Department of Chemical Engineering, Indian Institute of Technology (IIT) Delhi.

For clarity and better understanding of the study outcomes, the results are being

discussed as below:

Preliminary data from field work

− Data relating to school teachers

− Data gathered from cooks/ chefs working in restaurants/ fast

food joints/ road side vendors/ bakery shops

Laboratory analysis

− Fatty acid profile including TFA content of edible fats/ oils

− TFA content of select edible fats/ oils both before and after

heating/ frying at varying temperatures

− Fatty acid profile including TFA content of commonly

consumed fried/ baked/ dairy food items

Composite use of the Laboratory Analysis and Field Work Data

− Dietary Intake with Special reference to Trans fatty Acids

− Anthropometry, body composition, clinical and biochemical

parameters

− TFA intake vis cardio-metabolic risk factors

4.I FIELD SURVEY; PRELIMINARY DATA

For this purpose 400 female school teachers were proposed to be enrolled from

schools located in different parts of Delhi. After obtaining necessary permissions,

initially five schools were approached; however, in order to have the necessary

145

sample size (n = 400), one more school was approached. 417 teachers were found

to be eligible for participation in the study. Out of these 417 teachers, only 406

provided their consent. Although 406 teachers were enrolled in the study, the

dietary data could not be gathered from four of them, as two teachers got

transferred to other schools, one went on maternity leave and one had left the job

due to some personal reason. Thus, the total sample comprised of 402 school

teachers. For the biochemical parameters, it was proposed to collect the blood

samples from one-third of the enrolled subjects (n=135) from 2 schools. However,

the targeted number could not be achieved, therefore one more school (from the

six schools selected) was approached for blood samples. Thus, the final sample

size for biochemical parameters’ estimation is 162 subjects. Once the teacher

expressed her interest in participating in the study and provided consent, the

preliminary survey questionnaire cum interview schedule was administered. The

details of this questionnaire cum interview schedule included socio demographic

profile and required the subjects to mark the commonly consumed fats/ oils/ fried/

baked/ dairy and other food items and deep fat frying practices adopted at home.

The commonly consumed fats/ oils and food items were then identified from the

choices marked by the subjects in their preliminary questionnaire. These were the

basis for carrying out the laboratory analysis and were then analysed for their fatty

acid profile (saturated, unsaturated and trans fatty acids) at the department of

Chemical Engineering Indian Institute of Technology, Delhi.

4.I.1 SOCIO DEMOGRAPHIC PROFILE

Age, Marital Status and Religion: Of the total 402 subjects enrolled,

nearly half (52%) were in the age range of 35 to less than 45 years (mean

age 41.6 ± 8.6 yrs.). A little more than one-fourth of the total subjects

(26.7%) were aged between 27 to less than 35 years and 21.3 per cent aged

between 45 to 60 years (Table 4.I.1). Majority of the subjects were Hindu

(76.8%) followed by Sikhs (12.7%), Muslims (6.7%) and Christians

(3.7%). Further, majority of the subjects were married (85.6%) while

remaining were either unmarried (11.2%), separated (~1%) or widowed

(2.2%).

146

Educational Qualifications: Since all the subjects under study were

female school teachers, their educational status was quite high. Detailed

survey regarding the educational qualifications among the subjects

revealed that all the subjects were at least graduates with bachelors in

education (B. Ed) which is a mandatory qualification for teachers. 40 per

cent were post-graduates, almost 7.2 per cent of the total subjects had

double post-graduation, while around 4 per cent possessed Ph D degree.

Family type and family size: On the basis of size or structure and the

depth of generations, family can be classified into three main types; (i)

Nuclear or the single unit family, (ii) Joint family and (iii) extended

family. Nearly three-fourth of the subjects (78.6%) were from nuclear

families while remaining were either from joint families (19.9%) or from

extended families (n=6; 1.5%). The total number of family members

ranged between 2 - 10 members with average family size being 4.1 ± 1.8

members in a family. The average number of adults per family was 2.6 ±

1.2 ranging between 1 to 8 members, while the average number of children

(<18 years) per family was 1.4 ± 0.89 ranging between 0 to 3 children.

Income and Socioeconomic Status: The average monthly income of the

subjects was ` 39,838.3ranging between ` 28,000 to ` 55,000, with

majority of the subjects (73.1%) earning between ` 35000 - ` 45000.

While the average monthly income of the family was ` 94, 4450 (` 60,000

to ` 1,65,000).

4.I.2 DIET RELATED DATA

Some amount of information was also gathered from the subjects regarding

cooking practices. These included type and amount of fat used, fried food items

prepared, consumption of fried/ baked and dairy foods and deep fat frying

practices adopted (amount of fat/ oil taken for frying, duration of heating fat/ oil

147

before frying/ its re-use and storage of oil after frying etc.). This information

played as the foundation for the laboratory analysis component of the study.

4.I.2.1 Cooking Practices and Commonly Consumed Fats/ Oils

Data gathered indicate that the subjects were consuming varied type of fats and

oils. It was noted that in general three or more fats/ oils were being used by most

of the subjects for the purpose of cooking (sautéing and baghaar), frying,

shortening, baking and as sandwich spread. Traditional usage, cost and even

“Health Claims” were the major determinants while making the choices regarding

type and brand of the cooking/ frying medium.

Subjects reported the use of a variety of fats/ oils, with all of them consuming

mustard oil of different brands like Panghat, Kachhi ghani, Kannodia etc. mainly

for preparation of specific vegetables. Groundnut oil was consumed by 14.7 per

cent of the subjects both for the purpose of cooking as well as frying; the major

brand being Fortune and Dhara.

Further, it was seen that soybean oil was consumed by 30.5 per cent of the

subjects; the commonly used brands included Fortune, Nature fresh, Dhara etc.,

while 15.9 per cent were using sunflower oil (Nature fresh, Fortune, Sundrop

etc.). A little more than one-fourth of the subjects (26.9%) were also using refined

blended oils with major brands being Saffola Gold, Sundrop Heart and Saffola

Tasty. Use of Olive and Canola was also seen in 24.1 per cent and 7.7 per cent of

the subjects respectively. Olive oil was also reportedly being used for baking by

4.7 per cent subjects. Desi ghee was being used by all the subjects mainly for the

purpose of baghaar, however, some even used it for frying (~4%) and shortening

(62%). Rice bran oil (~4%), Palmolein oil (1.7%) and coconut oil (~1%) were

reportedly being consumed by only a small percentage of the subjects.

148

Table 4.I.1: Distribution of the subjects by their socio-demographic profile

Surprisingly Vanaspati was, also being consumed by 7.2 per cent of the subjects

mainly for the purpose of frying, however some even used it for cooking

Particulars N (%) Particulars N (%)

Age Average Family Size 4.2 ± 1.3

Average Age 41.6 ± 8.6 ≤3 114 (28.4)

<35 years 107 (26.7) 4-5 254 (63.2)

35 - <45 years 209 (52.0) 6-7 28 (7.0)

45 - 60 years 86 (21.3) ≥ 8 6 (1.6)

Educational Qualifications

Marital Status Graduation (BA/ B.Sc.) + B. Ed

(Basic qualification) 402 (100)

Married 344 (85.6) Post-Graduation (MA/ M.Sc.) + B. Ed. 161 (40.0)

Unmarried 45 (11.2) Double Post-Graduation + B. Ed. 29 (7.2)

Divorcee/

Separated 9 (2.2) Ph D 16 (4.0)

Widowed 4 (1.0) Socio Economic status

MIG 207 (51.5)

Religion UMIG 195 (48.5)

Hindu 309 (76.9) Subject’s Monthly Income

Christian 15 (3.7) ` 25000 - <` 35000 42 (10.5)

Muslim 27 (6.7) ` 35000 - <` 45000 294 (73.1)

Sikh 51 (12.7) ` 45000 - <` 55000 56 (13.9)

≥ ` Rs 55000 10 (2.5)

Type of Family Monthly Income of the Family

Nuclear 316 (78.6) ` Rs 50000 - <` 75000 28 (7.0)

Joint 80 (19.9) ` Rs 75000 - <` 100000 237 (58.9)

Extended 6 (1.5)

≥ ` Rs 100000 137 (34.1)

149

purposes (1.5%); the brands included Rath, Dalda, Panghat and Gagan. This

clearly indicates that Vanaspati the so called “Bad fat” is still being consumed by

the population at large, even in the middle and upper middle income groups, who

have proper formal education and assess to all kinds of nutritional and health

related information.

Figure 4.I.1: Distribution of subjects based on reported use of fats/ oils

Among the other fats being used, 89.3 per cent subjects reported the use of

yellow pasteurized butter as bread spread, or for the purpose of shallow frying

(16.9%) and even baking (20.1%), the major brands were Amul and Britannia.

Around 27.1 per cent subjects also reported the use of White butter (either

homemade or purchased from local bakery). Interestingly Peanut butter (~7%)

and vegetable oil based sandwich spread (21.8%) were also being used by the

subjects, as they considered it as a “healthy replacement” for butter.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Per cen

t (

%)

150

Table 4.I.2: Reportedly used fats/ oils for various culinary practices

(Multiple Responses)

Commonly

Used Fats/

Oils

Reported

Usage

Culinary Practices (%)

N % Cooki

ng

Fryin

g

Shorteni

ng

Bakin

g

As

Spread

on /

Bread/ chapati/

parantha

Mustard oil 402 100.0 100 -- -- -- --

Groundnut oil 59 14.7 14.7 14.7 3.5 -- --

Soybean oil 123 30.5 30.5 30.5 -- -- --

Sunflower oil 64 15.9 15.9 15.9 -- -- --

Olive oil 97 24.1 24.1 2.2 -- 4.7 --

Canola oil 31 7.7 7.7 0.9 -- -- --

Blended oil 108 26.9 26.9 26.9 -- -- --

Rice bran oil 16 4.0 4.0 2.2 -- -- --

Palmolein oil 7 1.7 1.7 -- 1.7 -- --

Coconut oil 4 1.0 1.0 -- -- -- --

Vanaspati 27 7.2 7.2 3.5 7.2 -- --

Desi ghee 402 100.0 100.0 24.3 24.3 -- 46.7

White Butter 109 27.1 -- -- -- -- 27.1

Yellow Butter 359 89.3 16.9 -- -- 20.2 89.3

Peanut Butter 28 7.0 -- -- -- -- 7.0

Veg. oil based

Sandwich

Spread

88 21.8 -- -- -- -- 21.8

4.I.2.2 Dietary Practices and Meal Pattern

Data were gathered from the subjects regarding food habits, meal pattern

consumption of outside food and dietary intake. This helped in understanding the

type and frequency of food being consumed, in particular high fat foods (fried/

baked) for calculating their nutrient intake. In the present study a two day 24 hour

dietary recall (one working and one non-working day) were conducted to obtain

the dietary intake data of the subjects. In addition, frequency of consumption of

various fried/ baked and dairy food items was assessed using a qualitative food

frequency questionnaire (FFQ). A FFQ helps to give quick and reliable

151

information on the habitual food intake and is often employed as a cross-

validation technique along with 24-hour dietary recalls to enhance quality of the

dietary data.

In the present study the frequency for consumption of fried/ baked and dairy food

items being consumed was categorised as daily, two-three times a week, once a

week, once in 15 days, once a month or occasionally/ very rarely (Annexure V).

Food Habits play an important role in prevention as well as management

of lifestyle diseases. Improper food habits can further contribute towards

development of lifestyle related non communicable diseases (NCD). In the present

study it was noted that most of the subjects surveyed were vegetarians (n=213;

53.0%) while the remaining were either eggitarians (n=92; 22.9%) or non-

vegetarians (n=97; 24.1%). Being an all women study it was expected that larger

number of the study subjects would be vegetarians as in India more number of

women are observed to be vegetarians due to either social or religious reasons in

comparison to men. Epidemiological studies indicate that an appropriately

planned, well balanced vegetarian diet offers several health benefits including a

lower prevalence of lifestyle related diseases in vegetarians as compared to non-

vegetarians. Compared to non-vegetarian diets, vegetarian diets which are low in

saturated fats, cholesterol, high in dietary fibre and contain adequate amounts of

proteins and vitamins can provide several health benefits and offer protective

effects (Deriemaeker et al, 2011). However, as a result of westernisation of the

Indian diets, even the vegetarian diets these days are rich in fat and refined

carbohydrate and low in protein. This rather than having any health benefit/

protective effect could further lead to lifestyle related diseases or aggravate the

condition.

Meal pattern: Nearly half of the subjects (49.5%) were consuming either

three main meals/ day (breakfast, lunch and dinner), while around one-fourth of

them were consuming two (28.9 %; lunch and dinner) main meals and four main

meals (21.6% breakfast, mid-morning, lunch and dinner) per day respectively. The

pattern of consumption of mid-meals/ snacks was also gathered from the subjects

152

and it revealed that nearly 50 per cent of the subjects were having two mid-meals/

snacks per day (early morning tea and evening tea), while 28.4 per cent subjects

were consuming three mid-meals/ snacks (early morning tea, mid-day tea and

evening tea). Others (17.7%) were consuming ≥4 number of mid-meals/ snacks

with a very few (3.5%) consuming 1 mid-meal/ snack in a day (Table 4.I.3). It is

always advised to have three balanced major meals and two or three light mid-

meals/ snacks containing healthy options as it elevates the metabolism and

provides continuous energy to the body, moreover people consuming five to six

meals a day (3 major meals and 2-3 mid-meals/ snacks) feel less hungry and do

not overeat (Misra et al, 2011). However, with large number of mid-meals/

snacks mainly consisting of high fat/ carbohydrate foods coupled with sedentary

lifestyle is leading to increase in the prevalence of obesity and related disorders.

Frequency of eating out: With rapid urbanisation there is hardly any time left for

working mothers to prepare wholesome food for the family on the daily basis. As

a result outside food (fast food/ instant food) has crept into our daily diets leading

to nutrition transition. In an attempt to have a deeper insight on the consumption

pattern, data was gathered on outside food consumption practice. Outside food

was popular among majority of the subjects (99.5%) with only 2 (0.5%) subjects

restricting to only home cooked food. The reasons provided by the subjects for not

indulging in outside food were poor health of spouse and weak digestive system

respectively. Frequency of consuming outside food varied from daily (6.0%) to

once a month (1.0%). Approximately one-fourth of the subjects (25.4%) reported

the consumption of outside food to be thrice a week, while 17.7 per cent reported

the consumption to be once a fortnight with majority of the subjects consuming

the outside food at least once a week (34.3%).

153

Table 4.I.3 Distribution of subjects by their Dietary habits meal pattern and

Frequency of eating out

Particulars N (%) Particulars N (%)

Dietary Habits Consumption of outside

food

Vegetarian 213 (53.1) Yes 400 (99.5)

Eggetarian 92 (22.9) No 2 (0.5)

Non-vegetarian 97 (24.1) Frequency of outside food

consumption

Meal Pattern Daily 24 (6.0)

No. of main

meals/day

3 times a week 102 (25.4)

2 116 (28.9) Twice a week 61 (15.2)

3 199 (49.5) Once a week 138 (34.3)

4 87 (21.6) Once a fortnight 71 (17.7)

No. of snacks/mid

meals/ day

Once a month 4 (1.0)

1 14 (3.5) Type of eating outlet

commonly visited

2 203 (50.5) Restaurants 77 (19.2)

3 114 (28.4) Indian Fast food joint/Halwai 152 (37.8)

≥ 4 71 (17.7) Western fast Food Joint 124 (30.8)

Road side vendor 49 (12.2)

Regular consumption of outside food, which is often high in simple carbohydrates

and fats, in particular trans fats, if prepared in re-used oil or coming through

vanaspati, is one of the prime reasons for the sudden increase in the load of

lifestyle related non communicable diseases in India (Misra et al, 2009a). Among

the eating facilities commonly visited both, Indian fast food joints/ halwai’s and

the western fast food joints were the most favoured ones (28.7% and 28.0%

respectively), but still the nearby roadside vendors were preferred (12.2%) for day

to day eating out/ snacking specifically for gol gappa and papri chaat.

Commonly consumed fried/ baked and dairy foods

Data regarding commonly consumed fried/ baked and dairy food items

were also gathered from the subjects. This data was crucial as it formed

154

the basis for laboratory component of the study in terms of the selection

of fried/ baked and dairy products for laboratory analysis for the fatty

acid profile including trans fatty acids.

Consumption of fried foods (prepared at home and or purchased):

Hectic work schedules, working couples, modernization of the lifestyle

have all contributed towards the concept of “eating out”, which has now

become an important social activity, at both personal as well as

professional level. This has been facilitated by the mushrooming of eating

outlets, in particular fast food joints offering wide range of food items in a

comparatively shorter time. It was found from the data that the subjects

were consuming a wide range of fried foods prepared at home as well as

purchased from the market.

Type of fried foods being consumed: Consumption of fried foods

containing high amounts of fats has been associated with obesity and

related disorders. The data depicted that the subjects were consuming a

wide variety of fried food items which included food items like Potato

Chips (85.3%), Pakora/ Kofta (81.3%), Kachori/ Mathri (86.8%),

Gulabjamun (72.4%), Jalebi/ Imarti (63.2%), Fried Aloo Chaat (84.6%),

Tikki (89.3%), Papri Chaat (74.4%) and Halwa (67.7%). Food items like

Nachos (45.0%), Cutlet (60.2%), Spring Roll (53.0%), Ladoo (51.7%)

were reportedly consumed by comparatively lesser number of subjects,

while more than 90% of them reported consuming foods like, Bread

Pakora (94.8), Vada (98.5%), Dosa/ Cheela (96.0%), Golgappe (99.5%),

Samosa (99.0%), Parantha (99.5%), French Fries (98.5%), Bhujiya

(93.5%), Bhatura/ Poori (91.3%) and Namkeen (99.5%). (Figure 4.I.2).

Frequency of consumption of fried foods: The frequency of

consumption of fried foods by the subjects varied. Food items like bhujiya,

namkeen and parantha were being consumed almost daily by a majority of

them, while ladoo, jalebi and gulabjamun were being consumed only

155

occasionally. Interestingly halwa was being consumed by 32 per cent

subjects on a weekly basis as part of their weekly religious fasts (Tuesday/

Thursday). Golgappe (Paani puri) was one of the most favoured food

items, reportedly being consumed by one-fourth of the subjects once in

every fifteen days, with 46.8 per cent subjects reported to consume it once

a month (Figure 4.I.3). One interesting observation was that food items

like samosa, bread pakora, kachori, gulabjamun etc were a common

feature in the school group parties, any retirement party or on the last

working day of each month.

4.I.2.3 Practices related to frying

Frying is a fast and convenient cooking technique widely used in industrial,

catering and domestic cooking processes. Despite its considerable fat content and

intensified awareness of the relationships between food, nutrition and health,

frying remains a principal cooking method and fried foods are consumed

worldwide with sustainable popularity as a result of their unique and delicious

sensory characteristics (Billek, 2000; Saguy and Dana, 2003).All the subjects

were doing some form of frying at home. The fat/ oil used for frying depended

upon the food item being prepared and the type of frying (shallow/ deep fat

frying) being done. For the purpose of deep fat frying, most of the subjects

(66.4%) were using different types of refined vegetable oils (groundnut; 14.7%,

soybean;30.5%, Sunflower; 15.9%, Olive; 2.2%, canola; 0.9% and rice bran;

2.2%), while around one-fourth of them (26.9%) were using blended refined

vegetable oils. 24.3 per cent subjects reported the use of desi ghee majorly for the

purpose of tempering (baghaar), preparation of parantha, toasting of bread on the

griddle and even for frying of specific foods gulabjamun etc. Surprisingly

vanaspati was also being used by 7.2 per cent of the subjects, basically to replace

desi ghee or for the preparation of mathri/ namakpara/ gulabjamun.

156

Figure 4.I.2: Distribution of subjects by the commonly consumed fried food

items

Quantity of fat used for frying: The total amount of fat/ oil being used

for frying depended on factors like, type and amount of food being fried,

number of servings to be prepared, quantity in each serving etc. For

gathering the information on amount of fat being used for frying,

approximate responses were obtained since measuring the oil prior to

putting it in the frying vessel was not practiced by the subjects. Of the

total 402 subjects enrolled, a little more than half of the subjects (53.7%)

were using approximately 350 - <500 ml of edible fat/ oil for frying at a

time, while 44.5 per cent reported use of 500 - < 750 ml. Interestingly 1.7

per cent subjects reported the use of 750 - < 1000ml of oil for frying,

however, these were the subjects staying in joint of extended families,

with large family size.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Per

cen

t (%

)

157

Table 4.I.4 Frequency of consumption of commonly consumed fried food

items

Fried Foods Daily

(%)

2-3

times a

week

(%)

Once a

week

(%)

Once in

15 days

(%)

Once

a

Month

(%)

Occasionally/

Very Rarely

(%)

Potato Chips 1.7 5.7 17.7 26.4 32.8 15.7

Bhujiya 44.5 22.9 6.2 3.5 14.2 8.7

Namkeen 35.3 25.6 14.4 10.7 8.5 5.5

Samosa 0.0 1.0 24.1 27.1 29.9 17.9

Bread Pakora 0.0 0.0 2.2 15.7 70.4 11.7

Pakora/ Kofta 0.0 0.0 15.4 43.3 16.7 24.6

Parantha 55.5 3.0 14.7 23.4 2.2 1.2

Bhatura/

Poori 0.0 0.0 11.9 26.4 32.6 29.1

Tikki 0.0 0.0 3.2 24.4 35.3 37.1

Fried Aloo

Chaat 0.0 0.0 1.5 30.3 24.1 44.0

French Fries 0.0 0.7 25.4 46.3 23.1 4.5

Papri Chaat 0.0 0.0 40.8 4.2 26.6 28.4

Gol Gappe 0.0 4.5 15.9 25.6 46.8 7.2

Cutlet 0.0 0.0 3.0 9.7 23.4 63.9

Spring Roll 0.0 0.0 1.0 2.2 20.6 76.1

Vada 0.0 0.5 17.2 29.1 30.8 22.4

Dosa/ Cheela 0.0 4.5 25.9 24.1 17.2 28.4

Nachos 0.0 0.0 0.0 3.2 10.9 85.8

Kachori/

Mathri 0.0 7.2 24.1 30.3 17.9 20.4

Gulabjamun 0.0 0.0 0.7 4.2 27.1 67.9

Jalebi/ Imarti 0.0 0.0 2.2 10.0 24.4 63.4

Ladoo 0.0 0.0 0.0 0.0 4.7 95.3

Halwa 0.0 0.0 32.1 4.2 3.5 60.2

158

Figure 4.1.3: Distribution of the subjects by the frequency of consumption of

fried food items

Duration of heating the fats/ oils before frying: The duration of heating

before frying depends on factors like the type of fried food to be prepared,

quantum of food to be fried, metal of the frying vessel and the heaviness of

the bottom of the frying vessel. Data regarding duration of heating fats/

oils of priorfrying was gathered to have an idea regarding deterioration of

the oil quality before actual frying is initiated. Further it was used for the

laboratory component of the study. Majority of the subjects were not able

to provide exact responses regarding duration of heating the oil prior to

frying thus approximate responses were obtained. Maximum number of

them (57.0%) reportedly allowed the oil to heat for approximately 10-15

minutes before initiating frying, while others reportedly heated the oil for

15-20 minutes prior to frying (Table 4.I.5). A very small percentage of

subjects (2.2%) reportedly heated the oil for as long as 20-30 minutes

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Gulabjamun

Jalebi/ Imarti

Ladoo

Halwa

Spring Roll

Vada

Dosa/ Cheela

Nachos

Kachori/ Mathri

French Fries

Papri Chaat

Gol Gappe

Cutlet

Fried Aloo Chaat

Samosa

Bread Pakora

Pakora/ Kofta

Parantha

Bhatura/ Poori

Tikki

Namkeen

Potato Chips

Bhujiya

Per cent distrbution of subjects

Co

mm

on

ly c

on

sum

ed

frie

d f

oo

d i

tem

s

Daily 2-3 times a week Once a week Once in 15 days Once a Month Occasionally/ Very Rarely

159

before initiating frying. This is quite a lot of time and definitely could not

be practiced unless large fat/ oil quantities are used for frying. Further, it

was noted that nearly half of the subjects (50.5%) initiated frying “when

the test food article added to hot fat/ oil quickly rises to the surface”, while

for another 45.3 per cent subjects the correct stage was when the oil started

smoking, however, few subjects (4.2%) reportedly initiated the frying

when the oil started smoking as well as smelling.

Reutilization of oil used for frying was done by a majority of subjects

(95.8%), while the remaining 4.2% either discarded the oil or gave it to

their domestic helps, as they felt that re-heating the oil is harmful for

health and thus should not be practiced. The used oil was mostly re-

utilised for the purpose of re-frying (69.9%) or for preparation of parantha

or vegetable preparation (25.9%). The most common practice of storing

used oil after frying was to allow it to stay in the same karahi in which the

frying was done (53.7%), while 40.3 per cent subjects stored in a separate

vessel, only a very small percentage of subjects (6.0%) were actually

filtering the used oil and storing it separately.

During frying, fats/ oils are subjected to various chemical reactions which

include oxidation, hydrolysis, isomerization, polymerization and

cyclization. As a result, a multitude of products are formed like free fatty

acids, trans fatty acids, mono and diacylglycerols, oxidized monomers,

dimers and polymers. Non-polar dimers and polymers as well as volatile

compounds are also produced (Moreno et al, 2007). At the high

temperatures of frying, thermal reactions occur, giving rise to cyclic

monomers, dimers and polymers. Highly deteriorated oil is referred to as

abused oil. Foods fried in abused fats /oils absorb these products, many of

which are potentially toxic on consumption (Mahungu et al, 1999).

Number of times the fats/ oils are re-used for frying: During frying, a

complex series of various chemical reactions takes place, including

160

thermoxidation, hydrolysis, polymerisation and fission resulting in

increased viscosity, darkening in colour, increased foaming and decrease

in the smoke point of the oil as frying continues. The rate of these

reactions depend on the compositions of the oil, the temperature and length

of frying, whether continuous or intermittent frying is done, the type of

food being fried and whether or not fresh oil is added to replenish the

frying oil (Fennema, 1996). In the present study data regarding re-frying of

the used oil was gathered to get an idea of the deterioration of the oil

occurring at household level. Further re-heating/ re-using the same oil has

been associated with increase in the formation of trans fatty acids.

With the approximate responses obtained from the subjects, the present

study demonstrated that reheating of fats/ oils for the purpose of frying

largely depended on the quantity of fats/ oils left after frying. Nearly one-

fourth of the subjects (27.6%) reportedly did not reheat the fats/ oils

because they either utilise the remaining fats/ oils largely for cooking

purposes (25.9%) or did not use it themselves (1.7%), another one-fourth

(24.4%) of the subjects reportedly reheated the oils once again to be later

used for cooking, while nearly half of them reportedly reused it at least 2-3

times (frying cycles). Further, a small percentage (4.7%) of the subjects

mentioned that they would keep using it till the quantity is reduced to be

used for sautéing vegetables in the same vessel (Table 4.I.5).

Addition of fresh fats/ oils to reheated fats/ oils during frying: Data

indicate that more than half of the subjects (73.4%) were adding fresh fats/

oils to the reheated fats/ oils for frying purpose, while 22.4 per cent did not

replenish the reheated fats/ oils with the fresh fat/ oil (Table 4.I.5). Studies

have indicated that the deterioration of the quality as well as production of

trans fatty acids in used oil lowers down with addition of fresh oil to the

used oil (Romero et al, 2000).

161

Table 4.I.5: Distribution of the subjects by their Cooking/ Frying Practices

Particulars N (%)

Approximate amount of fats/oils used for frying at a time

350 - <500 ml 216 (53.7)

500 - < 750 ml 179 (44.5)

750 - < 1000ml 7 (1.7)

Duration of heating oil before frying

10-15 minutes 229 (57.0)

15-20 minutes 164 (40.8)

20-30 minutes 9 (2.2)

Stage of oil at which frying is initiated

When the test food quickly rises to the oil surface 203 (50.5)

When oil starts smoking 182 (45.3)

When oil starts smoking and smelling 17 (4.2)

Re-utilisation of used oil for cooking purpose

Yes 385 (95.8)

No 17 (4.2)

Re-utilization of oils

Used for frying again 281 (69.9)

Used for sautéing/ preparation of vegetables/ making

parantha’s 104 (25.9)

Throw away or give to their domestic help 17 (4.2)

Storage of Used Oil

Allowed to remain in the same karahi 216 (53.7)

Store in a separate vessel 162 (40.3)

Filtered and stored in separate vessel 24 (6.0)

Number of times the fats/ oils are re-used for frying

Only once 98 (24.4)

2-3 times 174 (43.3)

keep using till the quantity is reduced to be used for sautéing 19 (4.7)

Used for sautéing/ preparation of vegetables/ making

parantha’s 104 (25.9)

Do not re-use 7 (1.7)

Addition of fresh oil to the used oil while frying

Yes 295 (73.4)

No 90 (22.4)

Do not re-use fat/ oil 17 (4.2)

162

Figure 4.I.4 Distribution of subjects by the commonly consumed baked food

items

Consumption of baked foods

Type of bakery products consumed: It was observed that a variety of bakery

products were being consumed by the subjects. Bakery products like bread and

biscuits were reportedly being consumed by all the subjects, however, white

bread (69.1%) was preferred over brown/ wheat bread (30.1%) as some of the

subjects did not like its taste. Cakes and pastry were also being consumed by

all the subjects. A majority of the subjects also reported the consumption of

rusks (78.8%) as their favourite morning tea accompaniment (Figure 4.I.4).

Burger (89.3%), Patties (71.1%), Pizza (78.6%) and cookies/ bakery biscuits

(75.9%) were also reported to be commonly consumed by a large number of

subjects. However, comparatively a smaller percentage of subjects reported

the consumption of bakery products like bun (30.8%), puffs (22.1%), Cream

Wafers (23.1), Muffins/ Brownie (26.6%). High consumption of baked food

replete with fats is also being viewed as a major contributory factor for

obesity, diabetes, heart diseases and related disorders.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Per c

en

t (%

)

163

Frequency of the consumption of bakery products: Baked food items,

such as rusks and biscuits were reportedly being consumed almost daily by

40 and 32 per cent of the subjects respectively, while food items like cake/

pastry were although being consumed by all, their frequency was reported

to be occasional by most of the subjects (77.6%). However, foods like

pizza were being consumed by nearly one-third of the subjects as part of

weekend eating out (Figure 4.I.5 and Table 4.I.6).

Table 4.I.6 Frequency of the consumption of bakery products

Baked

Food

Daily

(%)

2-3

times a

week

(%)

Once a

week

(%)

Once in

15 days

(%)

Once a

Month

(%)

Occasionally/

Very Rarely

(%)

White

Bread 18.2 10.4 19.7 6.5 15.2 30.1

Brown

Bread 16.4 12.2 1.5 0.0 0.0 69.9

Bun 0.0 3.5 9.0 3.2 5.5 78.9

Biscuits 32.1 26.1 25.4 12.7 3.0 0.7

Patties 0.0 1.0 1.5 9.7 26.9 60.9

Cakes/

Pastry 0.0 0.0 0.0 9.5 12.9 77.6

Puffs 0.0 0.0 1.5 4.7 6.0 87.8

Cookies/

Bakery

Biscuits 0.0 0.0 0.5 3.2 4.7 91.5

Cream

Wafers 0.0 0.0 0.0 0.0 0.0 100.0

Pizza 0.0 0.0 31.8 18.7 17.2 32.3

Burger 0.0 3.0 33.1 25.4 11.9 26.6

Rusk 40.5 4.5 1.5 3.2 23.4 26.9

Muffins/

brownie 0.0 0.0 2.2 1.7 4.7 91.3

Figure 4.I.5 Distribution of the subjects by the frequency of consumption of

baked food items

164

Figure 4.I.5 Distribution of the subjects by the frequency of consumption of

baked food items

Consumption of dairy products and other food items

- Type of dairy products and other food items consumed: The data

gathered depicted that dairy products were consumed by all the subjects in

one form or the other. Milk either full cream milk (48.3%), single toned

milk (28.4%) or double toned milk (23.4%) was being consumed by all the

subjects. Curds and cottage cheese were reportedly consumed by 98.8 per

cent and 100 per cent subjects respectively. Other dairy products being

consumed by the subjects included coffee (73.9%), cream (53.7%), cheese

slice/ spread (52.5%), khoa (25.6%), condensed milk (18.2%) and Rabri

(72.9%). Among the other food items being consumed, around 81.6 per

cent subjects reportedly consumed noodles, while chocolate was

reportedly being consumed by 93 per cent of the subjects. 52 per cent

subjects reported the consumption of vegetarian mayonnaise, while

mayonnaise with egg was being consumed by 23.9 per cent subjects

(Figure 4.I.6). A majority of the subjects also reported the consumption of

packet soups (71.4%).

0% 20% 40% 60% 80% 100%

White Bread

Brown Bread

Bun

Biscuits

Patty

Cakes/ Pastry

Puffs

Cookies/ Bakery Biscuits

Cream Wafers

Pizza

Burger

Rusk

Muffins/ brownieC

om

mo

nly

Co

nsu

med

ba

ked

fo

od

ite

ms

Daily 2-3 times a week Once a week Once in 15 days Once a Month Occasionally/ Very Rarely

165

Figure 4.I.6 Distribution of subjects by the commonly consumed dairy/ other

food items

- Frequency of consumption of dairy and other food items: Dairy

products like milk, either full cream/ single/ double toned milk, was being

consumed by most of the subjects on a daily basis, while others consumed

in 2-3 times a week. Tea, was consumed by all the subjects almost twice or

thrice in a day, however, consumption of coffee was reported by only 49.3

per cent subjects and that too either occasionally or very rarely. Curd was

also consumed 2-3 times a week by majority of the subjects, while dairy

products like khoa, rabri, condensed milk and cream were being consumed

only occasionally (Figure 4.I.7).

Among the other food items consumption of chocolates ranged from once

a week (24.1 %) to occasionally (36.3 %), while noodles were reportedly

being consumed once in 15 days by 29.3 per cent of the subjects (Table

4.1.7). Packet soups were also being consumed occasionally by majority of

the subjects (56.5%). A very small percentage of subjects reported daily

consumption of vegetarian mayonnaise (5.5%) and mayonnaise with egg

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Per c

en

t (%

)

166

(1.7%), with majority of them consuming it only occasionally or very

rarely (59.0 and 84.3 % respectively).

Table 4.I.7 Frequency of consumption of commonly consumed dairy and

other food items

Dairy & Other

Food Items

Daily

(%)

2-3

times a

week

(%)

Once

a week

(%)

Once

in 15

days

(%)

Once

a

Month

(%)

Occasionally/

Very Rarely

(%)

Milk Full Cream 20.6 26.4 1.2 0.0 0.0 51.7

Single Toned

Milk 24.4 4.0 0.0 0.0 0.0 71.6

Double Toned

Milk 22.9 0.5 0.0 0.0 0.0 76.6

Curds 14.2 48.0 24.6 11.9 0.0 1.2

Tea 98.5 0.0 0.0 0.0 0.0 1.5

Coffee 4.0 19.2 8.0 11.4 8.2 49.3

Cream 0.0 0.0 4.7 5.5 11.7 78.1

Cottage Cheese 0.0 14.7 41.5 28.4 9.5 6.0

Cheese Slice 3.5 17.2 20.9 4.7 2.7 51.0

Khoa 0.0 0.0 0.0 0.0 0.0 100.0

Condensed Milk 0.0 0.0 0.0 0.0 4.7 95.3

Rabri 0.0 0.0 0.0 0.0 11.7 88.3

Vegetarian

Mayonnaise 5.5 7.0 15.9 4.7 8.0 59.0

Mayonnaise with

Egg 1.7 1.5 3.0 4.2 5.2 84.3

Noodles 0.0 1.0 21.6 29.6 22.9 24.9

Chocolate 0.0 1.7 24.1 16.9 20.6 36.6

Packet soups 0.0 2.7 4.0 16.4 20.4 56.5

167

Figure 4.I.7 Distribution of the subjects by the frequency of consumption of

dairy products and other food items

4.I.3 Knowledge Relating to Trans Fatty Acids

In addition to the knowledge regarding trans fatty acids some preliminary data

were also gathered about their practices relating to re-heating of fats/ oils used for

frying as well as the awareness and practices relating to nutrition labelling (Table

4.I.8). Since the subjects under study were teachers who are aneducated and

cognisant section of the society, it was rather disheartening to know that about

one-third of the subjects (n=129) were aware of the fact that fats/ oils used for

frying should not he re-heated or repeatedly used. Amongst these 14.2 per cent

subjects considered that re-heated fats/ oils could adversely affect our health and

8.2 per cent subjects thought it to be bad for the heart while 9.7 per cent believed

that using repeatedly re-heated fats/ oils could raise the blood cholesterol levels

(Table 4.8).

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Vegetarian Mayonnaise

Mayonnaise with Egg

Noodles

Chocolate

Packet soups

Khoa

Condensed Milk

Rabri

Cream

Cheese Slice

Cottage Cheese

Cofee

Tea

Curds

Double Toned Milk

Single Toned Milk

Milk Full Cream

Per cent distribution of the subjects

Co

mm

on

ly c

on

sum

ed

da

iry

pro

du

cts

an

d o

ther f

oo

d i

tem

s

Daily 2-3 times a week Once a week Once in 15 days Once a Month Occasionally/ Very Rarely

168

When the subjects were asked which fat, out of the two, Desi ghee and Vanaspati

is better for our health, 65.4 per cent believed Desi ghee to be the obvious choice

however, surprisingly 4.2 per cent considered vanaspati as a better choice,

thinking that since it is made from vegetable oil it is less harmful. Further, 5.7 per

cent subjects had the view that both are equally good and 24.6 per cent subjects

reported that none of these is a good choice. Further, only 28.1 per cent subjects

had heard of the term trans fats/ Trans fatty acids/ TFA from different sources like

television/ magazine/ newspaper, but only 19.7 per cent could actually describe it

as a “Bad fat” while 5 per cent ended up describing it as a “Good fat”, the

remaining (71.9%) were simply ignorant about it. On being asked whether TFA is

good for health or not, 19.4 per cent answered in negative while remaining 80.6

per cent could not reply.

On being asked regarding the “Nutrition Labels” on the packaged food items, 52.7

per cent subjects reported that they always read the nutrition label before buying

the food product, and 28.4 per cent subjects reported that they checked the label

only “sometimes” while 18.9 per cent said that they did not read the nutrition

label, since they were sure of the quality in the brand or the reputation of the store

from which they were buying the food product. However, among these only 14.6

per cent subjects always remembered to check the TFA content on the “Nutrition

Label” while 11.7 per cent checked it “sometimes” and 73.6 per cent subjects

reported that they did not check the TFA content on the “Nutrition Label”.

The result of this small, yet effective, survey clearly shows the lack of knowledge

regarding trans fats and their adverse effects even among the educated class. Thus

the government as well as health care providers need to take a firm stand

regarding trans fats. Simply mentioning the TFA content on the nutrition label

will not solve the purpose, instead law should be enforced upon the manufacturers

to limit the content of TFA from the food supply and simultaneously consumer

needs to be made aware of the hazards associated with its consumption. We

should take a cue from this survey to plan an initiative to generate awareness

regarding good fats, bad fats and correct ways of using them including

169

disseminating information on healthy cooking practices among general

population.

Table 4.I.8 Knowledge on Re-heating of Fats/ oils and Trans Fats

Particulars N %

Aware of/ Heard of Not Re-heating Fats/ Oils

Yes 129 32.1

No 273 67.9

Aware of the adverse effects of Re-heating Fats/

Oils

It is Bad for health 57 14.2

Bad for heart 33 8.2

It can raise blood cholesterol 39 9.7

Don’t Know 273 67.9

Heard of the term “Trans Fats”/ TFA/ Trans fatty

acids

Yes 113 28.1

No 289 71.9

Knowledge regarding what are “Trans Fats”/ TFA/

Trans fatty acids

Good fat 23 5.7

Bad Fat 79 19.7

Don’t Know 300 74.6

Are TFA good for our health

Yes 0 0

No 78 19.4

Don’t Know 324 80.6

Between Desi Ghee and vanaspati which is a better

fat

Desi ghee 263 65.4

Vanaspati 17 4.2

Both are equally good 23 5.7

None of the two 99 24.6

Do you read “Nutrition Label” provided on the

packaged food item

Yes, always 212 52.7

Sometimes 114 28.4

No/ Do not get the time 76 18.9

Do you check the TFA value given on the “Nutrition

Label”

Yes, always 59 14.6

Sometimes 47 11.7

No/ Do not get the time 296 73.6

170

4.I.4 Preliminary Survey among Cooks/ Chefs

To study the fats/ oils used for food preparation and deep fat frying practices

adopted at commercial level, data has been gathered from 42 different commercial

food establishments randomly selected from Delhi/ NCR through a developed,

designed and pre-tested questionnaire, in order to elicit data on (i) General

information on food items being prepared, (ii) fats/oils being used, (iii)

equipments being used for food preparation, (iv) number of time the used oil is

heated, (v) re-use of fats/ oils and other deep fat frying practices adopted. Further

from each unit one personnel, handling food preparation (1 cook/ chef per unit),

was interviewed to assess their knowledge/ awareness on adverse effects of re-

heating of fats/ oils and trans fatty acids (TFA) on human health and use of

vanaspati.

The preliminary survey had been conducted on 42 food service outlets in various

parts of Delhi and National Capital Region (NCR) covering north (38.1%), south

(26.2%) and central Delhi (16.7%) as well as NCR (Gurgaon-Haryana; 19.0%)

using the pre-designed interview schedule (ANNEXURE VI). The food

establishments surveyed included Restaurants (R; 19.0%), Indian Fast Food

Joints/ Halwais (IFF; 33.3%), Western Fast Food Joints (WFF; 16.7%), Bakery

shops (BS; 14.3%) and Road side vendors (RV; 16.7%) (Table 4.1.9). To maintain

the confidentiality all the outlets surveyed were allotted appropriate codes based

on their type (Table 4.I.11).

Majority of the food service establishment surveyed were serving western foods

(31.0%), while others were serving North Indian/ Mughlai food (21.4%), snacks

(21.4%) or all types of cuisines (19.4%), with only 3 outlets (7.1%) serving South

Indian foods (Table 4.I.10).

171

Table 4.I.9: Type of Food Service Outlets Selected and Different Food Items

being Sold in them

S.No. Food

Service

Outlet

N

(%)

Food items being prepared/ sold

Fried Baked

1 Restaurants

(R)

8

(19.0)

Poories, Bhatura, Spring

roll, Pakoras, Cutlets,

Vada, Samosa

Pastry, Pizza

2 Indian Fast

Food Joints/

Halwais

(IFF)

14

(33.3)

Cutlet, Kebabs, Chicken,

Papri, Gol Gappe, Cutlets,

Vada, Samosa, French

fries, Burger cutlets, Jalebi

Pizza, Patties,

Muffin, Cake

3 Western

Food Joints

(WFF)

7

(16.7)

French fries, Burger,

Cutlets, Onion rings, Fried

vegetables/chicken, Donuts

Pizza, Breads,

Burger buns,

Muffin, Fruit Pie,

Cake, Pastry

4 Bakery

Shops (BS)

6

(14.3)

Spring rolls, Cutlets Pastry, Cake,

Patties, Cookies,

Biscuits, Rusks,

Pie, Tarts,

Muffins, Bread

5 Road Side

Vendors

(RV)

7

(16.7)

Tikki, Fried aloo chaat,

Pakore, Jalebi

- -

Table 4.I.10 : Details of Eating Outlets Surveyed (N=42)

Zone N (%) Type of Cuisine N (%)

North Delhi

16

(38.1)

All cuisines 8 (19.0)

South Delhi

11

(26.2)

North Indian/

Mughlai 9 (21.4)

Central Delhi 7 (16.6) South Indian 3 (7.1)

NCR (Gurgaon) 8 (19.0)

Western

13

(31.0)

Snacks (fried/ baked) 9 (21.4)

172

Table 4.I.11: Type of Fats/ oils used by Food Service Outlets (for frying/

baking/ shortening) S.

No

Establishme

nt/ Codes

Fats/ oils used for Frying Fats/ oils used for

Shortening

Fats/ oils used

for Baking

1 Restaurants

(R)

R1 Vanaspati, Desi ghee,

Groundnut oil

Vanaspati, Groundnut

oil

Margerine,

Butter

R2 Soybean oil Soybean oil, Vanaspati --

R3 Olive oil, Groundnut oil Olive oil, Ghee,

Groundnut oil

Olive oil

R4 Groundnut oil Groundnut oil, Ghee Baker’s

Shortening

R5 Vanaspati Ghee --

R6 Ghee, Groundnut oil Ghee --

R7 Ghee Ghee --

R8 Desi Ghee Desi Ghee --

2 Indian Fast Food Joints/ Halwais (IFF)

IFF1 Olive oil Olive oil --

IFF2 Ghee, Soybean oil Ghee Bakers

Shortening

IFF3 Ghee, Sunflower oil,

Soybean oil

Ghee, Sunflower oil --

IFF4 Vanaspati, Desi Ghee,

Groundnut oil

Desi Ghee --

IFF5 Ghee, Groundnut oil Ghee, Groundnut oil Baker’s

Shortening

IFF6 Ghee, Desi Ghee, Soybean

oil

Ghee, Soybean oil --

IFF7 Vanaspati, Desi Ghee,

Groundnut oil

Vanaspati, Desi Ghee --

IFF8 Desi Ghee, Soybean oil Desi Ghee, Soybean oil --

IFF9 Vanaspati Vanaspati, Refined

vegetable oil

Margerine

IFF10 Vanaspati, Desi Ghee Vanaspati Baker’s

Shortening

IFF11 Ghee Ghee --

IFF12 Vanaspati Vanaspati --

IFF13 Ghee Ghee --

IFF14 Desi Ghee Desi Ghee Butter

3 Western Fast Food Joints (WFF)

WFF1 Palm Oil -- Butter, Baker’s

Shortening

WFF2 Palm Oil, Soybean oil -- Butter

WFF3 Olive oil, Groundnut oil -- Margerine

WFF4 Palm oil -- Butter

WFF5 Soybean oil -- Butter

WFF6 Palm oil, Soybean oil -- Palm oil,

Margarine

WFF7 Palm oil -- Palm oil,

Butter

4 Bakery

Shops (BS)

BS1 -- -- Butter,

Margarine

173

BS2 -- -- Baker’s

Shortening

BS3 Groundnut oil -- Margarine

BS4 Soybean oil -- Butter,

Margerine

BS5 -- -- Baker’s

Shortening

BS6 -- -- Baker’s

Shortening

5 Road Side Vendors (RSV)

RV1 Vanaspati, Refined

vegetable oil

Vanaspati, Refined

vegetable oil

--

RV2 Ghee Ghee --

RV3 Refined vegetable oil -- --

RV4 Refined vegetable oil Refined vegetable oil --

RV5 Vanaspati, Refined

vegetable oil

Vanaspati, Refined

vegetable oil

--

RV6 Refined vegetable oil Refined vegetable oil --

RV7 Ghee Ghee --

Depending on the type of food establishment a variety of food items were being

prepared and sold. It was noted that these food establishments used different fats/

oils for food preparation particularly for frying and baking. The type of fat being

used by the surveyed food establishments is given in Table 4.I.11

- Data pertaining to the Cooks/ Chefs: For the purpose of this study a total

of 42 chefs/ cooks of different food service establishment were surveyed,

which included 35 cooks/ chefs and 7 road side vendors.

- Age/ Educational status of the Cooks/ Chefs: The mean age of the chefs/

cooks under study was 33.8 years. From the data obtained, it was observed

that out of the total chefs/ cooks surveyed; only 2 were below 20 years of

age, while a majority of them (42.9%) were between the age range of 20 -

30 yrs, with an equal number (n=9; 21.4%) were in the age group on 30-

40 and 40- 50 years. However, 9.5 per cent were above the age of 50

years. (Table 4.I.12).

174

Table 4.I.12 Age/ Educational status of the Chefs/ Cooks

Parameters (N=42) Chefs/ Cooks

N (%)

Age group (years)

< 20 2 (4.8)

20 – < 30 18 (42.9)

30 – < 40 9 (21.4)

40 – < 50 9 (21.4)

50 – < 60 4 (9.5)

Education Status

Illiterate 5 (11.9)

Primary Education 10 (23.8)

Secondary Education 12 (28.6)

Senior-secondary 5 (11.9)

Graduate 10 (23.8)

It was found that the level of literacy was quite high in the chefs/ cooks surveyed

(n=37; 88.1%), with 23.8 per cent respondents educated till graduation, however,

these were chefs/ cooks working either in multinational food chain outlets or in

specialty restaurants requiring good culinary and communication skills. Majority

of the chefs/ cooks had completed their secondary level education (28.6%), while

23.8 per cent had studied till primary and 11.9 per cent up to senior secondary

level. However, there was still a considerable size of respondents who were

illiterate (n=5; 11.9%), these were either the cooks working at small restaurants/

establishments, road side vendors or workers cooking with them (Table 4.I.12).

Deep Fat Frying Practices

- Fats/ Oils used for Frying, Shortening and Baking: It was noted that

most of the eating joints reportedly used vanaspati (21.4%), either alone or

in a blend with other fats/ oils for frying (Figure 4.I.8) Other fats/ oils

which were reportedly being used predominantly included Groundnut oil

and Soybean oil (21.4% each), Palm oil (11.9%), Olive Oil and Sunflower

oil (2.4% each) and Refined vegetable oil (7.1%) respectively. Desi ghee

was also reportedly being used for frying purpose (19.0%) in combination

with other fats/ oils. Interestingly, some eating outlets (n=10; 23.8%)

175

reported the use of “Ghee” without specifying the type (Desi Ghee or

Vanaspati).

- A large majority of the surveyed outlets reportedly used “Ghee” (31.0%)

for shortening. While others were using either vanaspati (19.0%) or desi

ghee (11.9%). Some reported the use of either used (left after frying) or

fresh Soybean oil (7.1%), Groundnut oil (9.5%), Palm oil (11.9%) and

refined vegetable oil (RVO; 11.9%). One outlet was reportedly using Olive

oil for shortening. The data revealed that for the purpose of baking, most

of the cooks/ chefs reportedly used either butter (21.4%) or baker’s

shortening (19.0%). Margarine was used by 16.7 per cent cooks/ chefs,

while a very few reported the use of palm oil (4.8%), and olive oil (2.4%).

It is to be noted that both vanaspati and margarine are partially

hydrogenated fats and are loaded with trans fatty acids. However, the

information on fats/ oils being used could not be obtained from 11.9 per

cent of the outlets where baking and frying was commonly being

employed.

- The equipment used for frying depended upon the type of food item being

prepared. Shallow fat frying is usually done on a griddle (tawa) while deep

fat frying can be done using karahi or electric fryer. Karahi is generally

used in the preparation of bigger items e.g. pakora/ jalebi/ samosa/ mathri/

kachori/ vada etc. while electric fryer is used in the preparation of smaller

items like French fries, spring rolls/ smileys etc. Moreover use of karahi is

more often seen in traditional establishments while the electric fryer is

used by establishments serving western foods. In the present study it was

observed that a majority of the outlets were using a combination of

equipment’s depending upon the nature of food item being fried (Table

4.I.13).

- Majority of the eating outlets were using a combination of karahi, electric

fryer and griddle (n= 9; 21.4%), others were using combination of

176

karahiand griddle (n=6; 14.3%), karahi and electric fryer (n=2; 4.8%)

followed by electric fryer and griddle (n=1; 2.4%). All the Western fast

food joints and other outlets where predominantly western foods were

prepared, used only electric fryers (19%), while remaining were using

karahi (16.7%) and griddle (11.9 %) Electrical fryers have an advantage

over karahi, since the temperature in electrical fryer can be controlled due

to presence of thermostat. This ensures that the temperature of oil being

heated does not go very high there by causing less degradation.

Figure 4.I.8 Distribution of eating outlets by the type of fat/ oil used for the

purpose of frying, shortening and baking (Multiple responses)

Table 4.I.13: Equipment used for Frying of Food Items

Equipment Used N (%)

Karahi 7 (16.7)

Electrical fryer 8 (19.0)

Griddle 5 (11.9)

Karahi, Electric fryer, griddle 9 (21.4)

Karahi, Electric fryer 2 (4.8)

Karahi, Griddle 6 (14.3)

Electric Fryer, Griddle 1 (2.4)

Not Applicable 4 (9.5)

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

21.4 19.0

23.8

21.4 21.4

7.1

2.4 2.4

11.9

19.0

11.9

31.0

9.5

7.1

11.9

2.4 2.4

11.9

2.4 4.8

16.7

21.4

19.0

Percen

t (%

)

Fats/ oils used for frying Fats/ oils used for shortening Fats/ oils used for baking

177

- Duration of heating the fats/ oils before frying: The duration of heating

fat/ oil before frying depends on the amount of fat/ oil being used for

frying, the type of food item being prepared and the metal of the frying

vessel. In the current study, most of the cooks/ chefs were not able to give

a definite answer when they were asked regarding duration of heating the

fats/ oils before frying, therefore approximate responses were obtained

(Figure 4.I.9). The study revealed that nearly one-fourth of the

outlets(26%) reportedly heated fat/ oil for 30 to < 45 minutes prior to

frying, while 17 per cent reportedly heated the oil for < 30 minutes and an

equal number of the respondents (n=7) reportedly heated the fat/ oil for 45

to < 60 minutes before frying. Interestingly a whopping 31 per cent

reportedly heated the fat/ oil for approximately 1 hour or more before

frying. Since, these were only the reported responses; the actual duration

of heating may differ.

Figure 4.I.9 Distribution of eating outlets based on the duration of heating

fat/ oil before frying

- Total Duration of Usage of Fat/ oils: The quality of frying medium is

dependent on its duration of usage. In the outlets surveyed the total

duration of use of fat/ oil for frying varied between 5-18 hours with an

average of 10.6 ± 2.4 hours depending on the type of eating outlet and the

demand of fried foods (Table. 4.I.14). A fair number of commercial outlets

(n=7; 16.7 %) reported that they continued heating karahi/ fryer (1 lot of

oil) for nearly 6 - <8 hours, while about 14.3 per cent of them (n=6)

17%

26%

17%

31%

9%

< 30 minutes 30 - < 45 minutes 45 - < 60 minutes ≥ 60 minutes Do not fry

178

continued heating the same lot of oil for nearly 8- <10 hours. Reported

duration of heating fat/ oil was as high as ≥16 hours at 5 eating outlets. An

equal number of outlets (n=4; 9.5%) reportedly heated/ used the oil for

continuously 12- <14 hours and 14- <16 hours respectively.

- Number of times the fats/ oils are reheated for frying: Reheating refers

to heating of fat/ oil again once the heated fat has been taken off from the

heat source or the heat source has been removed and reportedly leads to

greater degradation in the oil quality. The number of times fats/ oils is

reheated plays an important role in determining its quality. In the present

study, the approximate responses obtained from the cooks/ chefs revealed

that re-heating largely depended on the amount of fat/ oil left after frying

and the number of frying cycles it has completed.

Table 4.I.14: Duration of Use of fat/ oils at different eating outlets

Duration of Use of Oil N % Outlets

<6 hours 2 4.8 BS5, BS6

6 - <8 hours 7 16.7 R5, R6, IFF1, IFF3, IFF7, IFF11, IFF14

8 - <10 hours 6 14.3 R2, R7, IFF10, RV1, RV3, RV6

10- < 12 hours 3 7.1 R3, R4, IFF6

12- <14 hours 4 9.5 R1, IFF4, IFF5, RV2

14- < 16hours 4 9.5 IFF2, IFF9, IFF12, RV4

≥ 16 hours 5 11.9 IFF13, IFF8, RV5, RV7, R8

No response/ Information

refused 7 16.7

WFF1, WFF2, WFF3, WFF4, WFF5, WFF6,

WFF7

Not Applicable 4 9.5 BS1, BS2, BS3, BS4

- However, majority of the respondents (31.0%) reportedly reheated the fats/

oils approximately 5-9 times (frying cycles), while 24 per cent cooks/

chefsreheated them for 10-14 times and 14% reheated fats/ oils 15-19

times. This could lead to great deterioration in the fat/ oil. (Figure 4.I.10).

179

31%

24%

14%

21%

10%

5 - 9 times

10 - 14 times

15 - 19 times

20 - 24 times

Do not fry

It was reported that the frying medium being used for more than 12 hours

would undergo cooling overnight before being reused the following

morning. Even during working hours, many cooks discontinued heating

when there was no demand for fried foods. Intermittent heating and

cooling is more destructive than continuous heating since the production of

peroxides and their highly undesirable decomposition products is repeated

with each cycle of heating and cooling (Clark and Serbia, 1991).

Figure 4.I.10 Distribution of eating outlets by the number of times fats/ oils

were re-heated

In most of the food outlets under study (n= 18; 42.9%) the re-used oil was stored

in canisters/ some other vessels after manual filtering (35.7%) so as to remove the

left over food particles, however, in 38 per cent outlets it was still being stored

without any straining and was allowed to remain in the same karahi in which

frying was done. It is well documented that straining helps in reducing the

degradation (oxidation and formation of free radicals) of oils, however,

information on this was not provided by 7 (16.7%) outlets. Additionally, at several

180

outlets (38%) the frying vessels were left uncovered exposing the oil to

atmospheric oxygen. It has been reported that problems in quality of oil occur in

batch frying operations in restaurants and fast food joints, where frying is

necessarily discontinuous and often carried out by unskilled personnel (Berger,

2005).

The criteria for judging deterioration of the oil was rather subjective and included

visible changes like darkening or thickening of oil and accumulation of deposits.

In the present study the data on reported criteria for determining deterioration of

oil indicates that “change in colour of the oil” was the main criteria indicating oil

deterioration (45.2%), whereas in some outlets (11.9%) turning of oil specifically

into shades of black was considered as a sign of deteriorated oil, this was the

general criteria followed by most of the road side vendors. Interestingly few

eating outlets (7.1%) were using the number of frying cycles as the set point after

which either the oil was replenished or discarded, while some others (14.3%) were

using a combination of number of frying cycles and change in the colour of oil as

deterioration mark”, however, they did not reveal the number of frying cycles

after which the oil was discarded. There was one outlet (RV5) where bad smell of

oil was taken as the sign of oil deterioration (Table 4.I.15). This shows that most

of the food service outlets are still not serious regarding the quality of oil for

frying food items and have adopted a rather casual approach towards this issue.

Utilization of re-heated fats/ oils: Frying fat/ oil as a heat and mass transfer

medium has an important effect on foods fried in it. It can affect the quality of

foods in terms of trans fatty acid content, shelf life, nutrition and eating quality

(Blumenthal, 1991). Utilizing the re-heated fat/ oil can further deteriorate the

quality of fat/ oil. In the present study it was observed that majority of the cooks/

chefs utilized the re-used fat/ oil either for the purpose of cooking (sautéing/ as

shortening) and frying (35.7%) or for cooking alone (31.0%). Interestingly, 7.1

per cent cooks/ chefs reported that the used oil was further sold to road side

vendors; such exploitation is a matter of serious concern because it would lead to

further deterioration of the used fat/ oil and hense the quality of food.

181

Table 4.I.15 Cooking/ Frying Practices Adopted at the Eating Outlets under

Study (N=42)

Details of Eating Outlets Selected

Container used for storing

used oil N (%) Criteria for determining

deterioration of oil N (%)

Canister/ Any other storage

vessel 18 (42.9)

Change in colour of the

oil 19 (45.2)

Retained in Karahi 13 (31.0) Oil turns black 5 (11.9)

No response/ Information

refused 7 (16.7) Oil starts smelling bad 1 (2.4)

Not Applicable 4 (9.5) Follow a fixed number of

heating cycles 3 (7.1)

Storage condition for used oil

Stored after straining 15 (35.7)

Change in colour and

number of frying cycles

(both)

6 (14.3)

Stored without any straining 16 (38.0) No response/ Information

refused 4 (9.5) No response/ Information

refused 7 (16.7)

Not Applicable 4 (9.5) Not Applicable 4 (9.5)

It is important to note that re-heating/ re-frying of oil induces production

of elaidic acid (trans isomer) in the fat/ oil, which is a cause for serious

concern. Moreno et al, 1999 reported that intensive heating of fats/ oils

caused an increase in the amount of trans fatty acids. A very small

percentage of respondents reportedly discarded the degraded oil (Table

4.I.16). However, information could not be obtained on this from 5 cooks/

chefs.

Knowledge, Attitudes and Practices regarding fats and oils: In addition

an attempt was made to assess knowledge of the cooks/ chefs regarding the

adverse effects of re-heating of fats/ oils and trans fatty acids from the

health perspective. Only 7 chefs/ cooks were aware of the adverse effects

of re-heating fats/ oils and reported that prolonged heating was harmful but

182

were unable to assign any reason while 73.8 per cent had not even heard of

not reheating fats/ oils (Table 4.I.17). Regarding consumption of

vanaspati, 57.1 per cent considered it to have a positive impact on health,

whereas only 14.3 per cent considered it to have a negative impact.

Table 4.I.16 Utilization of re-heated fats/ oils

Utilization of re-heated fats/ oils N %

Cooking 13 31.0

Cooking and Frying 15 35.7

Sold to Road Side vendors 3 7.1

Discard the oil 2 4.8

Could not get information 5 11.9

Do not fry 4 9.5

- Reasons for using vanaspati/ hydrogenated fat: Hydrogenated oils

(vanaspati) are commonly being used in India and other countries as a

cooking medium and in various traditional products (Mahungu et al 1999).

From the data attained, it was inferred that the cooks/ chefshad different

reasons for using vanaspati. 45.2 per cent considered vanaspati to be a

cheaper substitute for ghee and 21.4 per cent considered that it adds taste

to the food. According to 16.6 per cent cooks/ chefs, foods prepared in

vanaspati can be stored for a longer time than the ones prepared using any

other oil, interestingly an equal per cent (16.6%) of cooks/ chefs working

with multinational food chain outlets did not consider it as a good choice

of fats/ oils (Table 4.I.17).

183

Table 4.I.17 Knowledge and Awareness among cooks/ chefs regarding re-

heated fats/ oils, vanaspati and trans fatty acids

Knowledge and Awareness among cooks/ chefs

regarding re-heated fats/ oils, vanaspati and trans fatty

acids

n %

Heard of Not Re-heating Fats/ Oils

Yes 7 16.7

No/ Don’t Know 31 73.8

Do Not Fry 4 9.5

Aware of adverse effects of Re-heating Fats/ oils

Yes 7 16.7

Don’t Know/ Not Aware 35 83.3

Is Vanaspati Good for Health

Yes 24 57.1

No 6 14.3

Don’t Know 12 28.6

Reasons for using Vanaspati

It is a cheaper substitute for Desi Ghee 19 45.2

Adds Taste to the Food 9 21.4

Food prepared using vanaspati can be stored for long 7 16.6

Not a good choice 7 16.6

Aware of/ heard of the term "Trans Fats"/ "Trans Fatty

Acids"/ TFA

Yes 7 16.6

No/ Don’t Know 35 83.3

Aware of Adverse effects of Trans fats

Aware 5 11.9

Partially Aware 2 4.8

Not Aware 35 83.3

- Knowledge on Trans fatty Acid: Small data were also gathered from

cooks/ chefs of food outlets regarding their present knowledge on Trans

fats (Table 4.I.17) On being asked about Trans fats approximately 16.6 per

cent were aware of or had heard the term Trans fats, but only 11.9 per cent

actually knew what it is. Most of the workers (83.3%) had absolutely no

knowledge of either trans fats or their adverse effects on human health.

Those who had some knowledge were mostly the personnel employed at

multi-national food chains following some standard specifications.

184

The present preliminary survey is an eye opener in highlighting the quality of fat

being used and the deep fat frying practices adopted at commercial

establishments. A previous study by Goyal and Sundararaj (2009) had also

indicated similar findings and this issue is a cause of serious concern.

4. II LABORATORY ANALYSIS

The laboratory analysis has the following components:

Estimation of TFA content of various fats/ oils at room temperature

Studying the formation of TFA in fats/ oils subjected to varying

temperatures with or without frying the food items

Estimation of TFA content in select food items (fried/ baked/ dairy food

items)

After obtaining necessary permissions, the work was carried out at Foods

Laboratory of Institute of Home Economics Hauz Khas, New Delhi (heating/ re-

heating and frying of fats/ oils) and at the Department of Chemical Engineering,

Indian Institute of Technology, (IIT) New Delhi (for analysis of the fatty acid

profile including the TFA content of the fats/ oils and the food items).

4.II.1 FATTY ACID PROFILE OF EDIBLE FATS/ OILS

On the basis of the preferences marked by the subjects in the preliminary survey, a

total of 17 fats/ oils were selected for laboratory analysis of their fatty acid profile

including TFA content. For each fat/ oil two most preferred brands were selected

and used for analysis, however, for Canola oil, Rice bran oil, refined palmolein oil

and peanut butter only one brand sample could be obtained, while for Desi ghee

and Vanaspati four samples of each were taken for analysis. For blended refined

vegetable oil a total of three samples were obtained. Apart from this, samples of

Coconut oil (cold pressed)* and coconut oil (hard pressed)* were provided by the

Department of Science and Technology (DST) while a sample of Red palm oil**

was obtained from the Institute of Home Economics (IHE) which were also

185

analysed for fatty acid profile including trans fatty acids. Therefore, in all a total

of 33 fats/ oils samples were identified for laboratory analysis. Each fat/ oil was

appropriately coded and where available, the date of manufacturing, date of

expiry, batch number, cost per unit, nutritional information, ingredients and health

claims (if any) were noted for each fat/ oil (Table 4.II.1).

Different fats/ oils used for analysis include:

Yellow Butter: Amul, Britannia

White Butter: Gopala, Local Dairy

Peanut Butter: Fun Foods

Desi Ghee: Madhusudan, Fresh and Pure Cow Ghee, Cow Ghee Gopala,

Milk food

Vanaspati: Dalda, Rath, Panghat, Gagan

Sandwich Spread: Amul Lite Bread Spread

Mustard Oil: Dhara Kachhi Ghani, Panghat

Groundnut Oil: Fortune Goldnut, Dhara

Soybean Oil: Nature Fresh Acti Lite Soybean Oil, Fortune

Sunflower Oil: Nature Fresh Acti Lite Sunflower Oil, Sundrop

Olive Oil: Leonardo (Pomace), Bertulli (Classico)

Canola Oil: Hudson

Rice Bran oil: Ricela

Refined Palmolein oil: Raag

Blended Refined Vegetable Oil: Saffola Gold, Sundrop Heart, Saffola

Tasty

Coconut Oil (Hot Pressed and cold pressed)

Red palm Oil

*DST is keen in finding out the superiority of cold pressed coconut oil over the

hot pressed oil in terms of fatty acid profile including TFA content; if any.

**While Red Palm Oil was analysed as it is being considered as semi-solid fat

to replace the partially hydrogenated vegetable oils for use in bakery

products.

The packaged oil samples purchased from the various markets were kept in

refrigerator (4-6ºC) till those were used for analysis. The brand names and

nutritional information are given in Table 4.II.1 and Annexure (IX).

186

Prior to conducting the detailed fatty acid profile, the procedure for assessment of

fatty acid profile was standardised. For this, a total of 3 known edible fat/ oil

samples were used (Table 4.II.2). As given in methodology, these oils were

converted to their FAMEs and were made to run in GC along with the fatty acid

standards, following which preliminary calculations were done for identification

of various components present in oils to find their compositions.

The amount of saturated (SFA), cis-monounsaturated fatty acid (MUFA), cis-

polyunsaturated fatty acid (PUFA) and Trans fatty acids (TFA) was calculated for

each sample. The amount of SFA, cis-MUFA, cis-PUFA and TFA in the analyzed

samples has been reported as gram/ 100 gram of fat/ oil. To ensure accuracy,

duplicate sample of each fat/ oil were analyzed. In olive oil-F, the estimated

percentage of SFA, cis-MUFA, and cis-PUFA was found to be 36.2, 59.9 and 3.1

respectively. The results of this sample indicate that the SFA content was higher

than the appropriate range specified in codex standard. However, in Olive oil-P,

the SFA, cis-MUFA, cis-PUFA percentage was within the normal range as per the

codex standard. Trans fatty acid was detected in only olive oil-F (TFA; 0.35%). In

both the samples of olive oil, oleic acid was the predominant fatty acids detected.

Higher oleic acid (42-63%) and lower linoleic acid (23-37%) has been reported to

provide the best flavour and stability to the oil (Warner et al, 1997). In case of the

mustard oil sample, the percentage for SFA, cis-MUFA, and cis-PUFA was found

within the range as per the codex standard wherein, about 55% of total fats

comprised of MUFA; and its TFA content was negligible (0.05%). Erucic acid

was the predominant unsaturated fatty acid. In North India, mustard oil is one of

the commonly used cooking oils. Study by Rastogi et al, (2004) has indicated that

use of mustard oil compared to sunflower oil as frying medium, lowers the risk of

ischemic heart disease.

187

Table 4.II.1 Brand Names and Nutrition Related Information of the Fats/ Oils Samples Selected for Analysis

S.No Type

Selected

Brands Code Note Composition Nutritional Information (g/100g of fats/ oils)

Mark/

Certification

Fats of Animal Origin

1 Yellow

pateurised

butter

Amul YBA Best Before 9

Months from

Manufacture

Butter, Common salt

Energy: 722 Kcal, Energy from fat: 720, Total Fat: 80g, SFA:

51g, Cholesterol: 80mg,Sodium:836 mg, CHO: 0g, Protein:

0.5g, Vitamin A: 65 mcg.

--

2 Yellow

pateurised

butter

Britannia YBB Best Before 9

Months from

Manufacture

Milk Solids, Iodized

Salt. Milk Fat: 80%

Minimum

Energy:724Kcal, Protein: 0.4g, Carbohydrate: 0.5g, Fat: 80g,

Sodium:1048 mg, Phosphorous: 15mg, Vitamin A: 650 mcg

--

3 White

Butter

Gopala WBG Best Before 9

Months from

Manufacture

-- -- --

4 White

Butter

Haryana

Dairy WBHD Best Before 9

Months from

Manufacture

-- --

5 Desi Ghee Madusuda

n DGM Best Before 9

Months from

Manufacture

-- Energy: 897 Kcal, Protein: NIL, Carbohydrates: NIL, Total Fat:

99.7g, Sugar: NIL, Fiber: NIL, SFA: 58g, MUFA: 28g, TFA:

5g, PUFA: 2 g, Cholesterol: 211-216mg, Vit A: 2000-3500IU

--

6 Desi Ghee

(cow)

Gopala DGCG Best Before 9

Months from

Manufacture

-- -- --

7 Desi Ghee

(cow)

Fresh &

Pure; Pure

Cow Ghee

DGCFP Best Before 9

Months from

Manufacture

Cow milk fat Energy: 897 Kcal, Protein: 0 Gram, CHO: 0 gram, Total

Fats:99.7grams, SFA:63.0g, MUFA: 24.5g, PUFA: 1.7g, TFA:

3.0g, Cholesterol: 0.4g, Vitamin A: (mcg) 700, Sodium(mg):0,

Phosphorous (mg):0, Calcium: 0 , Sugar:0g

--

8 Desi Ghee Milk food DGMF Best Before 12

Months from

Manufacture

Pure ghee Energy: 808 Kcal, Protein: NIL, Carbohydrates: NIL, Total Fat:

89.5g, Sugar: NIL, Fiber: NIL, SFA: 52.5g, MUFA: 22.4g,

TFA: 3.5g, PUFA: 3.2 g, Cholesterol: 0.19g, Vit A: 2000-

3500IU

AGMARK

(ghee special

grade) E-5

188

Fats/ oils of Plant Origin Code Note Composition Nutritional Information (g/100g of fats/ oils)

Mark/

Certification

9 Peanut

Butter

Fun Foods PBFF Best Before 9

Months from

Manufacture

Roasted peanuts,

Sugar,

Hydrogenated

Edible Vegetable

oil, Edible common

salt

VALUE per 16 gram: Calories: 100, CHO: 3.5g, Dietary fiber:

1g, Sugar:1.5g, Protein:4g, Total Fat: 8g, SFA: 1.5g, TFA: 0g,

Cholesterol:0mg, Sodium: 80 mg, Iron: 1%

--

10 Sandwich

spread

(vegetable

fat)

Amul Lite

Bread

Spread

PHVFA

L

Best Before 9

Months from

Manufacture

Refined Vegetable

Oils, Milk Fat,

Common Salt,

Skimmed Milk

Powder, Emulsifiers

(E#@@), Stabilizers

(E471), Class II

Preservatives (E

202), Acidity

Regulator (E330) &

Antioxidant (E 319).

Total Fat: 70%,

Milk Fat: 10%

Energy: 634 Kcal, Energy from fat: 630 kcal, Total

Fats:70grams, SFA:35g, Cholesterol: 2.4g, Total CHO: 1 gram,

Added Sugar: 0g, Sodium: 650 mg, Added Vitamin A, mcg 900,

Added Vitamin D, mcg: 5. Not a significant source of dietray

fiber and iron. Vitamin A not less than 30 IU per g and Vitamin

D not les than 2 IU per g.

--

11 Mustard oil Panghat ROMP Best Before 9

Months from

Manufacture

Mustard Oil Energy: 900 Kcal, Protein: 0g, Carbohydrate: 0g, Fat: 100g. --

12 Mustard oil Dhara

Kachi

Ghani

ROMD

KG

Best Before 9

Months from

Manufacture

Mustard Oil Energy: 900 Kcal, Protein: 0g, Carbohydrate: 0g, Fat: 100g. --

13

Groundnut

oil

Fortune

Goldnut

ROGF

Best Before 9

Months from

Manufacture

refined groundnut

oil, permitted

antioxidant (E-319)

Energy: 900Kcal, Protein: 0 Gram, CHO: 0 gram, Total

Fats:100grams, Cholesterol: 0mg, Vitamin A, 750 mcg (2500

I.U.) and Vitamin D, 5 mcg (200 I.U.) per 100 gwhen packed

and sold in Gujrat. Free from argemone oil.Vitamin E: 50 mg,

Oryzanol: 1000 mg. Free from Argemone Oil

--

189

14

Groundnut

oil

Dhara

ROGD

Best Before 8

Months from

Manufacture

Groundnut Oil,

Vitamin A & D

Energy: 900kcal, Protein: 0g, Carbohydrate: 0g, Fat: 100gm,

Added vitamin A: 2500 I.U./750 ml, Added Vitamin D: 200

I.U./5 mcg

15

Soybean oil

oil

Fortune

ROSB

Best Before 9

Months from

Manufacture

Refined soybean oil,

Permitted

antioxidant (E-319).

Contains Vitamin A,

750 mcg (2500

I.U.)Vitamin D: 5

mcg (200 I.U.) Free

from Argemone oil

Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total

Fats:100grams, SFA:14g, MUFA: 18g, PUFA: 68g, Omega 3:

6g, other PUFA: 62g, TFA: 0g, Cholesterol: 0g, Added Vitamin

A: 750mcg/2500 I.U., Vitamin D: 5 mcg/ 200 I.U.

--

16

Soybean

Oil

Nature

Fresh

Acti-Lite

Refined

Soybean

Oil

ROSBN

F

Best Before 9

Months from

Manufacture

Soybean oil,

Vitamin E 2273

mcg/100g oil,

Vitamin A 750mcg/

100g oil, Vitamin D

5 mcg/100g oil,

Dimethyl

Polysiloxame (900a)

5 ppm

Energy: 884 Kcal, Protein: 0 Gram, CHO: 0 gram, Total Fats:

100grams, SFA: 104.4g, MUFA: 23.3g, PUFA: 57.9g, TFA:

<0.5g, Cholesterol: 0g, Added Vitamin A 2500 I.I./750 mcg,

Added Vitamin D: 200 I.U./ 5 mcg, Vitamin E: 2273 I.U./ 2273

mcg. Free from Argemone Oil

This oil is

added with

DMPS

(**Diemethyl

Polysiloxane)

as a result the

food fried in

such oil

absorbs lesser

oil; verified

by 2 well

known

laboratories.

17

Sunflower

Nature

Fresh Acti

Lite

Sunflower

Oil

ROSFN

F

Best Before 9

Months from

Manufacture

Sunflower oil, Vit A

750 mcg /100 g oil,

Vit. E 273mcg/

100g oil, Vitamin D

5 mcg/100 g Oil,

Dimethyl

Polysiloxane (900a)-

5 ppm

Energy: 884 Kcal, Protein: 0 Gram, CHO: 0 gram, Total Fats:

100grams, SFA:10.3g, MUFA: 19.5g, PUFA: 65.7g, TFA: <

1g, Cholesterol: 0g, Added Vitamin A 750 mcg, Added

Vitamin D 5 mcg, Vitamin E: 273 mcg. Free from Argemone

Oil

Added with

DMPS, thus

the food fried

in such oil

absorbs lesser

oil; verified

by 2 well

known

laboratories

190

18

Sunflower

Sundrop

ROSF

Best Before 9

Months from

Manufacture

Refined edible

sunflower oil, Vitamin

A, Vitamin D2,

Antioxidant (TBHQ),

anti foaming agent

(Dimethyl

Polysiloxane (DMPS].

Free from Argemone

oil

Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total

Fats:100grams, SFA:9g, MUFA: 25g, PUFA: 66g, TFA:

0g, Cholesterol: 0g, Added Vitamin A: 801mcg/2670 I.U.,

Vitamin E: 50 mcg/50 I.U.

--

19 Ricebran

oil

Ricela RORB

R

Best Before 9

Months from

Manufacture

No mention of

ingridients. Free from

argemone oil,

Contains permitted

anti-oxidants & Anti-

foaming agent

Energy: 900Kcal, Protein: 0 Gram, CHO: 0 gram, Sugar:

0g, Total Fats:100grams, SFA:24g, MUFA: 42g, PUFA:

34g,TFA: 0g, Cholesterol: 0mg, Vitamin E: 50 mg,

Oryzanol: 1000 mg. Free from Argemone Oil

--

20

Olive

Bertulli-

Classico

ROOB

C

Best before 24

months from

manufacture

Olive Oil- Composed

of Refined & Virgin

olive oils.

Energy: 820 kcal, Protein: 0g, CHO: 0g, Total fat: 91g,

SFA: 15g, MUFA: 66 g, PUFA: 10 g, TFA: 0.27g,

Vitamin E: 12 mg, Sodium: 0mg

This product may

become cloudy at

around 45º F. Store

Tightly capped in a

cool dry place

21 Olive Leonard

o,

Pomace

ROOL

P

Oct-12 Refined olive pomace

oil and extra virgin

olive oil (oil

comprising

exclusively olive oils

that have undergone

refining and oils

obtained directly from

olives

Serving size: 1 Tbsp=14g, Servings per container:66,

Values per serving: Energy: 120 kcal, Protein:0g, CHO:0g,

Total fat:14g, MUFA: 10g, PUFA:2g, SFA:2g, TFA:0g,

Cholesterol:0mg, Sodium:: 0mg.

--

191

22 Canola Hudson ROC Best Before 9

Months from

Manufacture

Canola oil, Imported

Refined canola oil

Serving size: 2tsp (10g), serving per container: 88, calories

80, Calories from fat 80, Total fat 9g, Saturated fat: 0.5g,

MUFA: 6g, PUFA: 2.6g, Omega-6: 1.7g, Omega-3: 0.8g,

Trans fat: 0g, Cholesterol: 0g, Sodium: 0g, Sodium: 0g,

Total Carbohydrate: 0g, Dietary fiber: 0g, Sugar: 0g,

Protein: 0g, Protein: 0g, Vitamin E: 1.6mg. Nutritional

Information for 100 g: Total fat 92g, Saturated fat: 7g,

MUFA: 54g, PUFA: 26g, Omega-6: 17g, Omega-3: 9g,

Trans fat: 1g, Cholesterol: 0g, Sodium: 0g, Sodium: 0g,

Vitamin E: 16mg.

--

23 Palmolein Raag

Gold

ROPR Best before 6

months from

packaging when

stored in a dry

place away from

heat & Light

Refined Palmolein

Contains Added

vitamin A, 750 mcg

(2500 I.U) and

Vitamin D, 5mcg (200

I.U.)

Energy: 900kcal, Fat: 100g, SFA: 48g, MUFA: 41g,

PUFA: 11g, TFA:0g, Cholesterol 0mg

--

24 Blended oil Saffola

Gold

RBOS

G

Best Before 9

Months from

Manufacture

Refined Rice Bran Oil

and Refined Safflower

(Kardi) Seed Oil.

Contains Permitted

Antioxidants

[319,330] & Anti

Foaming Agent

[900a]. Free from

Argemone Oil.

Nutrient information per 10 g (serving size); Energy: 90

Kcal, Protein: 0g, Carbohydrate:0g, Total Fat:10 g,

Saturated Fatty Acid: 2.0g, Monounsaturated Fatty Acid:

3.6g, Poly unsaturated Fatty Acid: 4.3g, TFA:0g,

Oryzanol:400mg, Cholesterol 0mg

--

25 Blended oil Sundrop

Heart

RBOS

H

Best Before 9

Months from

Manufacture

Refined Rice Bran Oil

80%, Refined

Sunflower Oil 20%.

Contains TBHQ. Free

from Argemone Oil

Energy: 900 kcal, Proteins: 0g, Carbohydrate:0g, Total

fatty acids: 100g, SFA: 21g, MUFA:46g, PUFA: 33g,

TFA:0g, Cholesterol: 0g, Vitamin E (mg/I.U. **) 50/50,

Oryzanol (mg):500

--

192

26 Blended Saffol

a tasty

RBOS

T

Best before 6

months from

packaging when

stored in a dry

place away from

heat & Light

Refined corn oil (80%

by wt) and refined

safflower seed oil (20%

b wt), contains

permitted anioxidants

(319,330), and anti

foaming agent (900a).

Free from argemone oil

per 10g: Energy:90kcal, Protein:0g, Carbohydrate:0g,

Total fat:10g, Saturated fatty acid: 1.2g, monounsaturated

fatty acid: 2.7g, Poly-unsaturated fatty acid: 6.1g, Trans

fats: 0g, cholesterol omg

AGMARK (Refined

Blend-A)

27 Vanaspati Pangh

at

PHVO

VP

Best Before 9

Months from

Manufacture

palm oil, Sesame oil,

Vitamin A, Vitamin D

Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total

Fats:100 grams, Added Vitamin A: (mcg/IU) 750/2500,

Added Vitamin D: 5/200 (mcg/IU)

--

28 Vanaspati Rath PHVO

VR

Best Before 9

Months from

Manufacture

palm oil, Sesame oil,

Vitamin A, Vitamin D.

Hydrogenated

vegetable fats used -

contains trans fats

Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total

Fats:100 grams, SFA: 47-53, MUFA:44-48, PUFA: 4-7,

Trans fat: 8-20g, Added Vitamin A: (mcg/IU) 750/2500,

Added Vitamin D: 5/200 (mcg/IU)

--

29 Vanaspati Dalda PHVO

VD

Best Before 9

Months from

Manufacture

Palm oil, Palmolein,

Sesame oil, Vitamin A

& Vitamin D.

Energy: 900 Kcal, Protein: 0 Gram, CHO: 0 gram, Total

Fats:100 grams, Cholesterol: 0mg, , Vitamin A: (mcg)

750, Vitamin D: 5 (mcg)

30 Vanaspati Gagan PHVO

VG

Best Before 9

Months from

Manufacture

Palm oil, Rice brans oil,

cotton seed oil, soybean

oil, sesame oil

Energy:900 Kcal, Protein: NIL, Carbohydrates: NIL,

Total Fat: 100g, Vit A: 750mcg (25 IU), Vitamin D2:

5mcg (2 IU)

--

31 Coconut Oil

(Hot Pressed)

COHP -- -- -- --

32 Coconut Oil

(Cold Pressed)

COCP -- -- -- --

33 Red Palm Oil RPO -- -- -- --

CHO: Carbohydrates

193

Table 4.II.2 Fatty Acid Profile of Edible oils Used for Standardization

Type Percentage (g/100g oil)

SFA cis-

MUFA

cis-

PUFA

cis- Total

Unsaturated

fatty acid

TFA cis-

ώ 3

cis-

ώ 6

cis-

ώ 9

Predominate

fatty Acid

Olive oil

Standard

composition

8-

17.1

55-

84.6

3.5-

22.5

- - - - - -

Olive oil-F 36.2 59.9 3.1 63.4 0.35 - 2.9 57.4 Oleic Acid

Olive oil-P 16.6 70.2 11.7 81.9 - 0.24 9.06 70.1 Oleic Acid

Mustard Oil

Standard

composition

1.2-

12.0

35.5-

89.0

16 -

44

Mustard oil 12.4 55.5 30.2 85.7 0.05 10.1 14.8 14.41 Erucic Acid

After standardising the protocol (by analyzing two samples of olive oil and one

sample of mustard oil along with the fatty acid standards) and taking all due

precautions, the fats/ oils samples were analysed for their complete fatty acid profile

including TFA. Each oil sample was analyzed in duplicate to ensure the accuracy of

the results. In total, estimation of fatty acid profile including TFA content has been

carried out for 33 fat/ oil samples.The amount of SFA, cis-MUFA, cis-PUFA and

TFA in these samples have been reported as g/ 100g of fat/ oil (Table 4.II.3 and

4.II.4). Fatty acid profile of the selected samples of fats/ oils indicated that there were

individual differences between the fatty acid composition of oil samples of different

brands of the same oil, such as two brands of mustard oil had variations in their fatty

acid profile. TFA being a major risk factor for heart diseases, insulin resistance,

diabetes and several other health problems (Mozaffarian et al, 2006), occupies the

major focus of the present study.

194

Figure 4.II.1: Fatty Acid Profile of Selected Samples of Fats/ Oils

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

g/

10

0g

SFA cis-TUFA Total TFA

195

4.II.1.1 Fatty Acid Profile of Select Fat/ Oil Samples of Animal Origin

Laboratory analysis of the fatty acid profile of fat/ oil sample of animal origin was

carried out for a total of eight samples (Table 4.II.3 and Figure 4.II.2). The fat

samples of animal origin (yellow butter: YBA and YBB; white butter: WBC and

WBHD; Desi ghee: DGM, DGCFP, DGCG and DGMF) were predominantly high in

saturated fatty acid content (YBA; 65.2%, YBB; 60.6%, WBC; 56.3%, WBHD;

61.5%, DGM; 42.2%, DGCFP; 43.1%, DGCG; 41.3% and DGMF; 55.7%). The fats/

oils with the highest SFA levels were yellow butter (YBA; 65%) and white butter

(WBHD; 61.5%). These animal fats had significantly high levels of cis-MUFA as

compared to cis-PUFA. These samples had oleic and palmitic acid as the predominant

fatty acid. Plamitic acids are solid at room temperature and stable during storage and

frying. Although palmitic acid rich oils show high stability during storage and frying,

however, they are associated with increased LDL cholesterol and have shown to

elevate the risk for heart diseases. Omega 3 fatty acid, though in small amounts was

present in all these samples except for one sample of Desi ghee (DGMF), the levels

were highest in white butter (WBHD; 3.04%) and lowest in yellow butter (YBA;

0.85%). Omega 6 fatty acid was present in all the samples of animal fats ranging from

as low as 0.62 per cent (YBA) to as high as 11.1 per cent (DGM).

Trans fatty acid was also present in all the fat samples of animal origin, however,

there was a wide variation in their TFA content (ranging between 0.68%; White

butter- WBHD to 8.6%; Desi Ghee-DGCG). Results indicate a significant amount of

trans fatty acid in three samples of desi ghee (DGCG; 8.68%, DGMF; 2.2%, DGCFP;

1.72%), while a comparatively lower level in one sample of (DGM; 0.68). The

surprising revelation was presence of higher TFA (8.6%) in Desi Ghee (DGCG)

reported to be prepared from cow’s milk. The TFA content of Desi ghee has been

reported to be 2 % of the total fat in the Indian literature (Ghafoorunissa and

Krishnaswamy, 1994), however, in the present study it ranged between 0.68g to as

high as 8.6g The probable reason for this could be animal’s feed, which can be a

significant cause for high TFA levels in ruminant products.

196

Table 4.II.3: Laboratory Analysis of Fatty acids profile; of Fat Samples Animal

Origin Selected for the Study

Oil

Type

Code Brand Fatty Acid Profile (g/ 100g of fat) Predomi

nant

Fatty

Acid SFA cis-

MUF

A

cis-

PUF

A

cis-

ώ 3

cis-

ώ 6

cis-

ώ 9

cis -

Total

unsatur

ated

fatty

acid

TF

A

Yellow

Butter

YBA Amul

Lite

65.2 31.5 1.4 0.85 0.62 29 32.9 1.8 OA +PA

Yellow

Butter

YBB Britannia 60.6 32.6 3 1.5 1.5 30.3 35.6 1.1 OA +PA

White

Butter

WBC Gopala 56.3 37.6 4.2 2.9 1.3 28.7 41.8 1.6 OA +PA

White

Butter

WBH

D

Haryana

Dairy

61.5 26.3 10.4 3.04 3.06 22.4 36.8 1.09 OA +PA

Desi

ghee

DGM Madhusu

dan

42.2 38.2 13.8 2.4 11.1 34.3 52.1 0.68 OA +PA

Desi

ghee

DGC

FP

Fresh &

Pure;

Pure

Cow

Ghee

43.1 42.1 12.9 2.9 9.2 29.7 55.07 1.7 OA +PA

Desi

ghee

DGC

G

Gopala 41.3 36.6 11.4 1.08 10.3 25.4 48.06 8.6 OA +PA

Desi

ghee

DGM

F

Milk

Food

55.7 34.6 7.1 - 7.1 25.4 41.7 2.2 OA +PA

OA= Oleic Acid, PA= Palmitic Acid, EA= Erucic Acid, LA= Linoleic Acid

197

Figure 4.II.2: Fatty Acid Profile of Selected Samples of Fats of Animal Origin

4.II.1.2 Fatty Acid Profile of Fat/ Oil Samples of Plant Origin

Liberalization and globalization has led to increased availability of many varieties of

edible oils in India. The consumption of vegetable oils has increased by almost

threefolds in developing countries like India. In the present study a wide variety of

fat/ oil samples of plant origin were selected which included fats like peanut butter,

sandwich spread, vegetable oils (mustard, groundnut, soybean, sunflower, rice bran,

olive and canola), blended refined vegetable oils and partially hydrogenated vegetable

oils (PHVO)/ Vanaspati (Table 4.II.4 and Figure 4.II.3)

Erucic acid was the predominant fatty acids found in both the samples of mustard oil

(ROM and ROMDKG), however, these contained low levels of SFA (17.8% and

16.86% respectively) and high levels of cis-MUFA (ROM; 57.08 g/100g and

ROMDKG; 45.8 g/100g) as well as cis- PUFA (ROM; 23.6g/100g and ROMDKG;

31.3g/100g). The TFA content of these samples showed indicated variations, with one

sample (ROMDKG) containing as high as 4.6 per cent of TFA (the highest among the

refined vegetable oils; and barring partially hydrogenated vegetable oils/ vanaspati),

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

Yellow

Butter-A

Yellow

Butter-B

White

Butter-C

White

Butter-D

Desi

ghee-M

Desi

ghee-CFP

Desi

ghee-CG

Desi

ghee-MF

g/

10

0g

SFA cis-MUFA cis-PUFA Total TFA

198

which also had highest level of omega 3 fatty acid (10.3%) and a fair amount of

omega 9 fatty acid (43.07%), while the other sample (ROM) containing 0.95 per cent

per cent of TFA and 18.2% of omega 9 fatty acid.

There were slight individual variations in the fatty acid profile of both the samples of

groundnut oil. Both were low in SFA (ROGF; 30.04% and ROGD; 23.9%), high in

cis-MUFA (ROGF; 42.3% and ROGD; 53.8%) and had average levels of cis-PUFA

(ROGF; 25.03% and ROGD; 21.5%). However, the cis-omega 9 fatty acid was higher

in ROGD (53.8%) as compared to ROGF (34.1%). ROGD also contained small

amounts of trans fatty acid (0.68%) which was absent in ROGF. The predominant

fatty acid found in both these oils was oleic acid.

Both the samples of soybean oil showed approximately similar fatty acid profile;

these had low levels of SFA (ROSB; 17.9%, ROSBNF; 18.05%), average cis-MUFA

(ROSB; 23.8%, ROSBNF; 26.1%), high cis-PUFA (ROSB; 58.2%, ROSBNF; 53.9%)

and omega-9 fatty acid content (ROSB; 23.8%, ROSBNF; 24.3%). While ROSB was

high in cis-omega 3 fatty acid (14.9%), ROSBNF showed higher level of cis-omega 6

fatty acid (38.4%). Trans fatty acid content of ROSBNF was 1.78 per cent which was

absent in ROSB. Linoleic was the predominant fatty acid in both the soybean oil

samples; although essential, it is unstable during storage and frying.

Similar to the soybean oil, both the samples of sunflower oil were high in cis-PUFA

(ROSF; 56.5% and ROSFNF; 54.5%) low in SFA (ROSF; 9.5% and ROSFNF;

12.8%) and had linoleic acid as the predominant fatty acid. Both the samples were

high in cis-omega 6 fatty acid (ROSF; 55.8% and ROSFNF; 53.5%) had average

levels of cis-MUFA (ROSF; 31.1% and ROSFNF; 29.6%) and had significant

amounts of trans fatty acid content (ROSF; 2.7% and ROSFNF; 3.0%).

Oleic acid was the predominant fatty acid present in Olive oil (ROOL, ROOBC) and

Canola Oil (ROC). While Rice bran oil (RORBR) and one sample of refined

blended oil (RBOSH) contained both oleic acid and linoleic acid as the predominant

fatty acids. Oleic acid is liquid at room temperature and relatively more stable during

storage and frying however, it is well known from the literature that oils rich in oleic

acid are more prone to produce undesirable flavour during repeated frying. Further

high percentage of cis-MUFA was found in both the samples of olive oil (ROOL;

199

83.7% and ROOBC; 73.7%), one sample of refined blended oil (RBOSG; 87.08%) as

well as in refined rice bran oil (RBOR; 69.3%). All these samples had low levels of

cis-PUFA (ROOL; 1.77%, ROOBC; 3.5%, RORBR; 12.6% and RBOSG; 5.2%). In

one sample of refined blended oil (RBOSH) cis-PUFA constituted around 78 per cent

of total fatty acids, which was the highest level among all the fats/ oil samples of

animal/ plant origin under study. The trans fatty acid content was undetectable in both

the samples of olive oil and two samples of refined blended oil (RBOST and

RBOSH), however, canola oil, rice bran oil and one sample of refined blended oil

contained around 1.7 per cent, 0.35 per cent and 0.5 per cent TFA respectively.

Nearly 50-60 years back, majority of the households in northern India were using only

desi ghee and mustard oil as the cooking medium. Slowly hydrogenated fats (in the

form of vanaspati) came into the picture. Vanaspati entered India in 1960s as a solid

cooking fat that was promoted as vegetable ghee and within some time it was a

common cooking medium in almost every household. It was being used for the

purpose of cooking, frying and shortening. It was only recently that the health effects

of hydrogenated fats came into lime light and the TFA related health effects surfaced.

In the present study all the samples of partially hydrogenated vegetable oils

(vanaspati; PHVOVG, PHVOVR, PHVOVP, PHVOVD) had almost similar fatty

acid profile. These had high levels of SFA (PHVOVG; 47.08%, PHVOVR; 49.1%,

PHVOVP; 41.9%, PHVOVD; 41.05%), low levels of cis-PUFA (PHVOVG; 5.9%,

PHVOVR; 9.8%, PHVOVP; 7.9%, PHVOVD; 5.2%) and fairly good amount of cis-

MUFA ranging from 27.2 per cent (PHVOVR) to 36.6 per cent (PHVOVP). These

partially hydrogenated vegetable oil samples were predominantly high in oleic acid

and palmitic acid. High levels of trans fatty acids were detected in all the samples of

partially hydrogenated vegetable oils (PHVOVG; 14.6%, PHVOVR; 12.9%,

PHVOVP; 13.3% and PHVOVD; 13.9%).

The TFA content of vanaspati in the Indian literature reports a level of as high as 53

per cent (Ghafoorunissa and Krishnaswamy, 1994). While, the analysis of fatty acid

composition in the NIN laboratory of currently available brands/ batches of vanaspati

sold in market (n=24) across the country showed wide variation in total TFA content,

elaidic acid was reported to be the major trans isomer. The numbers of brands/batches

200

having different range of TFA were reported to be: 11 brands/ batches with 5 - 15%

TFA, 5 brands/ batches with >15-20% TFA and 8 brands/ batches with >20 - 38 %

TFA of total fatty acids. The lower TFA level in some brands/ batches may be due to

use of higher proportion of palm oil or its fractions in the mixture of oils used for

hydrogenation (Ghafoorunissa, 2008).

Amongst all the categories of fats/ oils under study, partially hydrogenated vegetable

oils (vanaspati) had the highest amount of trans fatty acids. It is a matter of serious

concern since partially hydrogenated vegetable oils are being used rather liberally

even in the big urban cities, posing a serious threat to human health.

The coconut oil samples, both cold pressed and hot pressed had 99.6 and 95 per cent

of SFA respectively with undetectable amount of trans fatty acid. However, the cis-

MUFA and cis-PUFA levels estimated for both these samples were below the normal

range specified in codex standard. Coconut oil is the highest natural source of lauric

acid.

Compared to the Red palm oil (SFA; 54.8%, cis-PUFA; 3.4% and cis-MUFA;

40.9%), Refined Palmolein oil (RPOR) had a slightly higher level of SFA (56.5%)

and cis-PUFA (8.7%) and lower levels of cis-MUFA (35.3%) as (RPO) sample. No

TFA could be detected in refined palmolein oil; however, it was present in Red Palm

oil (0.68%). The predominant fatty acids in both these oils were palmitic and oleic

acid. Oleic acid alone constituted around 40.9 per cent and 35.3 per cent of total fat in

red palm oil and refined palmolein oil respectively. Both these oils (RPO and RPOR)

are being viewed as possible replacement for TFA rich fats/ oils. However, according

to Kritchevsky, (2000) red plam oil is considered as the nutritionists’ oil as it is rich in

β-carotene, tocopherols and tocotrienols, which are not only the vitamins or their

precursors but potent natural antioxidants, which also accord greater stability to the

oil.

It has been recommended that from stability point of view frying oils should contain

high amounts of oleic acid (50-65%), fair amounts of linoleic acid (20-30%) and

decreased amounts of α-linolenic acid (not more than 3%).

One sample each of peanut butter (PBFF) and vegetable oil based sandwich spread

(PHVFA) were also analysed for their fatty acid profile including TFA. Both these fat

201

spreads are reportedly considered as healthy fats and are now being preferred by the

elite class over yellow and white butter. The laboratory analysis revealed that Peanut

butter was high in SFA (52.7%) similar to one sample of white butter (WBC; 56.3%),

however, it had higher levels of cis-MUFA (43.1%) and was free of trans fatty acids.

On the other hand the sandwich spread (PHVFA) although low in SFA (25.4%);

similar to one of the samples of groundnut oil and high in cis-MUFA as well as cis-

PUFA (36.8% and 34.1%) had rather high levels of trans fatty acid (4.4%). Thus,

peanut butter and the yellow/ white butter’s turned out to be the preferred fat that can

be used as sandwich spread rather than vegetable oil based sandwich spread.

Owing to the deleterious effects of trans fatty acids on human health, they are the

prime focus of the present study. The study revealed that apart from partially

hydrogenated vegetable oils (vanaspati), which had very high levels of TFA (range;

12.9% to 14.6%), small amounts (range; 0.35% - 4.6%) were also detected in some

refined oils and vegetable fats ranging between 0.35 per cent to 4.6 per cent (ROM;

0.95%, ROMDKG; 4.6%, ROSF; 2.7%, ROSFNF; 3%, ROSBNF; 1.78%, ROGD;

0.68%, ROC; 1.6%, RORBR; 0.35%, RBOST; 0.5%, RPO; 0.68%, PHVFA; 4.4%),

which otherwise are claimed to be free of trans fats (Figure 4.II.4). This may be due to

the formation of TFA during the refining (deodorization) stage. Thus proving the

hypothesis that even refined oils (not all) may in reality not always be trans fat free.

There is paucity of data in Indian literature regarding TFA content of fats/ oils.

However, some data has been reported by Centre for Science and Environment

(Annexure XII), showing variability in the fatty acid profile including TFA content

within each category of fat/ oil (CSE, 2009).

202

Table 4.II.4 Laboratory Analysis of the Fatty acids profile of Fat Samples (of

Plant Origin) Selected for Analysis

OA= oleic Acid, PA= Palmitic Acid, EA= Erucic Acid, LA= Llinoleic Acid

Fats/ Oils Code Brand Fatty Acid Profile (g/ 100g of fat/ oil) Predominant

Fatty Acid SFA cis-

MUFA

cis-

PUFA

cis-

ώ 3

cis-ώ

6

cis-ώ

9

cis -Total

unsaturated

fatty acid

TFA

Peanut

Butter

PBFF Fun

Foods

52.7 43.1 4.01 - 4 43.1 47.2 0 OA+PA

Sandwich

Spread

PHVFA Amul

Lite

24.5 36.8 34.1 - 34.4 36.8 71 4.4 -

Mustard

Oil

ROM Panghat 17.8 57.08 23.6 5.9 17.6 18.2 80.7 0.95 EA

Mustard

Oil

ROMDKG Dhara

Kacchi

Ghani

16.8 45.8 31.3 10.3 13.5 43.07 77.1 4.6 EA

Groundnut

Oil

ROGF Fortune

Goldnut

30.04 42.3 25.03 - 15.5 34.1 67.4 0 OA

Groundnut

Oil

ROGD Dhara 23.9 53.8 21.5 0.46 21.08 53.8 75.3 0.68 OA

Soybean

Oil

ROSB Fortune 17.9 23.8 58.2 14.9 24.7 23.8 82.08 0 LA

Soybean

Oil

ROSBNF Nature

Fresh

18.05 26.1 53.9 8.3 38.8 24.3 80.1 1.78 LA

Sunflower

Oil

ROSF Sundrop 9.5 31.1 56.5 0.7 55.8 31.1 87.6 2.7 LA

Sunflower

Oil

ROSFNF Nature

Fresh

12.8 29.6 54.5 0.9 53.5 29.6 84.1 3 LA

Rice Bran

Oil

RORBR Ricela 16.3 69.3 12.6 1.01 11.6 69.3 82.01 0.35 OA+LA

Olive Oil ROOBC Bertulli

Classico

22.6 73.7 3.5 0.6 2.9 73.7 77.3 0 OA

Olive Oil ROOL Leonardo

Pomace

14.4 83.7 1.77 - 1.7 83.7 85.5 0 OA

Olive Oil ROOF Figaro 36.2 59.9 3.1 - 2.9 57.4 63.4 0.35 OA

Canola Oil ROC Hudson 9.7 57.2 31.3 9.4 21.9 57.2 88.6 1.6 OA

Palmolein

Oil

ROPR Raag 56.5 35.3 8.7 - 8.7 35.3 44 0 OA+PA

Refined

Blended

Oil

RBOSH Saffola

Gold

3.02 18.9 78.04 - 78.04 18.9 96.9 0 LA+OA

Refined

Blended

Oil

RBOSG Sundrop

Heart

7.6 87.08 5.2 - 5.2 87.08 92.3 0 OA

Refined

Blended

Oil

RBOST Saffola

Tasty

45.9 18.7 35.3 - 35.3 18.7 54.07 0.5 OA+LA

Vanaspati PHVOVG Gagan 47.08 32.2 5.9 2.6 3.3 32.2 38.2 14.6 OA+PA

Vanaspati PHVOVP Panghat 41.9 36.6 7.9 0.92 7.02 31.4 44.6 13.3 OA+PA

Vanaspati PHVOVR Rath 49.1 27.2 9.8 5.7 4.02 26.4 37.09 12.9 OA+PA

Vanaspati PHVOVD Dalda 41.05 35.7 5.2 1.5 3.6 19.01 40.9 13.9 OA+PA

Coconut

Oil

COHP Hot

Pressed

95.02 1.6 0.28 - 0.28 1.2 1.9 0 Lauric Acid

Coconut

Oil

COCP Cold

Pressed

99.6 0.28 0 - - 0.28 0.28 0 Lauric Acid

Red Palm

Oil

RPO -- 54.8 40.9 3.4 - 3.4 40.9 44.3 0.68 OA+PA

203

Figure 4.II.3 Fatty Acid Profile of Selected Samples of Fats/ Oils of Plant Origin

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

g/

10

0g

SFA cis-MUFA cis-PUFA Total TFA

204

Figure 4.II.4 Laboratory Analyzed values of the Trans Fatty Acid Content in Selected Samples of Fats/ oil

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00g

/ 1

00

g

205

4.II.2 TFA CONTENT OF HEATED/ RE-HEATED FATS/ OILS

Deep fat frying is a worldwide popular method of food preparation because it is quick

and not very expensive method of cooking which produces desirable fried food

flavour, pleasant colour appeal (golden brown colour) and crisp texture needed in

most of the preparations. However, during the high temperature used in frying lipids

undergo a variety of chemical and physical changes occur due to thermal

decomposition (Stevenson et al, 1984).During deep frying, the fat is continuously

exposed to elevated temperatures in the presence of air. This causes the change in

sensory and nutritional quality of the fat and ultimately a point is reached where it is

no longer possible to prepare high quality fried foods and the frying fat needs to be

discarded. Frying, is also being considered as a contributory factor leading to TFA

formation, which otherwise are thought to be a product of partial hydrogenation. The

formation of TFA during food frying is closely related to the temperature and the oil

use time (Moreno et al. 1999). Considering the negative effects of trans fatty acids on

health, analysis of the nutritional value of fats/ oils used for frying should be made

mandatory.

Several researches have been carried out in the western countries to study the effect of

formation of TFA during frying indicate an increase in the concentrations of trans

isomers with increase in temperature and duration of heating. As a result several

European countries have formed stringent rules and have recommended that the

frying oil temperature must not exceed 180ºC. However, in India due to paucity of

knowledge and data, there are no such guidelines or checks on the temperature of oil.

The food manufacturers/ cooks as per their convenience continue to heat/ re-heat the

fats and oils in large karahi/ fryers at varying temperature and many times rather high

temperature for long hours with intermittent episodes of cooling (as per the demand

for fried foods). All this results in TFA formation heating and re-heating with

intermittent episodes of cooling down which is even more harmful for the human

health. Thus, in view of frying being a common method of food preparation in our

country, an India specific study is very much required to understand the effect of

formation of TFA when oil is constantly heated at high, varying temperatures with

intermittent episodes of cooling. Therefore this part of the present study was designed

to assess the formation of trans fatty acids in edible fats/ oils during heating/ frying,

206

with intermittent cooling and then re-heating wherein experiments were performed in

the laboratory using six different types of fats/ oils. 500 ml of these fats/ oil samples

were heated to 180ºC, maintained at this temperature of 30 minutes before the test

food item (50 g or pre-frozen French fries) were fried in it. Thereafter the same oil

sample was heated further to 220ºC and again maintained at this temperature for 30

minutes and then the test food sample (50 g or pre-frozen French fries) were fried to

golden brown colour. The karahi was then removed from the hot plate and the oil was

allowed to cool for one hour and brought down to room temperature (RT; 30-35ºC).

After this one hour period of cooling the oil was re-heated to 180ºC again and

maintained for 30 minutes, and like the previous exercise the test food was fried; the

oil was further re-heated to 220C and similar procedure of frying was repeated in the

same way. Thus, each fat/ oil sample was subjected to four continued frying in heated/

re-heated fat/ oil samples. For comparison, the fats and oil samples were heated/ re-

heated under similar conditions without frying the test food and this served as their

control counterparts. The fats/ oils selected for heating/ re-heating included:

Soybean oil

Groundnut oil

Olive oil

Canola oil

Desi Ghee

Vanaspati

Using Gas chromatography coupled with flame ionization detector (AOAC Official

Method 996.06) the selected fat/ oil samples were then analyzed for their fatty acid

profile including trans fatty acid content, both before and after subjecting them to

heating/ re-heating at 180ºC and 220ºC, with or without frying the test food item. As

indicated in methodology, prior to initiating the frying cycles with the selected fat/ oil

samples, the entire procedure of heating/ re-heating was standardised with respect to

the quantity of oil, temperature ranges, durations of heating, and the test food to be

fried using Blended vegetable oil-refined (BVO-R). Thereafter these standardized

conditions were employed for the rest of fat/ oil samples. Due to their standard

composition/ measurement and easy availability, pre-frozen French fries (PFFF;

purchased from a local supermarket) were selected as the test food for frying.

207

Initially, the oil samples were subjected to 3 different temperatures i.e. 180ºC, 220ºC

and 240ºC both, with and without frying the food item. However, after the initial

experimentation for the final protocol, only two temperature ranges (180ºC and

220ºC) were shortlisted for heating/ re-frying and frying in heated/ re-heated fats and

oils. These temperature ranges and durations were selected on the basis of studies

carried out by Bansal et al (2009), Martin et al (2007) and the practices reported by

the subjects as per the survey.

Heating Protocol: For each fat/ oil sample, a karahi containing 500ml of the fat/ oil

sample was taken and placed on the hot plate. The temperature sensors were

immersed in fat/ oil taking due caution that the temperature sensor did not touch the

base of the karahi (to avoid any error) and the temperature was set at 180ºC. Once

the temperature reached the set point, it was maintained at 180ºC for 30 minutes and

the first 30 ml of fat/ oil sample was drawn, cooled and stored in a cool box for

analysis. Thereafter, the same fat/ oil sample was heated till 220ºC, maintained at this

temperature for 30 minutes and subsequently 2nd

batch of 30 ml of fat/ oil sample was

drawn. Thereafter the karahi containing fat/ oil was taken off the hot plate and the

fat/ oil was allowed to cool for a period of 60 minutes.

In order to study the effect of re-heating on formation of TFA, the same fat/ oil, was

re-heated (after the cool down period of 60 minutes), and the entire process

(heatingat 180ºC and 220ºC) was repeated again. For each of the selected fat/ oil

sample, a total of 4 fat/ oil samples were drawn (Heating at 180ºC, Heating at 220ºC

cooling down for one hour, re-heating the same oil again at 180ºC and finally re-

heating at 220ºC) over a duration of approximately 7 hours.

Frying Protocol:Similar to the heating protocol, frying protocol was followed

wherein, for each fat/ oil sample, a karahi containing 500ml of the fat/ oil sample was

taken and placed on the hot plate. The temperature sensors were immersed in fat/ oil

taking all due pre-caution the temperature was set at 180ºC. Once the temperature

reached the set point, it was maintained at 180ºC for 30 minutes, thereafter first

frying cycle was carried out. During each frying cycle, 50 gram of food i.e. pre-frozen

French fries (PFFF) were fried. At the end of frying cycle 30 ml of oil was drawn,

cooled and stored in a cool box for analysis. Thereafter the same fat/ oil sample was

heated till 220ºC, maintained at this temperature for 30 minutes and subsequent

frying cycle was performed. Thereafter the karahi containing fat/ oil was taken off the

hot plate and the fat/ oil was allowed to cool for a period of 60 minutes.

In order to study the effect of re-heating on formation of TFA, the same fat/ oil, was

re-heated (after the cool down period of 60 minutes), and the entire process (frying at

180ºC and 220ºC) was repeated again. For each of the selected fat/ oil sample, a

total of 4 frying cycles were carried out (Frying at 180ºC, Frying at 220ºC cooling

down for one hour, frying in the same re-used oil again at 180ºC and finally frying at

220ºC) over a duration of approximately 7 hours.

208

4.II.2.1 Fatty Acid Profile including TFA of the frozen French Fries

prior to frying

Prior to initiating the frying protocol, the fatty acid profile including TFA of the pre-

fried French fries was analyzed using gas chromatography method coupled with flame

ionization detectors.

Table 4.II.5: Brand Name and Nutrition Related Information of the Frozen

French fries

Brand Batch/

Lot No.

Date of

manufacture

Ingredients/

Composition

Nutritional Information

Mc-Cain B 17:03 2-Feb-2011 Potatoes, Edible

vegetable oil

per 100 g: Energy: 196

kcal, Protein:3g, CHO:

37g, Sugar:0g, Total fat:4g,

SFA: 2g, MUFA:1g,

PUFA:1g, TFA:0g,

Cholesterol:0mg

For the assessment of fatty acid profile including the TFA content in the pre-fried

French fries, the sample of the pre-fried French fries was homogenized/ ground and

an accurately weighed representative portion was taken by employing soxhlet method

for extraction. This fat extract was then converted into their fatty acid methyl esters

(FAMEs) which were then run in a chromatogram to identify the fatty acid (FA)

peaks against those of fatty acid standards. (Table 4.II.6). The results per 100g of

French fries indicate that the total fat content was 8.5g, the SFA was more than 50%

of the total fat (5.4g/ 100g food), while the cis-MUFA, cis-PUFA and the cis-total

unsaturated fatty acids (cis-TUFA) levels were 2.09g, 1.0g and 3.1g respectively. No

detectable levels of TFA were present in the pre-fried French fries, indicating that the

test food was free of trans fatty acids (0.0g).

Table 4.II.6: Fatty Acid Profile Including TFA for Pre-fried French Fries (test

food)

Fatty Acid Profile g/ 100g of Pre-fried French fries

Total Fat 8.5

Saturated fatty Acid 5.4

cis-MUFA 2.09

cis-PUFA 1.0

cis-TUFA 3.1

TFA 0.0

209

4.II.2.2 Fatty Acid profile of fat/ oil samples subjected to heating/ re-

heating and frying in heated/ re-heated oils samples

All the unheated edible oils under study had high levels of cis-TUFA, ranging

between 67.3 g/ 100g (refined groundnut oil; ROGF) to 88.6 g/ 100g (refined canola

oil; ROC), moderate to low levels of SFA (9.7 g/ 100g refined canola oil; 30.04g/

100g refined groundnut oil) and the TFA being in negligible amounts ≈ 0.0g/ 100g

(refined olive, groundnut and soybean oil) to 1.6g/ 100g refined canola oil. According

to Tsuzuki (2011), fresh purified edible oil contains low levels of trans fatty acids but

their amount may change when used for cooking and frying. On the other hand the

unheated edible fats under study had substantial amount of SFA and cis-TUFA. The

TFA content of these fats showed a wide variation with desi ghee containing 0.68g/

100g while partially hydrogenated vegetable oil (PHVOD) containing as high as

13.9g/ 100g. A comparison of the fatty acid profile including trans fatty acid of the

unheated fat/ oil samples indicated the change in the fatty acid profile of oil samples

subjected to heating/ re-heating with or without frying the food item.

When the fats/ oils were heated at 180ºC, it was observed that, overall there was an

increase in the SFA and TFA levels with a decrease in the levels of cis-TUFA. Thus

the direct effect of frying or mere exposure to high temperature resulted in the

conversion of cis-TUFA to SFA and TFA, therefore, contributing to a manifold

increase in the levels of TFA.Further when these fats/ oils were re-heated after

cooling down to room temperature, since these had already been heated to 220ºC

earlier, even re-heating up to 180ºC increased the SFA and TFA and decreased the

cis-TUFA content. This change was marginal in most of the oil samples but more

pronounced in the case of fat samples (PHVOD and DGM). However, re-heating

these fat/ oil samples to 220ºC drastically increased the levels of SFA and TFA, with

decreasing levels of cis-TUFA.

On the other hand when frying was carried out in the select fat/ oil samples at 180ºC

and 220ºC, the trend was quite similar to that of heated fat/ oil samples i.e. the SFA

and TFA increased with subsequent frying cycles while the concentration of cis-

TUFA decreased. However, it was noted that the increase in the concentration of TFA

and SFA was not as high as that in the case of heated fat/ oil samples. This difference

210

in the concentrations of SFA, TFA and cis-TUFA could perhaps be attributed to the

test food and the possible mechanism could be the selective absorption/ retention of

SFA and TFA by the food being fried.

The result of this study are not in line with that of a similar study by Bansal et al

(2009), wherein the oil samples undergoing frying showed higher levels of TFA as

compared to the heated oil samples, which the authors have attributed to the TFA

content of the test food being fried. In the present study however, the test food being

free of trans fatty acid (as per the laboratory analysis) could not have contributed to

the TFA in the oil.

4.II.2.2a Fatty Acid profile of Refined groundnut oil sample (ROGF) subjected to

heating/ re-heating and frying in heated/ re-heated oils samples

Refined groundnut oil (ROGF), which is one of the most preferred oil for deep fat

frying at commercial level, when tested for its fatty acid profile including TFA before

subjecting to the heat treatment revealed that the SFA was slightly less than half of

cis-TUFA (SFA- 30.04g/ 100g oil; cis-TUFA- 67.33g/ 100g oil) while TFA was

almost non-existent. After the first heating to 180ºC, the SFA increased by 27.2 per

cent (38.2g/ 100g), while cis-TUFA decreased by 11.2 per cent (59.8g/ 100g), while

TFA interestingly not present initially registered a manifold increase from 0 to 1.6g/

100g (Table 4.II.7). This clearly demonstrates the direct effect of heat on the fatty

acid profile of the oil where in cis-TUFA is getting converted to trans fatty acids as

well as saturated fatty acids.

When the same oil sample was heated and maintained at 220ºC, the SFA and TFA

levels increased to 40.5g/ 100g and 2.10g/ 100 g, pointing to a further increase of 6.0

and 31.3 per cent respectively. On the other hand the cis-TUFA decreased to 55.0g/

100g registering a decrease of 8 per cent. This shows that when the oil is heated to a

higher temperature it increases the formation of TFA.

The same oil sample after heating up to 220ºC and subsequently cooling down to

room temperature was re-heated to 180ºC demonstrated a 9.5 per cent further

increase in the levels of TFA (2.30g/ 100g) and 6.7 per cent increase in the levels of

SFA (43.2g/ 100g), while the cis-TUFA decreased by 14.2 per cent (47.2g/ 100g).

211

This indicates that on subsequent cooling and re-heating of oil even at 180ºC, there is

an increase in the TFA levels. This marginal change in the levels of SFA, cis-TUFA

and TFA is because the oil sample was already exposed to a higher temperature of

220ºC and even re-heating it to 180ºC had an effect, though fringy. Thus the effect of

re-heating at 180ºC could perhaps be attributed more to even the duration of heating

rather than temperature alone. When the same re-heated oil sample was further re-

heated and maintained at 220ºC, compared to the re-heating cycle at 180ºC, it showed

an increase of 11.8 per cent in the levels of SFA (48.3g/ 100g) and 95.6 per cent in the

levels of TFA (4.5g/ 100g) while the cis-TUFA decreased by 0.9 per cent (46.8g/

100g). Compared to heating at 220ºC, reheating the same oil to 220ºC showed a

drastic increase in the TFA levels (114.3%), SFA increased by 19.3 per cent; while

cis-TUFA decreased by 14.9 per cent. Thus the effect of re-heating is rather

detrimental to the oil quality and maximum on TFA.

Similar to the effect of heating, the refined groundnut oil sample when used for

frying, registered an increase in the SFA and TFA contents, while the cis-TUFA

levels decreased. However, in comparison to the oil samples heated at 180ºC, the oil

sample used for frying at 180ºC (first frying cycle) had a 2.9 per cent lower level of

SFA, a 6.3 per cent lower level of TFA with marginally lower levels of cis-TUFA (0.7

%). This difference in the concentrations of SFA, TFA and cis-TUFA could perhaps

be attributed to the test food and the possible mechanism could be the selective

absorption/ retention of SFA and TFA by the food being fried. In a study on

characteristics and compositions of oils during deep fat frying, Tyagi and Vasishtha

(1996) reported an apparent increase in saturated fatty acids content and decrease in

unsaturated fatty acid content as frying time increased.

When the same oil sample was used for frying at 220ºC (second frying cycle), the

fatty acid composition revealed a 7.3 per cent increase in SFA (39.8g/ 100g) and 34.0

per cent increase in TFA content (2.01g/ 100g), while the cis-TUFA (53.4g/ 100g)

decreased by 10.1 per cent as compared to frying at 180ºC (first frying cycle). When

the fatty acid profile of the oil sample used for frying at 220ºC was compared to the

oil samples heated at 220ºC, the results indicated that the oil samples undergoing

second batch of frying at 220ºC showed lower levels of SFA (39.8g/ 100g), TFA

(2.01g/ 100g) as well as cis-TUFA (53.4g/ 100g) in comparison to their heated

212

counterparts. This once again is a pointer that perhaps the test food is selectively

absorbing/ retaining higher levels of SFA and TFA from the oil samples.

The fatty acid profile of the third frying cycle carried out in oil sample subjected to

reheating up to 180ºC (after cooling down to room temperature) demonstrated an

increase of 3.1 per cent in SFA (41.0g/ 100g), 4.5 per cent in TFA (2.10g/ 100g) and

1.5 per cent even in cis-TUFA (54.2g/ 100g) as compared to the fatty acid profile of

oil sample used for frying at 220ºC. It was interesting to note an increase in the

concentration of cis-TUFA, which otherwise was demonstrating a decrease in all the

oil samples undergoing heating or frying procedures. The only possible reason could

be attributed to the cis-TUFA of the test food being fried. In comparison to re-heating,

the oil sample used for re-frying at 180ºC had lower levels of SFA and TFA which are

comparable to the earlier results however, the levels of cis-TUFA were higher. This

shows that the test food was selectively absorbing/ retaining the TFA and SFA from

the oil and in turn was contributing to the cis-TUFA content of the oil.

At the end of the fourth frying cycle carried out in oil re-heated at 220ºC, there was a

10.6 per cent increase in SFA (45.4g/ 100g) and 76.2 per cent increase in the content

of TFA (3.7g/ 100g) as compared to the third frying cycle (frying in re-heated oil at

180ºC), while the cis-TUFA decreased by 8.9 per cent (49.4g/ 100g). Further

compared to frying at 220ºC, re-using the same oil for frying again at 220ºC (after a

cooling to room temperature) there was an increase in the SFA levels by 14.1 per

cent, and that of TFA levels by 84.1 per cent; while the cis-TUFA decreased

marginally by 7.5 per cent. This further accentuates the theory of selective absorption

and retention of SFA and TFA by the test food.

Comparison of the fatty acid profile of the oil used for re-frying at 220ºC with that of

the oil re-heated to 220ºC indicated that in the former case the levels of SFA and TFA

were not as high as in the latter. However,, the cis-TUFA showed an increase of 5.6

per cent, further pointing to the theory of selective absorption/ retention of SFA and

TFA by the test food, while at the same time contributing towards the cis-TUFA level

in the oil. This shows that during heating and frying there is an increase in the levels

of SFA and TFA while the cis-TUFA decreases (Figure 4.II.5).

213

Table 4.II.7: Fatty Acid Profile (including TFA) of Refined Groundnut oil

(ROGF) before and after subjecting to heating/ re-heating and frying in heated/

re-heated oil (g/ 100g)

Treatment Fatty acid profile

SFA cis – TUFA TFA UNHEATED 30.04 67.33 0.00 HEATED AT 180ºC 38.20 59.80 1.60 Change (% Change) 8.16 (27.2%) 7.53 (11.2%) 1.60 HEATED AT 180ºC 38.20 59.80 1.60 HEATED AT 220ºC 40.50 55.00 2.10 Change (% Change) 2.30 (6.0%) 4.80 (8.0%) 0.50 (31.3%) HEATED AT 220ºC 40.50 55.00 2.10 Re-HEATED AT 180ºC 43.20 47.20 2.30 Change (% Change) 2.70 (6.7%) 7.80 (14.2%) 0.20 (9.5%) Re-HEATED AT 180ºC 43.20 47.20 2.30 Re-HEATED AT 220ºC 48.30 46.80 4.50 Change (% Change) 5.10 (11.8%) 0.40 (0.9%) 2.20 (95.6%) HEATED AT 220ºC 40.50 55.00 2.10 Re-HEATED AT 220ºC 48.30 46.80 4.50 Change (% Change) 7.80 (19.3%) 8.20 (14.9%) 2.40 (114.3%) UNHEATED 30.04 67.33 0.00 FRIED AT 180ºC 37.10 59.40 1.50 Change (% Change) 7.06 (23.5%) 7.93 (11.8%) 1.50 FRIED AT 180ºC 37.10 59.40 1.50 FRIED AT 220ºC 39.80 53.40 2.01 Change (% Change) 2.70 (7.3%) 6.00 (10.1%) 0.51 (34.0%) FRIED AT 220ºC 39.80 53.40 2.01 FRIED IN REHEATED OIL AT 180ºC 41.04 54.20 2.10 Change (% Change) 1.24 (3.1%) 0.80 (1.5%) 0.09 (4.5%) FRIED IN REHEATED OIL AT 180ºC 41.04 54.20 2.10 FRIED IN REHEATED OIL AT 220ºC 45.40 49.40 3.70 Change (% Change) 4.36 (10.6%) 4.80 (8.9%) 1.60 (76.2%) FRIED AT 220ºC 39.80 53.40 2.01 FRIED IN REHEATED OIL AT 220ºC 45.40 49.40 3.70 Change (% Change) 5.60 (14.1%) 4.00 (7.5%) 1.69 (84.1%) HEATED AT 180ºC 38.20 59.80 1.60 FRIED AT 180ºC 37.10 59.40 1.50 Change (% Change) 1.10 (2.9%) 0.40 (0.7%) 0.10 (6.3%) HEATED AT 220ºC 40.50 55.00 2.10 FRIED AT 220ºC 39.80 53.40 2.01 Change (% Change) 0.70 (1.7%) 1.60 (2.9%) 0.09 (4.3%) Re-HEATED AT 180ºC 43.20 47.20 2.30 FRIED IN REHEATED OIL AT 180ºC 41.04 54.20 2.10 Change (% Change) 2.16 (5.0%) 7.00 (14.8%) 0.20 (8.7%) Re- HEATED AT 220ºC 48.30 46.80 4.50 FRIED IN REHEATED OIL AT 220ºC 45.40 49.40 3.70 Change (% Change) 2.90 (6.0%) 2.60 (5.6%) 0.80 (17.8%)

214

4.II.2b Fatty Acid profile of Refined Olive oil (ROOLP) subjected to heating/ re-

heating and frying in heated/ re-heated oils samples

Refined Olive oil (ROOLP), which is quite appealing because of its high MUFA

content, especially among the upper middle income group and is often regarded as a

nutritionists choice of oil was also exposed to similar experimentation. The unheated

oil revealed an initial composition of SFA- 14.4g/100g; cis-TUFA- 85.5g, while the

TFA levels were undetectable as in the case of groundnut oil. However, after the first

episode of heating and maintaining the oil to 180ºC the level of SFA increased by29.9

per cent (18.7g/ 100g) while the levels of cis-TUFA decreased by 11.5 per cent

(75.7g/ 100g). This episode of heating also resulted in the formation of TFA (0.42g/

100g) which were absent initially, depicting a manifold increase in its levels (Table

4.II.8, Figure 4.III.6).

When the same oil sample was again heated and maintained at 220ºC, the level of

SFA and TFA further increased by 11.2 per cent (20.8g/ 100g) and 111.9 per cent

(0.89g/ 100g) respectively, while that of cis-TUFA decreased by 5.9 per cent (71.2g/

100g). This re-emphasises the increase in formation of TFA on exposure to high

temperature. When the same oil sample was re-heated at 180ºC, (after cooling down

to RT) the level of SFA increased by 15.9 per cent (24.1g/ 100g) and TFA increased

by 23.6 per cent (1.10g/ 100g), while cis-TUFA registered a marginal decrease of 1.7

per cent (70.0g/ 100g). As already explained, this marginal difference in the fatty acid

profile of the oil was because the oil was already exposed to a higher temperature of

220ºC (during second batch of heating).

However, when the same oil sample was further re-heated to 220ºC, the fatty acid

profile showed a 236.4 per cent increase in the levels of TFA (3.70g/ 100g), and SFA

increased by 6.6 per cent (25.7g/ 100g), while cis-TUFA demonstrated a decrease of

1.3 per cent (69.1g/100g). Compared to oil sample heated to 220ºC, re-heating the oil

to 220ºC indicated a 315.7 per cent increase in TFA (3.7g/ 100g) and 23.6 per cent

increase in SFA (25.7g/ 100g), while cis-TUFA showed a decrease of 3.0 per

cent(69.1g/100g).

215

Table 4.II.8: Fatty Acid Profile (including TFA) of Refined Olive oil (ROOLP)

before and after subjecting to heating/ re-heating and frying in heated/ re-heated

oil (g/ 100g)

Treatment Fatty Acid Profile

SFA cis- TUFA TFA

UNHEATED 14.40 85.50 0.00

HEATED AT 180ºC 18.70 75.70 0.42

Change (% Change) 4.30 (29.9%) 9.80 (11.5%) 0.42

HEATED AT 180ºC 18.70 75.70 0.42

HEATED AT 220ºC 20.80 71.20 0.89

Change (% Change) 2.10 (11.2%) 4.50 (5.9%) 0.47 (111.9%)

HEATED AT 220ºC 20.80 71.20 0.89

Re-HEATED AT 180ºC 24.10 70.01 1.10

Change (% Change) 3.30 (15. %9) 1.19 (1.7%) 0.21 (23.6%)

Re-HEATED AT 180ºC 24.10 70.01 1.10

Re-HEATED AT 220ºC 25.70 69.10 3.70

Change (% Change) 1.60 (6.6%) 0.91 (1.3%) 2.60 (236.4%)

HEATED AT 220ºC 20.80 71.20 0.89

Re-HEATED AT 220ºC 25.70 69.10 3.70

Change (% Change) 4.90 (23.6%) 2.10 (3.0%) 2.81 (315.7%)

UNHEATED 14.40 85.50 0.00

FRIED AT 180ºC 16.70 80.70 0.28

Change (% Change) 2.30 (16.0%) 4.80 (5.6%) 0.28

FRIED AT 180ºC 16.70 80.70 0.28

FRIED AT 220ºC 19.60 77.20 0.51

Change (% Change) 2.90 (17.4%) 3.50 (4.3%) 0.23 (82.1%)

FRIED AT 220ºC 19.60 77.20 0.51

FRIED IN REHEATED OIL AT 180ºC 22.30 74.00 1.40

Change (% Change) 2.70 (13.8%) 3.20 (4.2%) 0.89 (174.5%)

FRIED IN REHEATED OIL AT 180ºC 22.30 74.00 1.40

FRIED IN REHEATED OIL AT 220ºC 23.20 69.26 3.60

Change (% Change) 0.90 (4.0%) 4.74 (6.4%) 2.20 (157.1%)

FRIED AT 220ºC 19.60 77.20 0.51

FRIED IN REHEATED OIL AT 220ºC 23.20 69.26 3.60

Change (% Change) 3.60 (18.4%) 7.94 (10.3%) 3.09 (605.9%)

HEATED AT 180ºC 18.70 75.70 0.42

FRIED AT 180ºC 16.70 80.70 0.28

Change (% Change) 2.00 (10.7%) 5.00 (6.6%) 0.14 (33.3%)

HEATED AT 220ºC 20.80 71.20 0.89

FRIED AT 220ºC 19.60 77.20 0.51

Change (% Change) 1.20 (5.8%) 6.00 (8.4%) 0.38 (42.7%)

Re-HEATED AT 180ºC 24.10 70.01 1.10

FRIED IN REHEATED OIL AT 180ºC 22.30 74.00 1.40

Change (% Change) 1.80 (7.5%) 3.99 (5.7%) 0.30 (27.3%)

Re- HEATED AT 220ºC 25.70 69.10 3.70

FRIED IN REHEATED OIL AT 220ºC 23.20 69.26 3.60

Change (% Change) 2.50 (9.7%) 0.16 (0.2%) 0.10 (2.7%)

216

When the olive oil sample from the same batch was used for frying after heating and

maintaining the oil at 180ºC, the fatty acid composition showed a trend similar to that

of heated oil sample, i.e. the levels of SFA increased (16.7g/ 100g) and cis-TUFA

decreased (80.7g/ 100g), indicating an per cent change of 16.0 and 5.6 respectively as

compared to the unheated oil sample, while the TFA content, which was absent

initially appeared at the level of 0.28g/ 100g. However, in comparison to the oil

samples heated and maintained at 180ºC, the oil sample used for frying after heating

and maintaining at 180ºC showed 10.7 per cent lower levels of SFA, 33.3 per cent

lower levels of TFA and 6.6 per cent higher level of cis-TUFA. This clearly

demonstrates the interchange of the fatty acids from the test food.

After the second frying cycle carried out in heated oil sample maintained at 220ºC,

the SFA and TFA levels further increased by 17.4 (19.6g/ 100g) and 82.1 (0.51g/

100g) per cent respectively, while the cis-TUFA registered a decrease of 4.3 per cent

(77.2g/ 100g). As compared to the oil sample heated at 220ºC, the oil used for frying

at 220ºC showed lower levels of SFA and TFA, pointing to a percentage change of

5.8 and 42.7 respectively. However, the cis-TUFA level in the oil sample used for

frying was higher (8.4%) than that present in oil sample heated at 220ºC. This further

establishes the point of selective absorption/ retention of SFA and TFA by the test

food and in turn contributing to the cis-TUFA content of the oil.

Further, when frying was done in the same oil sample after re-heating and maintaining

the oil at 180ºC (third frying cycle; after cooling down to room temperature), the fatty

acid profile of the oil depicted a 13.8 per cent increase in the SFA (22.3g/ 100g) and

174.5 per cent increase in TFA levels (1.40g/ 100g), while cis-TUFA depicted a

decrease of 4.2 per cent (74.0g/ 100g) as compared to the 2nd

frying cycle. Further, in

comparison to the re-heated oil at 180ºC, the oil used for re-frying at 180ºC, indicated

lower levels of SFA, while the level of cis-TUFA were higher. However, when the

same oil sample was further re-heated to 220ºC for frying (fourth frying cycle), the

SFA increased by 4.0 per cent (23.2g/ 100g), while TFA increased to more than

double, registering an increase of 157.1 per cent (3.60g/ 100g), while cis-TUFA

decreased by 6.4 per cent (69.3g/ 100g). Compared to frying at 220ºC, re-using the

same oil for frying at 220ºC (after a cooling the oil to RT) showed an increase in the

217

SFA (23.2 g/100g) levels by 18.4 per cent, while TFA (3.6g/ 100g) levels increased

by 605.9 per cent.

Compared to the fatty acid profile of the re-heated oil sample at 220ºC, the oil used

for re-frying at 220ºC depicted a 9.7 per cent decrease in the levels of SFA, while

TFA decreased by 2.7 per cent. However, the cis-TUFA demonstrated an increase of

0.2 per cent, further pointing to the theory of selective absorption/ retention of SFA

and TFA by the test food, while at the same time contributing towards the cis-TUFA

level in the oil. This also highlights that refined olive oil, although is high in MUFA

but this positive attribute makes it more susceptible to be converted to trans isomers

during heating/ frying, thus it is suggested that it should not be used for re-frying.

4.II.2c Fatty Acid profile of Refined Soybean oil (ROSB) subjected to heating/ re-

heating and frying in heated/ re-heated oils samples

Refined Soybean oil (ROSB), which is one of the popularly used frying oil both at

commercial as well as household level, when tested for its fatty acid profile including

TFA before subjecting to heat treatment revealed an initial composition of SFA;

17.9g/ 100g oil, cis-TUFA; 82.08 g/100g oil while the TFA was not found in the

detectable range. After the first heating and maintaining the oil sample at 180ºC, the

SFA level increased by 12.1 per cent (20.06g/ 100g), while the cis-TUFA decreased

by 10.6 per cent (73.4g/ 100g). Trans fatty acid, which were undetectable in the

unheated oil sample were also formed (0.6g/ 100g) depicting a manifold increase

(Table 4.II.9, Figure 4.II.7).

When the same oil sample was heated to 220ºC the SFA increased to 21.4 g/ 100g,

while TFA increased by more than double (1.70g/ 100g), depicting an increase of 6.7

and 283.3 per cent respectively. On the other hand the level of cis-TUFA (72.9g/

100g) decreased by 0.7 per cent. Further when the same oil was re-heated to 180ºC

(after cooling down to RT), the SFA increased by 12.6 per cent (24.1g/ 100g), while

TFA registered an increase of 23.53 per cent (2.1g/ 100g), with cis-TUFA

demonstrating a marginal decrease of 2.7 per cent (70.9g/ 100g). When the same oil

sample was further re-heated to 220ºC, the TFA content increased by 76.2 per cent

(3.7g/ 100g) and SFA increased by 9.5 per cent (26.4g/ 100g), while cis-TUFA

decreased by of 6.1 per cent (66.6g/ 100g). Comparing the oil sample heated at 220ºC

to the oil sample re-heated at 220ºC, it was observed that the re-heated oil sample

218

depicted a much higher increase in the levels of SFA and TFA registering a per cent

increase of 23.4 per cent and 117.7 per cent respectively, while cis-TUFA

demonstrated a decrease of 8. 6 per cent.

Similar to the effect of heating, the refined soybean oil sample when used for frying,

after the first frying cycle at 180ºC, registered an increase in the levels of both SFA

(19.9g/ 100g) and TFA (0.36g/ 100g) with a decrease in the levels of cis-TUFA

(77.0g/ 100g), however, in comparison to the oil samples heated at 180ºC the oil

sample used for frying at 180ºC pointed to a 0.8 per cent and 40.0 per cent lower

levels of SFA and TFA with 4.9 per cent higher levels of cis-TUFA. When the same

oil sample was used for frying at 220ºC (second frying cycle), the fatty acid

composition revealed an increase of 9.1 per cent for SFA (21.7g/ 100g) and 316.7 per

cent for TFA (1.50g/ 100g), while the cis-TUFA (72.9g/ 100g) reported a decrease of

5.4 per cent as compared to the first frying cycle at 180ºC. Similar to the result of first

batch of frying at 180ºC, the oil samples undergoing second batch of frying at 220ºC

also showed lower levels of TFA (1.50g/100g) in compared to the oil samples heated

at 220ºC.

When the third frying cycle was carried out, in re-heated oil sample maintained at

180ºC (after cooling down the oil to RT), the oil even though, had attained a higher

temperature of 220ºC during second frying cycle, still demonstrated an increase of 7.4

per cent in levels of SFA (23.3g/ 100g) and 33.3 per cent in the levels of TFA as

compared to the oil sample used for second frying cycle (220ºC). In comparison to the

oil re-heated at 180ºC, the re-heated oil sample undergoing frying at 180ºC had lower

levels of SFA and TFA which are comparable to the previous results however, the

levels of cis-TUFA were higher. This also indicates that the test food was selectively

absorbing the TFA and SFA from the oil and in turn was contributing to the cis-

TUFA content of the oil.

Further, at the end of the fourth frying cycle carried out in re-heated oil at 220ºC

there was an increase of 10.7 per cent in the levels of SFA (25.8g/ 100g) and 60.0 per

cent in the levels of TFA (3.2g/ 100g) as compared to the third frying cycle at 180ºC,

while the cis-TUFA (66.3g/ 100g) decreased by 8.8 per cent. Compared to frying at

220ºC, re-using the same oil for frying again at 220ºC (after a cooling the oil to RT)

demonstrated an increase in SFA by 18.9 per cent, while, TFA increased by 113.3 per

cent and the cis-TUFA decreased by 9.1 per cent. Compared to the fatty acid profile

of the oil re-heated to 220ºC, the re-heated oil used for frying at 220ºC, indicated a 2.3

219

per cent decrease in the levels of SFA, while TFA showed a decrease of 13.5 per cent.

However, the cis-TUFA showed a marginal decrease of 0.5 per cent.

Table 4.II.9: Fatty Acid Profile (including TFA) of Refined Soybean oil (ROSB)

before and after subjecting to heating/ re-heating and frying/ re-frying (g/ 100g)

Treatment Fatty Acid profile SFA cis – TUFA TFA

UNHEATED 17.90 82.08 0.00 HEATED AT 180ºC 20.06 73.40 0.60 Change (% Change) 2.16 (12.1%) 8.68 (10.6%) 0.60 HEATED AT 180ºC 20.06 73.40 0.60 HEATED AT 220ºC 21.40 72.90 1.70 Change (% Change) 1.34 (6.7%) 0.50 (0.7%) 1.10 (283.3%) HEATED AT 220ºC 21.40 72.90 1.70 Re-HEATED AT 180ºC 24.10 70.90 2.10 Change (% Change) 2.70 (12.6%) 2.00 (2.7%) 0.40 (23.5%) Re-HEATED AT 180ºC 24.10 70.90 2.10 Re-HEATED AT 220ºC 26.40 66.60 3.70 Change (% Change) 2.30 (9.5%) 4.30 (6.1%) 1.60 (76.2%) HEATED AT 220ºC 21.40 72.90 1.70 Re-HEATED AT 220ºC 26.40 66.60 3.70 Change (% Change) 5.00 (23.4%) 6.30 (8.6%) 2.00 (117.7%) UNHEATED 17.90 82.08 0.00 FRIED AT 180ºC 19.90 77.02 0.36 Change (% Change) 2.00 (11.2%) 5.06 (6.2%) 0.36 FRIED AT 180ºC 19.90 77.02 0.36 FRIED AT 220ºC 21.70 72.90 1.50 Change (% Change) 1.80 (9.1%) 4.12 (5.4%) 1.14 (316.7%) FRIED AT 220ºC 21.70 72.90 1.50 FRIED IN REHEATED OIL AT 180ºC 23.30 72.70 2.00 Change (% Change) 1.60 (7.4%) 0.20 (0.3%) 0.50 (33.3%) FRIED IN REHEATED OIL AT 180ºC 23.30 72.70 2.00 FRIED IN REHEATED OIL AT 220ºC 25.80 66.30 3.20 Change (% Change) 2.50 (10.7%) 6.40 (8.8%) 1.20 (60.0%) FRIED AT 220ºC 21.70 72.90 1.50 FRIED IN REHEATED OIL AT 220ºC 25.80 66.30 3.20 Change (% Change) 4.10 (18.9%) 6.60 (9.1%) 1.70 (113.3%) HEATED AT 180ºC 20.06 73.40 0.60 FRIED AT 180ºC 19.90 77.02 0.36 Change (% Change) 0.16 (0.8%) 3.62 (4.9%) 0.24 (40.0%) HEATED AT 220ºC 21.40 72.90 1.70 FRIED AT 220ºC 21.70 72.90 1.50 Change (% Change) 0.30 (1.4%) 0.00 (0.0%) 0.20 (11.8%) Re-HEATED AT 180ºC 24.10 70.90 2.10 FRIED IN REHEATED OIL AT 180ºC 23.30 72.70 2.00 Change (% Change) 0.80 (3.3%) 1.80 (2.5%) 0.10 (4.8%) Re- HEATED AT 220ºC 26.40 66.60 3.70 FRIED IN REHEATED OIL AT 220ºC 25.80 66.30 3.20 Change (% Change) 0.60 (2.3%) 0.30 (0.5%) 0.50 (13.5%)

220

4.II.2d Fatty Acid profile of Refined Canola Oil (ROC) subjected to heating/ re-

heating and frying in heated/ re-heated oils samples

Refined Canola Oil (ROC), which is being perceived as one of the best oils

available, with fatty acid profile similar to that of mustard oil and almost negligible

erucic acid content, revealed an initial composition of SFA- 9.7g/ 100g; cis-TUFA-

88.6g/ 100g and TFA; 1.6g/ 100g. It is to be noted that amongst all the refined oils

subjected to heating/ re-heating and frying in the present study, only refined canola oil

had TFA present in it, rest all were almost free of TFA initially. After the first batch

of heating at 180ºC, the SFA level increased by 12.4 per cent (10.9g/ 100g), while

cis-TUFA decreased by 6.6 per cent (82.8g/ 100g). Trans fatty acid, which were

already quite high in the unheated oil sample as compared to other refined oils, also

increased to 2.3g/ 100g, depicting an increase of 43.8 per cent (Table 4.II.10, Figure

4.II.8). When the same oil sample was heated again to 220ºC the SFA increased to

12.4g/ 100g, while TFA level increased to 2.9g/ 100g pointing to an increase of 13.8

and 26.1 per cent respectively. On the other hand cis-TUFA decreased by 3.6 per cent

(79.8g/ 100g).

Further when the same oil was re-heated to 180ºC (after cooling down to RT), the

SFA content increased by 9.7 per cent (13.6g/ 100g) and TFA levels increased by

13.8 per cent (3.3g/ 100g), while cis-TUFA registered a marginal decrease of 2.1 per

cent (78.1g/ 100g). However, when the same oil was re-heated to 220ºC, the TFA

increased by 27.3 per cent (4.2g/100g) and SFA increased by 36.0 per cent (18.5g/

100g) while, cis-TUFA (77.2g/ 100g) registered a decrease of 1.1 per cent. Compared

to the oil sample heated at 220ºC to the oil sample re-heated at 220ºC, it was observed

that the re-heated oil sample depicted a much higher increase in the levels of SFA and

TFA registering a per cent increase of 49.2 and 44.8 respectively, while cis-TUFA

demonstrated a decrease of 3.3 per cent.

Similar to the effect of heated oil samples, the refined canola oil sample used for

frying, after the first frying cycle at 180ºC, depicted an increase in the levels of both

SFA (10.6g/ 100g) and TFA (2.09g/ 100g), while levels of cis-TUFA (87.2g/ 100g)

decreased by 1.6 per cent. In comparison to the oil samples heated at 180ºC the oil

sample used for frying at 180ºC pointed to 2.8 per cent and 9.1 per cent lower levels

of SFA and TFA while the levels of cis-TUFA increased by 5.3 per cent. When the

same oil sample was used for frying at 220ºC (second frying cycle), the fatty acid

composition revealed an increase of 16.0 per cent in SFA (12.3g/ 100g) and 24.4 per

221

cent in TFA (2.6g/ 100g), while the cis-TUFA (84.5g/ 100g) reported a decrease of

3.1 per cent as compared to the first frying cycle at 180ºC. In comparison to the oil

sample heated at 220ºC, the oil sample used for frying 220ºC demonstrated 10.3 per

cent lower levels of TFA (2.6g/100g).

The third frying cycle carried out, in the oil sample subjected to re-heating up to

180ºC (after cooling down to RT), the fatty acid profile demonstrated an increase of

6.5 per cent in SFA (13.1g/ 100g), 23.1 per cent in TFA (3.20g/ 100g), while the cis-

TUFA (75.2g/ 100g) decreased by 11.0 per cent as compared the fatty acid profile of

the oil sample used for frying at 220ºC (second frying cycle). In comparison to re-

heating, the oil sample undergoing re-frying at 180ºC had lower levels of SFA, cis-

TUFA and TFA.

At the end of the fourth frying cycle, carried out in oil re-heated at 220ºC, there was

27.5 per cent increase in SFA (16.7g/ 100g) and 21.9 per cent increase in TFA (3.9g/

100g) as compared to the third frying cycle in re-heated oil at 180ºC, while the cis-

TUFA (72.3g/ 100g) decreased by 3.9 per cent. Further, compared to frying at 220ºC,

re-using the same oil for frying again at 220ºC (after a cooling to RT) showed an

increase in the SFA levels by 35.8 per cent, while TFA levels increased by 50.0 per

cent and the cis-TUFA decreased by 14.4 per cent. This further stresses on the theory

of selective absorption/ retention of SFA and TFA by the test food. Comparison of the

fatty acid profile of the oil used for re-frying at 220ºC with that of the oil used for re-

heating to 220ºC indicated that in the former case the levels of SFA and TFA were not

as high as in the heated oil samples.

222

Table 4.II.10: Fatty Acid Profile (including TFA) of Refined Canola oil (ROC) before

and after subjecting to heating/ re-heating and frying/ re-frying (g/ 100g) Treatment Fatty Acid Profile

SFA cis- TUFA TFA

UNHEATED 9.70 88.60 1.60

HEATED AT 180ºC 10.90 82.80 2.30

Change (% Change) 1.2 (12.4%) 5.8 (6.6%) 0.7 (43.8%)

HEATED AT 180ºC 10.90 82.80 2.30

HEATED AT 220ºC 12.40 79.80 2.90

Change (% Change) 1.5 (13.8%) 3 (3.6%) 0.6 (26.1%)

HEATED AT 220ºC 12.40 79.80 2.90

Re-HEATED AT 180ºC 13.60 78.09 3.30

Change (% Change) 1.2 (9.7%) 1.71 (2.1%) 0.40 (13.8%)

Re-HEATED AT 180ºC 13.60 78.09 3.30

Re-HEATED AT 220ºC 18.50 77.20 4.20

Change (% Change) 4.90 (36.0%) 0.89 (1.1%) 0.90 (27.3%)

HEATED AT 220ºC 12.40 79.80 2.90

Re-HEATED AT 220ºC 18.50 77.20 4.20

Change (% Change) 6.10 (49.2%) 2.60 (3.3%) 1.30 (44.8%)

UNHEATED 9.70 88.60 1.60

FRIED AT 180ºC 10.60 87.20 2.09

Change (% Change) 0.90 (9.3%) 1.40 (1.6%) 0.49 (30.6%)

FRIED AT 180ºC 10.60 87.20 2.09

FRIED AT 220ºC 12.30 84.50 2.60

Change (% Change) 1.70 (16.0%) 2.70 (3.1%) 0.51 (24.4%)

FRIED AT 220ºC 12.30 84.50 2.60

FRIED IN REHEATED OIL AT 180ºC 13.10 75.20 3.20

Change (% Change) 0.80 (6.5%) 9.30 (11.0%) 0.60 (23.1%)

FRIED IN REHEATED OIL AT 180ºC 13.10 75.20 3.20

FRIED IN REHEATED OIL AT 220ºC 16.70 72.30 3.90

Change (% Change) 3.60 (27.5%) 2.90 (3.9%) 0.70 (21.9%)

FRIED AT 220ºC 12.30 84.50 2.60

FRIED IN REHEATED OIL AT 220ºC 16.70 72.30 3.90

Change (% Change) 4.40 (35.8%) 12.20 (14.4%) 1.30 (50.0%)

HEATED AT 180ºC 10.90 82.80 2.30

FRIED AT 180ºC 10.60 87.20 2.09

Change (% Change) 0.30 (2.8%) 4.40 (5.3%) 0.21 (9.1%)

HEATED AT 220ºC 12.40 79.80 2.90

FRIED AT 220ºC 12.30 84.50 2.60

Change (% Change) 0.10 (0.8%) 4.70 (5.9%) 0.30 (10.3%)

Re-HEATED AT 180ºC 13.60 78.09 3.30

FRIED IN REHEATED OIL AT 180ºC 13.10 75.20 3.20

Change (% Change) 0.50 (3.7%) 2.89 (3.7%) 0.10 (3.0%)

Re- HEATED AT 220ºC 18.50 77.20 4.20

FRIED IN REHEATED OIL AT 220ºC 16.70 72.30 3.90

Change (% Change) 1.80 (9.7%) 4.90 (6.4%) 0.30 (7.1%)

223

4.II.2e Fatty Acid profile of Partially hydrogenated vegetable oil (PHVOVD)

subjected to heating/ re-heating and frying in heated/ re-heated oils samples

Partially hydrogenated vegetable oil, also known as vanaspati, is the cheapest

substitute to desi ghee, and the biggest source of TFA in Indian diets. A need was felt

to understand the change in its fatty acid profile when exposed to subsequent heating/

re-heating and frying, therefore it was included in the present study. The unheated

sample of partially hydrogenated vegetable oil (PHVOVD), revealed that SFA and

cic-TUFA were almost equal (SFA- 41.1g/ 100g; cis-TUFA; 40.9g/ 100g), while the

TFA content was as high as 13.9 g/ 100g. When the fat sample was heated and

maintained at 180ºC, the SFA increased by 8.9 per cent (44.7g/ 100g), while cis-

TUFA decreased by 20.5 per cent (32.5g/ 100g). Though, the TFA content increased

by 9.4 per cent, its high initial concentration lead to higher levels, resulting in 15.2g

TFA/ 100g oil. On further heating the fat to 220ºC, SFA registered an increase of 9.4

per cent (48.9g/ 100g) and TFA increased by 5.9 per cent (16.1g/ 100g), while cis-

TUFA decreased by 2.8 per cent (Table 4.II.11 and Figure 4.II.9). When the fat was

further re-heated at 180ºC (after a cooling down to RT), the SFA levels increased by

3.1 per cent (50.4g/ 100g), while TFA increased by 11.2 per cent (17.9g/ 100g), on

the other hand cis-TUFA registered a decrease of 11.1 per cent (28.1g/ 100g). When

the same fat sample was re-heated to 220ºC SFA increased by 1.6 per cent (51.2g/

100g), TFA increased by 4.5 per cent (18.70g/ 100g) while cis-TUFA registered a

decrease of 6.8 per cent (26.2g/ 100g). As compared to heating at 220ºC, re-heating

the same sample to 220ºC increased the SFA and TFA by 4.7 and 16.1 per cent

respectively, while cis-PUFA decreased by 17.1 per cent.

Similar to the heated oil samples, the partially hydrogenated vegetable oil sample

used for frying, after the first frying cycle at 180ºC, demonstrated a per cent increase

of 9.4 and 5.8 respectively in the levels of both SFA (44.9g/ 100g) and TFA (14.70g/

100g). The cis-TUFA (32.3g/ 100g) registered a decrease of 21.0 per cent. In

comparison to the oil samples heated at 180ºC the oil sample used for frying at 180ºC

pointed to 3.3 per cent lower levels of TFA, while SFA and cis-TUFA levels almost

remained the same.

As compared to the first frying cycle at 180ºC, when the same oil sample was used for

frying at 220ºC (second frying cycle), the fatty acid composition registered an

224

increase of 6.5 per cent in SFA (47.8g/ 100g) and 7.5 per cent in TFA (15.8g/ 100g),

while the cis-TUFA (29.2g/ 100g) reported a decrease of 9.6 per cent. Similar to the

result of first frying cycle at 180ºC, the oil samples used for second frying cycle at

220ºC also showed lower levels of SFA, TFA as well as cis-TUFA, in comparison to

their heated counterparts, depicting a per cent decrease of 2.2, 7.6 and 1.9

respectively. This indicates the likely hood of the test food absorbing and retaining

these fats from the oil samples. However, explanation of this aspect requires further

studies.

The third frying cycle carried out, in the fat sample subjected to re-heating up to

180ºC (after cooling down to RT and re-heating it again to 180ºC), demonstrated a

per cent increase of 4.4 in SFA (49.9g/ 100g) and 7.6 in TFA (17.00g/ 100g), while

the cis-TUFA decreased by 4.8 per cent (27.8g/ 100g) as compared the fatty acid

profile of oil sample used for second frying cycle (220ºC). In comparison to re-

heating, the fat sample used for frying in re-heated fat at 180ºC had lower levels of

SFA, cis-TUFA and TFA, pointing to a per cent decrease of 1.0, 1.1 and 5.0

respectively.

As compared to the third frying cycle, the fourth frying cycle carried out in fat re-

heated at 220ºC, there was 1.6 per cent increase in the levels of SFA (50.7g/ 100g)

and 9.4 per cent in the levels of TFA (18.60g/ 100g), while the cis-TUFA (25.6g/

100g) decreased by 7.9 per cent. In comparison to frying at 220ºC, re-using the same

fat for frying again at 220ºC (after a cooling the oil to RT) there was an increase in

SFA by 6.1 per cent, TFA increased by 17.7 per cent while, the cis-TUFA decreased

by 12.3 per cent.

Comparison of the fatty acid profile of the fat re-heated at 220ºC and the re-heated fat

used for frying at 220ºC it was observed that the latter depicted a 1.0 per cent decrease

in SFA, while TFA indicated a decrease of only 0.5 per cent. However, the cis-TUFA

showed a decrease of 2.3 per cent.

Previous studies have also demonstrated that when partially hydrogenated fats are

used, the formation of TFA is generally lower (Aro et al, 1998, Romero et al, 2000) as

has been observed in the present study, however, the high initial levels of TFA results

in a larger concentration of trans isomers in fried food

225

Table 4.II.11: Fatty Acid Profile (including TFA) of Partially Hydrogenated

Vegetable oil(PHVOD) before and after subjecting to heating/ re-heating and frying/

re-frying (g/ 100g)

Treatment Fatty Acid Profile

SFA cis-TUFA TFA UNHEATED 41.05 40.90 13.90 HEATED AT 180ºC 44.70 32.50 15.20 Change (% Change) 3.65 (8.9%) 8.40 (20.5%) 1.30 (9.4%) HEATED AT 180ºC 44.70 32.50 15.20 HEATED AT 220ºC 48.90 31.60 16.10 Change (% Change) 4.20 (9.4%) 0.90 (2.8%) 0.90 (5.9%) HEATED AT 220ºC 48.90 31.60 16.10 Re-HEATED AT 180ºC 50.40 28.10 17.90 Change (% Change) 1.50 (3.1%) 3.50 (11.1%) 1.80 (11.2%) Re-HEATED AT 180ºC 50.40 28.10 17.90 Re-HEATED AT 220ºC 51.20 26.20 18.70 Change (% Change) 0.80 (1.6%) 1.90 (6.8%) 0.80 (4.5%) HEATED AT 220ºC 48.90 31.60 16.10 Re-HEATED AT 220ºC 51.20 26.20 18.70 Change (% Change) 2.30 (4.7%) 5.40 (17.1%) 2.60 (16.1%) UNHEATED 41.05 40.90 13.90 FRIED AT 180ºC 44.90 32.30 14.70 Change (% Change) 3.85 (9.4%) 8.60 (21.0%) 0.80 (5.8%) FRIED AT 180ºC 44.90 32.30 14.70 FRIED AT 220ºC 47.80 29.20 15.80 Change (% Change) 2.90 (6.5%) 3.10 (9.6%) 1.10 (7.5%) FRIED AT 220ºC 47.80 29.20 15.80 FRIED IN REHEATED OIL AT 180ºC 49.90 27.80 17.00 Change (% Change) 2.10 (4.4%) 1.40 (4.8%) 1.20 (7.6%) FRIED IN REHEATED OIL AT 180ºC 49.90 27.80 17.00 FRIED IN REHEATED OIL AT 220ºC 50.70 25.60 18.60 Change (% Change) 0.80 (1.6%) 2.20 (7.9%) 1.60 (9.4%) FRIED AT 220ºC 47.80 29.20 15.80 FRIED IN REHEATED OIL AT 220ºC 50.70 25.60 18.60 Change (% Change) 2.90 (6.1%) 3.60 (12.3%) 2.80 (17.7%) HEATED AT 180ºC 44.70 32.50 15.20 FRIED AT 180ºC 44.90 32.30 14.70 Change (% Change) 0.20 (0.4%) 0.20 (0.6%) 0.50 (3.3%) HEATED AT 220ºC 48.90 31.60 16.10 FRIED AT 220ºC 47.80 29.20 15.80 Change (% Change) 1.10 (2.2%) 2.40 (7.6%) 0.30 (1.9%) Re-HEATED AT 180ºC 50.40 28.10 17.90 FRIED IN REHEATED OIL AT 180ºC 49.90 27.80 17.00 Change (% Change) 0.50 (1.0%) 0.30 (1.1%) 0.90 (5.0%) Re- HEATED AT 220ºC 51.20 26.20 18.70 FRIED IN REHEATED OIL AT 220ºC 50.70 25.60 18.60 Change (% Change) 0.50 (1.0%) 0.60 (2.3%) 0.10 (0.5%)

226

4.II.2f Fatty Acid profile of Desi ghee (DGM) subjected to heating/ re-heating

and frying in heated/ re-heated oils samples

Desi ghee, is a class of clarified butter that originated in India and is commonly used

in Indian and South Asian cuisines and traditional foods. However, owing to its high

cost it is replaced by commercial food manufacturers. The unheated sample of Desi

ghee (DGM), revealed a fatty acid profile of SFA: 42.2g/ 100g; cis-TUFA: 52.1g/

100g, while the TFA content was 0.68g/ 100g. After the first heating to 180ºC, the

SFA increased by 2.1 per cent (43.1g/ 100g), TFA increased by 51.4 per cent (1.40g/

100g), while cis-TUFA decreased by 4.01 per cent (50.01g/ 100g).

On further heating the fat to 220ºC, SFA registered an increase of 7.0 per cent (46.1g/

100g) and TFA increased by 22.2 per cent (1.80g/ 100g), however, cis-TUFA showed

a decrease of 4.8 per cent (Table 4.II.12 and Figure 4.II.10). When the fat was re-

heated up to 180ºC (after a cooling down to RT), the SFA levels increased by 5.4 per

cent (48.6g/ 100g), while TFA increased by 66.7 per cent (3.00g/ 100g), cis-TUFA

also registered a decrease of 15.3 per cent (40.3g/ 100g). Further when the same fat

sample was re-heated to 220ºC, the SFA levels increased by 1.9 per cent (49.5g/

100g) and TFA content increased by 10.0 per cent (3.30g/ 100g), while cis-TUFA

demonstrated a decrease of 5.0 per cent (38.3g/ 100g). As compared to heating at

220ºC, re-heating the same fat sample to 220ºC increased the SFA and TFA by 7.4

and 83.3 per cent respectively, while cis-TUFA decreased by 19.5 per cent.

Similar to the heated oil samples, the desi ghee sample used for frying, after the first

frying cycle at 180ºC, demonstrated increase in the levels of SFA (43.01g/ 100g) and

TFA (1.20g/ 100g), while the cis-TUFA (48.9g/ 100g) depicted a decrease of 6.1 per

cent. However, in comparison to the fat samples heated at 180ºC, the fat sample used

for frying at 180ºC had a 0.2 per cent lower level of SFA and 14.3 per cent lower

level of TFA, with 2.2 per cent lower levels of cis-TUFA.

When the same fat sample was used for frying at 220ºC (second frying cycle), the

fatty acid composition revealed an increase of 6.3 per cent in SFA (45.7g/ 100g) and

33.3 per cent in TFA (1.60g/ 100g), while cis-TUFA (45.8g/ 100g) reported a

decrease of 6.3 per cent as compared to the first frying cycle at 180ºC.

227

Table 4.II.12: Fatty Acid Profile (including TFA) of Desi ghee(DGM) before and after

subjecting to heating/ re-heating and frying/ re-frying

Treatment Fatty Acid Profile

SFA cis-TUFA TFA

UNHEATED 42.20 52.10 0.68

HEATED AT 180ºC 43.10 50.01 1.40

Change (% Change) 0.90 (2.1%) 2.09 (4.0%) 0.72 (51.4%)

HEATED AT 180ºC 43.10 50.01 1.40

HEATED AT 220ºC 46.10 47.60 1.80

Change (% Change) 3.00 (7.0%) 2.41 (4.8%) 0.40 (22.2%)

HEATED AT 220ºC 46.10 47.60 1.80

Re-HEATED AT 180ºC 48.60 40.30 3.00

Change (% Change) 2.50 (5.4%) 7.30 (15.3%) 1.20 (66.7%)

Re-HEATED AT 180ºC 48.60 40.30 3.00

Re-HEATED AT 220ºC 49.50 38.30 3.30

Change (% Change) 0.90 (1.9%) 2.00 (5.0%) 0.30 (10.0%)

HEATED AT 220ºC 46.10 47.60 1.80

Re-HEATED AT 220ºC 49.50 38.30 3.30

Change (% Change) 3.40 (7.4%) 9.30 (19.5%) 1.50 (83.3%)

UNHEATED 42.20 52.10 0.68

FRIED AT 180ºC 43.01 48.90 1.20

Change (% Change) 0.81 (1.9%) 3.20 (6.1%) 0.52 (76.5%)

FRIED AT 180ºC 43.01 48.90 1.20

FRIED AT 220ºC 45.70 45.80 1.60

Change (% Change) 2.69 (6.3%) 3.10 (6.3%) 0.40 (33.3%)

FRIED AT 220ºC 45.70 45.80 1.60

FRIED IN REHEATED OIL AT 180ºC 47.10 40.04 2.80

Change (% Change) 1.40 (3.1%) 5.76 (12.6%) 1.20 (75.0%)

FRIED IN REHEATED OIL AT 180ºC 47.10 40.04 2.80

FRIED IN REHEATED OIL AT 220ºC 48.30 36.70 3.10

Change (% Change) 1.20 (2.6%) 3.34 (8.3%) 0.30 (10.7%)

FRIED AT 220 ºC 45.70 45.80 1.60

FRIED IN REHEATED OIL AT 220ºC 48.30 36.70 3.10

Change (% Change) 2.60 (5.7%) 9.10 (19.9%) 1.50 (93.8%)

HEATED AT 180ºC 43.10 50.01 1.40

FRIED AT 180ºC 43.01 48.90 1.20

Change (% Change) 0.09 (0.2%) 1.11 (2.2%) 0.20 (14.3%)

HEATED AT 220ºC 46.10 47.60 1.80

FRIED AT 220ºC 45.70 45.80 1.60

Change (% Change) 0.40 (0.9%) 1.80 (3.8%) 0.20 (11.1%)

Re-HEATED AT 180ºC 48.60 40.30 3.00

FRIED IN REHEATED OIL AT 180ºC 47.10 40.04 2.80

Change (% Change) 1.50 (3.1%) 0.26 (0.7%) 0.20 (6.7%)

Re- HEATED AT 220ºC 49.50 38.30 3.30

FRIED IN REHEATED OIL AT 220ºC 48.30 36.70 3.10

Change (% Change) 1.20 (2.4%) 1.60 (4.2%) 0.20 (6.1%)

228

The oil samples used for second frying cycle at 220ºC also showed lower levels of

SFA, TFA as well as cis-TUFA, in comparison to their heated counterparts, depicting

a per cent decrease of 0.9, 3.8 and 11.1 respectively.

When the third frying cycle was carried out in the fat sample subjected to re-heating

at 180ºC (after cooling down to RT), the fat sample demonstrated a per cent increase

of 3.1 in the levels of SFA (47.1g/ 100g) and 75.0 in the levels of TFA (2.80g/ 100g),

while the cis-TUFA levels decreased by 12.6 per cent (40.0g/ 100g) as compared the

fatty acid profile of fat sample used for second frying cycle at 220ºC. In comparison

to re-heating, the fat sample used for frying after subjecting to re-heating at 180ºC,

had lower levels of SFA, cis-TUFA and TFA, pointing to a per cent decrease of 3.1,

0.7 and 6.7 respectively.

Further at the end of the fourth frying cycle carried out in fat sample re-heated up to

220ºC there was an increase of 2.6 per cent in SFA (48.3g/ 100g) and 10.7 per cent in

TFA (3.10g/ 100g) as compared to the third frying cycle at 180ºC in re-heated fat,

while the cis-TUFA (36.7g/ 100g) decreased by 8.3 per cent. Compared to frying at

220ºC, re-using the same fat after subjecting to re-heating at 220ºC (after a cooling

the oil to RT) showed an increase in the SFA by 5.7 per cent, while TFA levels

increased by 93.8 per cent. The cis-TUFA decreased by 19.9 per cent.

On comparing the fatty acid profiles of the re-heated sample of desi ghee at 220ºC and

the desi ghee sample used for frying after subjecting to re-heating at 220ºC, it was

observed that the latter depicted a 2.4 per cent lower levels of SFA, 6.1 per cent lower

level for TFA, while cis-TUFA demonstrated a decrease of 4.2 per cent.

229

Figure 4.II.5: Fatty Acid Profile including TFA for heated/ frying samples of

Refined Groundnut oil

Figure 4.II.6: Fatty Acid Profile including TFA for heated/ frying samples of

Refined Olive oil

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

ROOLP ROOLP

180ºC

HEAT

ROOLP

220ºC

HEAT

ROOLP

180ºC

REHEAT

ROOLP

220ºC

REHEAT

ROOLP

180ºC

FRY

ROOLP

220ºC

FRY

ROOLP

180ºC

REFRY

ROOLP

220ºC

REFRY

g/

10

0g

SFA cis-TUFA TFA

230

Figure 4.II.7: Fatty Acid Profile including TFA for heated/ frying samples of

Refined Soybean oil

Figure 4.II.8: Fatty Acid Profile including TFA for heated/ frying samples of

Refined Canola oil

0

10

20

30

40

50

60

70

80

90

ROC

Unheated

ROC

180ºC

HEAT

ROC

220ºC

HEAT

ROC

180ºC

REHEAT

ROC

220ºC

REHEAT

ROC

180ºC

FRY

ROC

220ºC

FRY

ROC

180ºC

REFRY

ROC

220ºC

REFRY

g/

10

0g

SFA cis- TUFA TFA

231

Figure 4.II.9: Fatty Acid Profile including TFA for heated/ frying samples of

Desi Ghee

Figure 4.II.10: Fatty Acid Profile including TFA for heated/ frying samples of

Partially Hydrogenated Vegetable Oil (Vanaspati)

0

10

20

30

40

50

60

DGM

Unheated

DGM

180ºC

HEAT

DGM

220ºC

HEAT

DGM

180ºC

REHEAT

DGM

220ºC

REHEAT

DGM

180ºC

FRY

DGM

220ºC

FRY

DGM

180ºC

REFRY

DGM

220ºC

REFRY

g/

10

0g

SFA cis-TUFA Tºtal TFA

0.00

10.00

20.00

30.00

40.00

50.00

60.00

PHVºD

Unheatedº

PHVOVD

180ºC

HEAT

PHVOVD

220ºC

HEAT

PHVOVD

180ºC

REHEAT

PHVOVD

220ºC

REHEAT

PHVOVD

180ºC

FRY

PHVOVD

220ºC

FRY

PHVOVD

180ºC

REFRY

PHVOVD

220ºC

REFRY

g/

10

0g

SFA cis-TUFA TFA

232

4.II.2.3 Trans fatty acid in heated/ re-heated fats/ oils under study: The unheated

fats/ oils samples varied in their TFA content, with refined soybean oil, refined

groundnut oil and refined olive oil having undetectable amounts of TFA, while desi

ghee and refined canola oil had 0.68g/ 100g and 1.60g/ 100g of TFA respectively,

however, the TFA levels in partially hydrogenated vegetable oil (PHVOD) were

recorded to be as high as 13.90g/ 100g. When these fats/ oils were subjected to

heating at 180ºC. All the three oils which had undetectable amounts of TFA indicated

formation of TFA, clearly depicting that heating leads to generation of TFA (Table

4.II.13 and Figure 4.II.11). The fats/ oil which already had TFA also showed

increased amounts after being subjected to heat treatment. Edible oils like refined

soybean oil, refined groundnut oil and refined olive oil, depicted a manifold increase,

while refined canola oil and even desi ghee almost doubled in their TFA levels.

However, in partially hydrogenated vegetable oil, although the initial content was

very high but on heating at 180ºC, it showed a mere increase of nearly 9 per cent. This

could be due to already high levels of TFA and SFA imparting the desired stability to

the fat.

When these fats/ oils were heated to a higher temperature, there was further increase

in their TFA levels, with refined soybean oil and refined olive oil depicting more than

100 per cent increase in their TFA levels while refined groundnut oil, refined canola

oil and desi ghee pointing towards an increase of 20-30 per cent. Partially

hydrogenated vegetable oil on the other hand indicated an increase of approximately 6

per cent only. However, on re-heating these fats/ oils at 180ºC again, after cooling

down to room temperature, slight increase in the TFA levels were observed, for

refined groundnut oil (9.5%), refined canola oil (13.8%), refined soybean oil (23.5%),

refined olive oil (23.6%) and partially hydrogenated vegetable oil (11.2%), whereas

the TFA levels of desi ghee increased by more than double (66.7%) as compared to

heating at 220ºC. Further, re-heating these fats/ oils increased the TFA levels in all the

fats/ oils however, the per cent increase varied between 4.5 (partially hydrogenated

vegetable oil) to 236.4 (refined olive oil). This shows the varied nature of the fats/ oil

regarding the formation of TFA. The overall trend however, indicates towards an

increase in formation of TFA on subsequent heating.

233

Table 4.II.13: Trans Fatty Acid Content of Heated and Re-heated Fats/ Oils

Temperature/

Treatment

Refined

Soybean

Oil

(g/100g)

Refined

Groundnut

Oil

(g/100g)

Refined

Olive

Oil

(g/100g)

Refined

Canola

Oil

(g/100g)

Partially

Hydrogenated

Vegetable oil

(g/100g)

Desi

Ghee

(g/100g)

Unheated 0.00 0.00 0.00 1.60 13.90 0.68

180ºC Heat 0.60 1.60 0.42 2.30 15.20 1.40

220ºC Heat 1.70 2.10 0.89 2.90 16.10 1.80

180ºC Re-

Heat 2.10 2.30 1.10 3.30 17.90 3.00

220ºC Re-

Heat 3.70 4.50 3.70 4.20 18.70 3.30

Table 4.II.14: Trans Fatty Acid Content of Fats/ Oil Samples used for Frying/

Re-frying

Temperature/

Treatment

Refined

Soybean

Oil

(g/100g)

Refined

Groundnut

Oil

(g/100g)

Refined

Olive

Oil

(g/100g)

Refined

Canola

Oil

(g/100g)

Partially

Hydrogenated

Vegetable oil

(g/100g)

Desi

Ghee

(g/100g)

Unheated 0.00 0.00 0.00 1.60 13.90 0.68

180ºC Fry 0.36 1.50 0.28 2.09 14.70 1.20

220ºC Fry 1.50 2.01 0.51 2.60 15.80 1.60

180ºC Re-Fry 2.00 2.10 1.40 3.20 17.00 2.80

220ºC Re-Fry 3.20 3.70 3.60 3.90 18.60 3.10

234

Figure 4.II.12Trans Fatty Acid Content of Heated and Re-heated Fats/ Oils

Figure 4.II.13:Trans Fatty Acid Content of fat/ oil samples used for Frying/ Re-

frying

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

20.00

Refined

Soybean Oil

Refined

Groundnut Oil

Refined Olive

Oil

Refined

Canola Oil

Desi Ghee Partially

Hydrogeneted

Vegetable Oil

Unheated 180ºC Fry 220ºC Fry 180ºC Re-Fry 220ºC Re-Fry

235

4.II.2.4 Trans fatty acid in the fats/ oils used for frying after subjecting to

heating/ re-heating under the study: In the present study it was observed that

similar to the results of heated fat/ oil samples, there was an increase in the levels of

TFA after each frying cycle in heated/ re-heated fats/ oils. However, in comparison to

the heated/ re-heated fat/ oil samples, the fats/ oils undergoing frying had lesser levels

of TFA. This could have been due to the absorption of the TFA content by the test

food being fried in it. Estimation of TFA in the fried test food could have given a

clearer picture of the entire mechanism however; this could not be undertaken since it

was not in the purview of the study, moreover, the time and resource constraints did

not allow this segment to be aligned in the present study. This segment can definitely

be taken up as independent study in the future.

In a study by Romero et al, (2000) it was suggested that frequent addition of fresh

oil in between the frying cycles minimizes the increment in trans fatty acids.

However, in the present study this aspect was not included as it was outside the scope

of the study.

The formation of TFA during food frying is closely related to the process temperature

and oil use time (Martin et al, 2007). The results of the present study are in line with

study by Moreno et al (1999), who evaluated the effects of temperature and time on

the formation of trans isomers during sunflower oil heating in an open container and it

was observed that trans unsaturations started to increase at 150ºC and became much

more significant from 250ºC onwards. After heating for 20 minutes at 200ºC, 250ºC,

and 300ºC, increasing of 356.5%, 773.9%, and 3026.1%, respectively, in the

concentration of trans isomers in relation to the initial values (0.22 mg/g) were

observed.

The present study depicted an increase in the levels of saturated and Trans fatty acids,

with each episode of heating (with or without the food frying in it) as compared to the

unheated samples (Table 4.II.14 and Figure 4.II.13). While the levels of cis-total

unsaturated fatty acids decreased in all the heated and fried oil samples with respect to

the unheated fat/ oil samples. Several studies have shown deep-fat frying decreases

the content of unsaturated fatty acids in frying fat and oil as compared to unheated oil

samples (Alireza et al, 2010). The per cent increase in the levels of SFA and TFA

continued to increase with each frying cycle with respect to unheated fat/ oil samples.

236

Their percentage continuously increased upon reheating and refrying at same

temperature. Similar trend was noticed in oil samples used for frying/ re-frying with a

slight decrease in TFA concentrations as compared to corresponding heated samples.

The per cent increase in the levels of TFA in the saturate rich fats was less as

compared to high cis-TUFA oils. Although oils with high saturated fatty acids content

show unique stability during frying but are least desirable from a nutritional and

health point of view. In a study by Bansal et al (2009), it was shown that the test oil

samples undergoing frying had more of TFA levels as compared to their heated

counterparts due to the high content of TFA in the test food samples (Pre-frozen

French fries), however, in the present study the test food was free of trans fats as

indicated in the laboratory analysis, thus it is hypothesized that the fried fats/ oils

undergoing frying will have less amount of TFA as compared to their heated

counterparts because the test food fried in these samples was absorbing TFA from the

oil. This can be based on the results of TFA estimation of the pre-fried French fries,

which showed no TFA levels, this was also compared to the nutritional information

given on the nutrition label of the pre-fried frozen French fries as well as the

ingredient list which showed no presence of hydrogenated/ partially hydrogenated

vegetable fat. The laboratory analysis of the fried French fries could have given a

clearer picture, however, it could not be undertaken due to constraint of time and

resource. Overall the study results were able to demonstrate the effect of high

temperature heating/ re-heating of fats/ oil on formation of TFA, which is a common

practice at commercial level.

The results not only showed an increase in the overall percentage of TFA but also in

SFA. This indicates that oil subjected to high temperature heating / re-heating though

have low levels of TFA and that of SFA initially, end up having higher concentrations

of both (TFA and SFA), which is least desired nutritionally. This study was also able

to demonstrate that TFA are also produced during the process of frying, which was

still not clearly established. Further the results of this study can be used to project the

adverse effects of high temperature heating/ re-heating of fats/ oils and plan suitable

strategy in developing and imposing strict guidelines regarding maintaining a specific

temperature of the fat/ oil during frying and changing of oils after a fixed number of

frying cycles as has been done in several western countries.

237

4.II.3 ESTIMATION OF TFA CONTENT IN SELECT FOOD ITEMS (FRIED/

BAKED/ DAIRY FOOD ITEMS)

The consumption of foods high in trans fatty acids have been shown to have adverse

effect on human health. Studies have shown a correlation between trans fatty acid

intake and a change in blood lipid profile as well as a relationship between trans fatty

acids intake and risk of cardiovascular diseases (Bhardwaj et al, 2011b). In addition, it

has also been shown to increase the risk of breast cancer and prostate cancer; insulin

resistance which is a feature of type 2 diabetes; age related macular degeneration

which is a leading cause of visual impairment and blindness in developed countries

and adverse effects on child and maternal health. Experimental and epidemiological

studies have shown strong need of in depth profiling of trans fatty acid levels in

different food and in the human diet, and the factors that lead to alteration in the trans

fatty acid content in oils and fats.

In view of the scarcity of data on the TFA content of Indian food items, in this section

of the present study, an attempt was made to estimate the complete fatty acid profile

including TFA of select fried, baked and dairy food items. On the basis of the

preferences of commonly consumed fried/ baked/ dairy food items indicated by the

subjects in the preliminary questionnaire, a total of 48 food items were identified,

however, due to resource constraint only 23 food items could be analysed for the

estimation of their fatty acid profile including TFA content which included 11 fried

foods, 6 baked foods, 5 dairy food items and 2 samples of mayonnaise (vegetarian and

with egg).

These selected food items were purchased from retail stores or restaurants in Delhi/

NCR and were stored at 4ºC - 6ºC. Prepared foods purchased from restaurants were

analyzed either on the same day or next day (after storing at 4ºC-6ºC) while the

packaged food items were analyzed within three days of the purchase. Where

available, the nutritive value, ingredients, fat sources, batch number, date of

manufacture and other details listed on the package label were recorded (Table

4.II.15).

238

The list of food items analysed for their fatty acid profile including TFA content

includes the following:

Fried Foods:

o Potato chips, Bhujiya, Samosa, Tikki, Bread pakora, Fried Aloo chaat,

Parantha, Bhatura, Gulabjamun, French Fries, Frozen French Fries

Baked Foods:

o Biscuits, Rusks, Patties, Pastry, Pizza, Burger

Dairy Products and other foods:

o Milk, Curds, Cottage cheese, Cream, Cheese Slice and 2 samples of

mayonnaise (vegetarian and with egg).

239

Table 4.II.15: Brand Names and Nutrition Related Information of the Food Samples Selected for Analysis

Food Items Brand/

Shop Code

Batch no/

Lot No. Date of

Mfg/ Pkg Date of

Purchase Date of

Expiry Composition

Nutritional

Information Mark/

Certification

Fried Foods

Potato

Chips Kakaji FFPCK --

19-Jan-

2012 30-Jan-

2012 Best Before

18/Mar/2012 Potato, Edible oil,

Edible salt

per 100g: Energy: 548.6

kcal, Protein: 7.1g, Total

fat: 36.6g, Cholesterol: 0

mg, Carbohydrates; 53

g; TFA:0g,

Vegetarian

Mark

Bhujiya Bikaneri FFBB BICCA 22-Jun-11 2-Jul-2011

Best before

22/12/11.

Store in cool

dry, hygienic

place, protect

the contents

from direct

sunlight

Edible vegetable

oil, Husked dew

gram (41.5%),

Husked gram

(8.5%), Edible

common salt,

spices and

condiments

per 100g: Energy:610.13

kcal, Protein: 13.5g,

Total fat: 46.9g, SFA:

11.9g, PUFA:23.3g,

MUFA: 10.5g, TFA:0g,

Carbohydrate: 33.4g,

Sugar:0g, Fiber:2.3g,

Sodium: 1075.1mg,

Cholesterol:0mg

Vegetarian

Mark

Samosa

Shefali

sweet shop FFSS -- -- 25-Jul-11 -- -- -- --

Bread

Pakora

Roadside

vendor FFBPR -- -- 28-Jul-11 -- -- -- --

Parantha Roadside

vendor FFPR -- -- 2-Aug-11 -- -- -- --

Bhatura

Evergreen FFBhEG -- -- 8-Aug-11 -- -- -- --

Gulabjamun Bikaner FFGJB -- -- 20-Mar-12 -- -- -- --

240

Tikki

Roadside

vendor

FFTRV -- -- 16-Aug-11 -- -- -- --

Fried Aloo

Chaat

Roadside

vendor

FFACRV -- -- 21-Aug-11 -- -- -- --

French

Fries

Bikaner FFFFB -- -- 20-Mar-12 -- -- -- --

Baked Food

Cookies

Rainbows BFCR -- -- 20-Mar-12 -- -- -- --

Patty

Rainbows BFPR -- -- 2-Sep-11 -- -- -- --

Pastry

Shefali BFPS -- -- 8-Sep-11 -- -- -- --

Pizza

Rainbows BFPR -- -- 11-Sep-11 -- -- -- --

Burger

Rainbows BFBR -- -- 19-Sep-11 -- -- -- --

Rusk

MAQ Bread

Toast

BFRL

SA005

Jan-12

20-Mar-12

Best before 6

months from

Packaging

Wheat flour,

sugar, salt, bakery

shortening, milk

powder, semolina,

yeast, baking

powder, added

flavour

Per 100 g: Energy; 420

kcal, CHO; 81.54 g, Fat;

6.60 g, Protein; 8.84g

Vegetarian

Mark

241

Dairy Food

Milk Full

Cream

DMS Milk

DFDMSMFC

221/R-

MMPO/1995

5-Feb-11

5-Feb-11

Use by: 5 Feb

2011, when

stored

refrigerated

below 8 C

Pasteurized full

cream milk

Per 100 ml: fat:6%,

SNF:9.0% Energy:

89kcal, Protein:3.4g,

CHO: 5.1g, Fat:6.2g,

Calcium:150mg

ISO

22000:2005

& ISO

14000:2004

certified

organization

Curds

Mother

Dairy

DFMDC

D10314Ag1-

4 1149

31-Jan-11

2-Feb-11

Best before 10

days from

manufacture

when stored

refrigerated

below 8ºC

Milk, Water, Milk

Solids, and Lactic

acid culture

Per 100 g: Energy: 75

kcal, Protein: 3.7g,

CHO: 5.0g, Fat: 4.5g,

Calcium: 168mg

--

Cream

Amul

DFCRA

GO38

7-Feb-11

5-Mar-11

Best before

120 days from

manufacture

when stored

in a cool and

dry place.

After opening

refrigerate and

use within 4

days

low fat cream

containing Milk

fat 25% minimum.

Per 100 g: Energy: 246

kcal, energy from fat:

225kcal, protein: 2g,

total fat: 25g, SFA: 16g,

Cholesterol: 68mg,

Sodium: 34mg, Total

CHO: 3.2g, Added

sugar: 0.0g, Calcium:

100mg. Not a significant

source of dietary fibre,

vitamin C and iron.

Approx values

242

Cottage

Cheese

Local DFCCL -- -- 20-Mar-12 -- -- -- --

Cheese

Slice

Britannia

DFBCS

Lot no:

JLRA

Dec-10

8-May-11

Best before 9

month of

packaging,

when stored at

4 C under

hygenic

conditions

Cheese, milk

solids, idodised

salt, Emulsifier,

(E331, E 339),

Acidifying agent

(E330, E 260),

preservative (E

200), Colour (E

160a (ii). Contains

permitted colours

Per 100 g: Energy: 309,

Protein: 17.0g, CHO:

4.0g, sugar:0g, Fat:

25.0g, Sodium: 1426mg,

Calcium: 564mg,

Phosphorous: 312mg,

Vitamin A: 416mg

Vegetarian

Mark

243

Other Foods

Vegetarian

Mayonnaise

Fun Foods

MSCFFVM

Lot no: V2-

36606

18-Jan-11

5-Mar-11

Store in a

cool dry

area.

Refrigerate

after

opening. Do

not freeze.

Edible vegetable oil,

water, sugar, milk

solids, lemon juice,

edible common salt,

permitted emulsifying

& stabilising agents

(E1442, E415),

permitted Acids

(E260, E330),

Permitted

Antioxidants (E319).

Contains permitted

class II Preservatives

(E211, E202)

Per 100 g: Energy:

564.7kcal, Protein:

1.2g, Fat: 59.1g,

Trans fats:0.0g,

Cholesterol: 0.0g,

CHO:6.9g, Sugar:

5.4g

Zero

cholesterol,

zero trans

fats, Mfd. In

ISO

22000:2005

certified

plant

Classic

Mayonnaise

Fun Foods

MSCFFCM

V2-378

8-Jan-11

5-Mar-11

Store in a

cool dry

area.

Refrigerate

after

opening. Do

not freeze.

Edible vegetable oil,

water, sugar, egg yolk,

milk solids, lemon

juice, edible common

salt, permitted

emulsifying &

stabilising agents

(E415, E440),

permitted Acids

(E260, E330),

Permitted

Antioxidants (E319).

Contains permitted

class II Preservatives

(E211, E202)

Per 100 g: Energy:

618.1kcal, Protein:

2.4g, Fat: 63.4g,

Trans fats:0.0g,

CHO:9.4g, Sugar:

5.6g

Zero trans

fats, Mfd. In

ISO

22000:2005

certified

plant

244

The fatty acid profile including TFA for all the 23 selected food samples have

been analysed using gas chromatography coupled with flame ionization detectors.

For the assessment of TFA content in food items, fat was extracted from the food

samples using soxhlet method. The individual food items were homogenized/

ground and an accurately weighed representative portion was taken for extraction.

These extracts of fats were then converted into their fatty acid methyl esters

(FAMEs) which were run in a chromatogram to identify the fatty acid (FA) peaks

against those of fatty acid standards.

The fatty acid profile of fried, baked, dairy food items and 2 samples of

mayonnaise (vegetarian and with egg) have been expressed as g/ 100g of the fat

extract. Further, the total amounts of total fat/ fatty acid per 100g of the food item

have also been estimated, from where the TFA content per serving of food item

have also been computed in order to have a clearer understanding and to see the

actual amount of fat, in particular the amount of trans fatty acid being consumed.

Where applicable, accurately measured weights, rounded to nearest whole number

(samosa, bread pakora, aloo tikki, aloo chaat, gulabjamun, bhatura, parantha,

bakery biscuit, rusk, patties, pastry, pizza, burger and cheese slice) or standard

serving sizes (potato chips, bhujia, French fries, milk, curds, cottage cheese,

mayonnaise, mayonnaise with egg) of the selected food samples have been taken

for calculating the values for one serving. The results of fried, baked, dairy food

items are being discussed separately.

4.II.3.1 Laboratory Analysed Fatty Acid Profile of Commercially Prepared

Fried Food Samples Selected for the Study

In all 10 fried food samples were selected for analysis. The complete fatty acid

profile (SFA, cis-MUFA, cis-PUFA, cis-TUFA and total TFA) was estimated for

all the food samples. The results have been expressed as g/ 100g of fat, g/ 100g of

food item and g/ serving of the food item.

The SFA content of these food items (g/ 100g of the extracted fat) ranged between

41.2g (aloo Tikki) to 64.8g (Gulabjamun); cis-MUFA 18.2g (French Fries) to

36.05g (Bhujia); cis-PUFA 10.0g (Gulabjamun) to 19.8g (French Fries) (Table

4.II.16). With respect to the total TFA content of the extracted fat samosa had the

245

highest content (8.1g/ 100g of extracted fat) while bread pakora had the lowest

levels of TFA (2.3g/ 100g of extracted fat). As far as TFA is concerned, there are

a number of factors which could have contributed towards the TFA content of the

food, like the type and quality of fat/ oil used for frying (use of partially

hydrogenated vegetable fat or re-used fat/ oil can lead to higher levels of TFA),

type of food being prepared and duration of frying (foods requiring quick frying

e.g. poori/ bhatura would lead to lesser generation of TFA as compared to food

items like samosa, mathri, bhujiya which require deep frying for longer duration

at varying temperature), duration of heating fat/ oil before frying, temperature at

which frying was done, number of frying cycles, type of fat/ oil used for

shortening in the food etc. Under the prevailing conditions, all these factors are

unknown, thus the TFA content could be due to summation of all these factors.

Table 4.II.16: Laboratory Analysed Fatty Acid Profile of the Fried Foods

Selected for the Study (g/100g of extracted fat)

Food

product Code SFA (g)

cis –

MUFA

(g)

cis –

PUFA

(g)

cis -

TUFA

(g)

Total

TFA

(g)

Potato Chips FFPCK 51.2 26.4 14.6 40.8 3.09

Bhujia FFBB 41.4 36.05 17.7 53.7 3.80

Bread pakora FBPR 48.2 35.7 13.5 49.2 2.30

Tikki FFTRV 41.2 31.4 18.8 50.2 6.10

Aaloo chat FFACRV 43.2 32.6 19.1 51.7 4.70

Samosa FFSS 45.8 30.7 15.5 46.0 8.10

French Fries FFFFB 55.6 18.2 19.8 38.0 6.40

Gulabjamun FFGJB 64.8 21.0 10.0 31.0 3.90

Bhatura FFBhEG 53.2 28.8 14.1 43.0 3.40

Paratha FFPR 43.1 35.02 17.3 52.3 4.70

246

A clearer picture emerged when the fatty acid profile of the selected foods was

expressed per 100g of food item (Table 4.II.17 and Figure 4.II.13); and as g/ per

serving of food item (Table 4.II.18). All these foods, being deep/ shallow fried

had high total fat content ranging between 41.0g/ 100g of food (potato chips) and

10.5g/ 100g of food (gulabjamun). These figures varied when the values were

computed for one serving of food, wherein the total fat content ranged between

7.8g/ serving of bhujiya and 38.0g/ serving of aloo chaat. However, it is to be

noted that one typical serving may vary from individual to individual, as some

people do not even eat one full serving while others consume much more than one

serving.

Bhujia is a commonly consumed tea time snack preferred mostly by

adults, women in particular, while potato chips although are common among

adults particularly office goers, are also the preferred choice of snack among

children and adolescents. Potato chips and bhujia when analysed for their fatty

acid profile including TFA, showed almost similar fatty acid profile per 100 g of

food item, with potato chips having a slightly higher total fat and SFA content

(41.0g and 21.0g) as compared to bhujia (38.9g and 16.1g). The values for cis-

MUFA was higher in bhujia (14.0g) as compared to potato chips (10.8g), while

the cis-PUFA content were almost similar (6.0g and 6.9 g respectively). Their

TFA content also varied slightly, with bhujia having a higher level (1.48g) as

compared to potato chips (1.27g). This could perhaps be due to the longer

duration of cooking required in case of bhujia as compared to potato chips. The

values for one serving of potato chips (35g; 1 small packet) had ≈ 14.4g of total

fat, 7.3g SFA, 3.8 g cis-MUFA, 2.1g cis-PUFA and 0.44g of TFA.

However, these values are bound to increase by double when a large packet (60g)

of chips is consumed. The values for one serving of bhujia has been calculated

for 20g (specified as 1 serving on packet labels) and for 50g (1 small packet,

which is easily consumed at a time). The value of TFA per 20g of serving (0.30g)

was similar to 35g serving of potato chips (0.44g), while that of 50g serving was

0.74g. The TFA content of bhujia as well as potatochips could perhaps be

attributed to the high temperature and duration of heat exposure subjected to the

oil.

247

Bread pakora is a favoured tea time snack specifically among school

teachers (subjects under study) and is easily available in school canteens. The

laboratory analysis of Bread pakora revealed that it had as much as 14.7g of

total fat/ 100g of food item, the value was almost similar (14.0g) when

calculated for one serving (95g). The SFA content per 100g of food was

estimated to be 7.1g, while it was 6.7g in one serving, while the TFA content

in 100g and one serving of bread pakora was 0.34g and 0.32g respectively.

Similar to bread pakora, samosa, is also one of the most common and

frequently consumed, deep fried tea time snack, having fat content equal to

almost three exchanges (15.8g/ 100g of food and 14.2g/ serving of food),

with almost half of it as SFA (7.2g/ 100g of food; 6.5g/ serving). It had

moderate levels of cis-MUFA (4.9g/ 100g of food; 4.4g/ serving) and cis-

PUFA (2.4g/ 100g of food; 2.2.g/ serving). However, the TFA content of

samosa came as a surprise to be as high as 1.28g/ 100g of food and 1.15g/

serving. Indicating that samosa can contribute to a large part of dietary TFA.

Unlike the bread pakora, the fat used for shortening in the crust (which

usually has to be a solid fat like desi ghee or vanaspati to provide appropriate

structure to the crust), sautéing of the filling as well as the temperature and

duration of frying could have together contributed to the TFA content of

samosa.

The fried aloo chaat a very common and popular street food, had

approximately four exchanges of fat per 100g (21.7g/ 100g) with high SFA

(9.4g/ 100g) and moderate levels of cis-MUFA (7.1g/ 100g) and cis-PUFA

(4.1g/ 100g). It had fairly high level of TFA, reaching out to 1.02g/ 100g.

These values increased further when the fatty acid profile was calculated for

one serving (1 plate) of aloo chaat which was 175 gram. Of main concern were

the total fat, SFA and TFA which were found to be reaching far end values of

38.0g, 16.4g and a whopping 1.78g per serving respectively. High TFA content

could possibly be due to the use of partially hydrogenated vegetable fat

(vanaspati) or due to the repeated use of used oil. However, since the food

samples were randomly picked from the market stores, no concrete reasoning

248

can be provided. French fries often referred to as western counterpart of aloo

chaat, and very much liked by the urban Indian population, was also analysed

for its fatty acid profile including total TFA content. The total fat content was

estimated to be almost equivalent to four exchanges of fat (19.9g/ 100g) with

more than half of it coming through SFA (11.1g/100g). Cis-MUFA and cis-

MUFA which were almost equal (3.6g/ 100g and 3.9g/ 100g respectively),

contributed to less than one-fourth of the total fat content. The total TFA

content (1.27g/ 100g) was quite high, similar to that of samosa. However, the

per serving (1 medium French fries; 110g) value of total TFA content was

slightly higher (1.47g/ serving). It was interesting to observe that the value of

total TFA, though was high in 100g French fries as compared to Fried aloo

chaat but the per serving value of total TFA was higher in the latter due to

larger serving size (1 plate;175g).

A similar picture emerged with aloo tikki wherein 100 grams of the food item

had 18.6g of total fat, 7.7g SFA, 5.8g cis-MUFA and 3.5g cis-PUFA. The value

of total TFA was comparable to that of fried aloo chaat, coming to nearly

1.13g/ 100g. The values for per serving (140g; 2 pieces) showed higher levels

of all the fats including total TFA which was 1.59 g. Both aloo tikki and fried

aloo chaat are shallow fried food items, using lot of fat/ oil on griddle (tawa)

and values of high TFA content could be due to the use of vanaspati either

alone or in blend with some other vegetable oil, moreover the fat/ oil being

repeatedly used several times as well as undergoing countless frying cycles

with intermittent episodes of heating and cooling, could further increase the

TFA content.

Gulabjamun on the other hand was detected to have approximately two

exchanges (10.5g) of fat per 100g, which was substantially less in comparison

to all other fried foods, the values slightly increased to less than three fat

exchanges (13.7g) when computed for one serving (2 pcs; 130g). The SFA

content was ≈ 6.8g/ 100g of food item, while cis-MUFA and cis-PUFA were

2.2g/ 100g of food item and 1.1g/ 100g of food item respectively. The total

TFA content was also less in comparison of other fried food items under study

249

(0.41g/ 100g of food item and 0.53g/ serving of food). The values increased

slightly when computed for one serving. However, due to its high sugar content

it cannot be considered as a healthier option. There is paucity of data on TFA

content of Indian sweets, however, the limited data available on the same

reveals that TFA content in Indian sweets (n=8) ranged between 6-28 per cent

of total fatty acids (Ghafoorunissa, 2008), while in the present study it was

noted to be quite low i.e. 3.90g/ 100g of fat extract.

Table 4.II.17: Fatty Acid Profile Fried Foods Selected for the Study

(g/100g food item)

Food product Code Total fat content

(g/ 100g)

SFA

(g/ 100g)

cis – MUFA

(g/ 100g)

cis – PUFA

(g/ 100g)

cis – TUFA

(g/ 100g)

Total

TFA

(g/ 100g)

Potato Chips FFPCK 41.0 21.0 10.8 6.0 16.7 1.27

Bhujia FFBB 38.9 16.1 14.0 6.9 20.9 1.48

Bread pakora FBPR 14.7 7.1 5.2 2.0 7.2 0.34

Tikki FFTRV 18.6 7.7 5.8 3.5 9.3 1.13

Aaloo chat FFACRV 21.7 9.4 7.1 4.1 11.2 1.02

Samosa FFSS 15.8 7.2 4.9 2.4 7.3 1.28

French Fries FFFFB 19.9 11.1 3.6 3.9 7.6 1.27

Gulab Jamun FFGJB 10.5 6.8 2.2 1.1 3.3 0.41

Bhatura FFBhEG 15.4 8.2 4.4 2.2 6.6 0.52

Parantha FFPR 14.9 6.4 5.2 2.6 7.8 0.70

Bhatura, which is a favourite Sunday breakfast dish among the urban north Indian

population consumed at both commercial eating outlets as well as prepared at

home was also analysed for its fatty acid profile. The analysis revealed that it

contains a massive 15.4g fat/ 100g of food with SFA comprising more than half

of it (8.2g). The cis-MUFA and cis-PUFA content were 4.4g and 2.2g/ 100g of

food respectively. The total TFA content which was detected to be 0.52g/ 100g

250

of food, increased remarkably to 1.05g when the values were computed for one

serving (2 pieces; 180g), indicating that even one plate of bhatura (2 pieces) is

sufficient to increase the dietary consumption of TFA.

Parantha which is consumed almost daily by a majority of the urban

population as well as subjects under study when evaluated for its fatty acid

profile revealed high amount of total fat (14.9g), SFA (6.4g) and total TFA

(0.70g) in 100g of food item. The values nearly doubled when computed

for 1 serving (2 pieces; 170g parantha) with TFA content reaching 1.11g/

serving of food item. There was no deep frying involved, even then a

number of factors could have contributed to the TFA content like type of

fat/ oil used for frying and for shortening and the temperature at which

shallow frying was done etc.

Figure 4.II.13: Fatty Acid Profile including TFA of select fried food items

0

5

10

15

20

25

30

35

40

45

g/

10

0g

fo

od

ite

m

Total fat SFA cis - MUFA cis - PUFA Total TFA

251

Table 4.II.18: Fatty Acid Profile Fried Foods Selected for the Study (g/

serving)

Food

product Code

Weight

(serving

size)

Total

fat

content

(g)

SFA

(g)

cis -

MUFA

(g)

cis -

PUFA

(g)

cis -

TUFA

(g)

Total

TFA (g)

Potato

Chips FFPCK

35 g

(1 small

Packet)

14.4 7.3 3.8 2.1 5.9 0.44

Bhujia FFBB 20 g 7.8 3.2 2.8 1.4 4.2 0.30

Bhujia FFBB 50 g(1 small

Packet) 19.5 8.1 7.0 3.4 10.4 0.74

Bread

pakora FBPR

95 g

(1 pc) 14.0 6.7 5.0 1.9 6.9 0.32

Tikki FFTRV 140 g

(2 pcs) 26.0 10.7 8.2 4.9 13.1 1.59

Aaloo chat FFACRV 175 g

(1 plate) 38.0 16.4 12.4 7.3 19.6 1.78

Samosa FFSS 85 g

(1 pc) 14.2 6.5 4.4 2.2 6.5 1.15

French

Fries FFFFB

110 g

(1 Medium

fries)

21.9 12.2 4.0 4.3 8.3 1.40

Gulabjamun FFGJB 130 g

(2 pcs) 13.7 8.8 2.9 1.4 4.2 0.53

Bhatura FFBhEG 180 g

(2 pcs) 30.8 16.4 8.9 4.3 13.2 1.05

Parantha FFPR 170 g

(2 pcs) 25.3 10.9 8.9 4.4 13.2 1.19

252

These results demonstrate that all the fried food items in the study had some

amount of TFA present in them, highlighting that consumption of even one of

these items on a daily basis (as reported in the present study) could significantly

contribute to the total TFA intake and hence the adverse health effects.

4.II.3.2 Laboratory Analysed Fatty Acid Profile of Commercially Prepared

Baked Food Items Selected for the Study

In all 6 bakery food samples were selected for analysis. The complete fatty acid

profile (SFA, cis-MUFA, cis-PUFA, cis-TUFA and TFA) was estimated for all

the food samples. The results have been expressed as gram/ 100gram of fat, gram/

100gram of food item and gram/ serving of food.

Table 4.II.19: Laboratory Analysed Fatty Acid Profile of the Baked Foods

Selected for the Study (g/100g fat)

Food product Code SFA cis -

MUFA

cis -

PUFA

cis -Total

unsaturated

fatty acid

Total

TFA

Bakery

Biscuits BFCR 46.5 36.3 9.2 45.5 5.60

Rusk BFRL 46.3 29.5 21.5 51 2.60

Patties BFPR 43.4 33.2 16.2 49.4 7.02

Pastry BFPS 55.2 24.8 7.8 32.6 6.10

Pizza BFPR 49.1 23.7 20.4 44.2 1.60

Burger BFBR 30.8 35.9 28.7 64.6 3.10

The SFA content in grams/ 100 grams of extracted fat of the selected baked food

samples ranged between 30.8g/ 100g of extracted fat (Burger) and 55.2g/ 100g of

253

extracted fat (Pastry), while the cis-MUFA and cis-PUFA content ranged between

23.7g/ 100g of extracted fat (Pizza) to 36.3g/ 100g of extracted fat (Bakery

Biscuits) and 7.8g/ 100g of extracted fat (Pastry) to 28.7g/ 100g of extracted fat

(Burger) respectively (Table 4.II.19). As far as total TFA content is concerned, it

ranged between 1.6g/ 100g of extracted fat (pizza) to 7.02g/ 100g of extracted fat

(Patties). Baked foods require hardened/ solid fat which can provide some texture

to the food items, the most common choice for this is butter, but owing to its high

cost, cheaper substitute like bakers shortening/ margarine are used. These

substitutes are hydrogenated fats and are thus high TFA content, leading to high

levels of TFA in bakery products. Although, in western countries trans-fat free

bakery fats are available, their availability in India is still a question. A better view

was visible when the fatty acid profile of the selected foods was expressed per

100g of food item (Table 4.II.20 and Figure 4.II.14); and as g/ per serving of food

item (Table 4.II.21).

Bakery biscuits which are quite commonly consumed among Indian households

were detected to have high levels of total fat (23.8g/ 100g of food) and SFA

(11.1g/ 100g of food), with total TFA being as high as 1.33g/ 100g of food. The

values though were high for 100g of food item diluted down to half when

calculated for one serving (2pcs; 50g). However, even then consuming just 2

pieces of bakery biscuits could contribute 0.67g of dietary TFA, mainly coming

from baker’s shortening or margarine (partially hydrogenated vegetable fats).

Consumption of high TFA containing foods can cause adverse health effects in the

longer run. The limited data available in Indian literature on TFA content of

various type of biscuits (n=14) purchased from local bakeries show that TFA

ranged between 30-40 per cent of total fatty acids (Ghafoorunissa, 2008),

however, in the present study it was estimated to be quite low i.e. 5.60g/ 100 g of

extracted fat.

Rusk, which were reported to be commonly consumed by a majority of the

population under study were detected to have nearly two exchanges of total fat

(11.3g), comparatively low levels of SFA (5.2g) and moderate levels of cis-

MUFA (3.3g) and cis-PUFA (2.4g) per 100g. The total TFA content was 0.29g/

254

100g. However, the levels dropped down when the values were computed for per

serving (2pcs- 40g; SFA; 2.1g, cis-MUFA; 1.3g, cis-PUFA; 1.0g and total TFA;

0.12g). It is to be noted that rusk is consumed almost daily by majority of the

subjects as an accompaniment with their morning/ evening tea and therefore even

with low levels of TFA could contribute towards TFA related adverse effects in

the longer run, unless trans fat free fat/ shortening is used.

Patties when tested for their fatty acid profile were found to have as high as

22.5g of total fat per 100g, equivalent to more than four exchanges of fat, with

almost half of it coming from SFA (9.8g/ 100g of food item). The cis-MUFA

and cis-PUFA content were detected to be 7.5g/ 100g of food item and 3.6g/

100g of food item respectively, the total TFA content was also quite high

reaching out to 1.58g/ 100g of food item. The values for per serving (1 pc; 85g)

were quite similar to that of 100g of food item (SFA-8.3g; cis-MUFA- 6.3g;

cis-PUFA; 3.1g; total TFA- 1.34g). Preparation of patties requires substantial

amount of solid fat, although butter is the recommended fat, it is rarely used

owing to its high cost, as a result cheaper fat substitutes like margarine and

baker’s shortening are used which lend desirable texture to the food, however,

these being hydrogenated contribute majorly towards its TFA content.

Pastry, another food item which is quite popular among the masses,

fondly consumed either as part of any celebration (birthday/ anniversary) or

otherwise, when tested for its fatty acid profile including TFA was detected to

have slightly more than three exchanges of total fat (16.4g/ 100g of food item),

mainly coming from SFA (9.1g/ 100g of food item), having comparatively

lesser amount of cis-MUFA (4.1g/ 100g of food item) and cis-PUFA (1.3g/

100g of food item), while total TFA was estimated to be 1.00g/ 100g of food

item. The per serving value calculated for 90g of the food item (1 piece) did not

show a major difference, with total TFA content being 0.90g/ serving of food

item. Although pastry is consumed only at special occasions however,

consuming nearly 0.90g of TFA in one single serving is way too high,

considering the adverse health effects associated with TFA.

255

Pizza, although has an Italian origin, has reached a high level of popularity in

urban India with people of all age groups liking it and reportedly consuming it at

different frequencies. There are different pizza combinations available to suit

individual needs varying in their crusts, texture, thickness, sizes and more

importantly toppings. In the present study a standard vegetarian pizza was

analysed for its fatty acid profile including TFA. The total fat content was

estimated to be ≈13.8g/ 100g of food item, exactly half of which was coming

from SFA (6.8g/ 100g of food item). The cis-MUFA (3.3g/ 100g of food item)

and cis-PUFA (2.8g/ 100g of food item) were almost equal and the total TFA

was estimated to be 0.22g/ 100g of food item. However, the serving size of

pizza varies with each individual, although the standard size is one slice (~70g),

a minimum of two to four pizza slices are consumed on an average. The fatty

acid profile increases with increase in serving size, with respect to total TFA

content the levels range between 0.15 g/ slice to 0.62g/ 4 slices. Although the

levels are much less as compared to other bakery food items, frequent

consumption can still contribute to the overall intake of total TFA.

Burger, another fast food coming from the western cuisine is quite popular

among the urban Indian population. It is available in different combinations and

sizes (with/ without cheese or mayonnaise) to suit individual taste; however, in

the present study a standard vegetarian burger (190g) was taken for assessment

of fatty acid profile including TFA. The total fat content was estimated to be

22.6g/ 100g of food item, ≈ four fat exchanges, while the SFA, cis-MUFA and

cis-PUFA content were 7.0g/ 100g of food item, 8.1g/ 100g of food item and

6.5g/ 100g of food item respectively. The total TFA content was detected at the

level of 0.70g/ 100g of food item. These values almost doubled when computed

for one serving of burger (190g) with total fat coming to be 42.9g and nearly

one-third of it coming from SFA (13.2g), while the total TFA content was as

high as 1.33g. With this high level of TFA provided in a single serving of

burger, frequently consuming it can definitely prove detrimental for the health.

256

Table 4.II.20: Fatty Acid Profile Baked Foods Selected for the Study

(g/100g food item)

Food product Code Total

Fat SFA

cis -

MUFA

cis -

PUFA

cis -

TUFA

Total

TFA

Bakery

Biscuits

BFCR 23.8 11.1 8.6 2.2 10.8 1.33

Rusk

BFRL 11.3 5.2 3.3 2.4 5.8 0.29

Patties

BFPR 22.5 9.8 7.5 3.6 11.1 1.58

Pastry

BFPS 16.4 9.1 4.1 1.3 5.3 1.00

Pizza

BFPR 13.8 6.8 3.3 2.8 6.1 0.22

Burger

BFBR 22.6 7.0 8.1 6.5 14.6 0.70

Figure 4.II.14: Fatty Acid Profile including TFA of select baked food items

0

5

10

15

20

25

Bakery

Biscuits

Rusk Patties Pastry Pizza Burger

g/

10

0g

food

ite

m

Total fat SFA cis - MUFA cis - PUFA Total TFA

257

Table 4.II.21: Fatty Acid Profile Baked Foods Selected for the Study (g/

serving)

Food

product Code

Amount per

Serving

(Serving size)

Total

Fat SFA

cis –

MUFA

cis -

PUFA

cis -

TUF

A

Total

TFA

Bakery

Biscuit BFCR

50 g

(2 pcs) 11.9 5.5 4.3 1.1 5.4 0.67

Rusk BFRL 40 g

(2 pcs) 4.5 2.1 1.3 1.0 2.3 0.12

Patties BFPR 85 g

(1 pc) 19.1 8.3 6.3 3.1 9.4 1.34

Pastry BFPS 90 g

(1 pc) 14.8 8.1 3.7 1.2 4.8 0.90

Pizza BFPR 70 g

(1 slice) 9.7 4.7 2.3 2.0 4.3 0.15

Pizza BFPR

280 g

(1 small

pizza; 4

slices)

38.6 19.0 9.2 7.9 17.1 0.62

Burger BFBR 190 g

(1 pc) 42.9 13.2 15.4 12.3 27.7 1.33

258

4.II.3.3 Laboratory Analysed Fatty Acid Profile of Commercially Available

Dairy Products and Other Food Items Selected for the Study

In all 5 samples of dairy products and 2 samples of mayonnaise (vegetarian and

with egg) were selected for analysis. The complete fatty acid profile (SFA, cis-

MUFA, cis-PUFA and TFA) was estimated for all the food samples. The results

have been expressed as g/ 100g of extracted fat, g/ 100g of food item and g/

serving of food.

The SFA content in g/ 100 g of the total fat of the select dairy products ranged

between 51.7g/ 100 g of the total fat (Full cream milk, curds and cheese slice) to

69.1g/ 100 g of the total fat (Cottage cheese), while the cis-MUFA and cis-PUFA

ranged between 7g/ 100 g of the total fat (Cream) to 34.1g/100 g of the total fat

(Curds) and 9.3g/ 100 g of the total fat (Curds) to 25.3g/ 100 g of the total fat

(cream) respectively (Table 4.II.22).

The total TFA content ranged between 0.79g/ 100 g of the total fat (Curds) to

1.6g/100 g of the total fat (Cheese Slice). Despite the fatty acid profile of both the

samples of mayonnaise (g/100g of extracted fat) being similar, mayonnaise with

egg had a slightly higher level of SFA (48.2g/ 100 g of the total fat) than

vegetarian mayonnaise (44.5g/ 100 g of the total fat). The levels for cis-MUFA

(35.2g/ 100 g of the total fat and 31.2g/ 100 g of the total fat), cis-PUFA (16.8g

and 15.8g) were almost similar for mayonnaise egg and vegetarian mayonnaise

respectively. However, the total TFA content varied with mayonnaise vegetarian

having a lower level (3.3g/ 100 g of the total fat) as compared to mayonnaise egg

(4.7g/ 100 g of the total fat).

A slightly different picture appeared when the fatty acid profile of the selected

foods was expressed per 100g of food item (Table 4.II.23 and Figure 4.II.15); and

as g/ per serving of food item (Table 4.II.24).

259

Table 4.II.22: Laboratory Analysed Fatty Acid Profile of Selected Dairy

Products and Other Food Items (g/100g fat)

Food product Code SFA cis -

MUFA

cis -

PUFA

cis -Total

unsaturated

fatty acid

Total

TFA

Dairy Foods

Milk full

cream DFDMSMFC 51.7 32.6 14.4 47.04 1.10

Curd DFMDC 51.7 34.1 13.2 47.43 0.79

Cottage cheese DFCCL 69.1 20.5 9.3 29.8 1.10

Cream DFCRA 66.5 7 25.3 32.4 1.20

Cheese slice DFBCS 51.7 33.9 12.8 46.7 1.60

Other Foods

Mayonnaise MSCFFVM 44.5 35.2 16.8 52.09 3.30

Mayonnaise

egg MSCFFCM 48.2 31.2 15.8 47.02 4.70

Full cream milk, when analysed for its fatty acid profile including TFA was

detected to have SFA ≈ 3.1g/ 100g of food item, while the values for cis-MUFA

and cis-PUFA were 2.0g/ 100g of food item and 0.9g/ 100g of food item

respectively. The total TFA content was 0.07 (almost negligible). The values

increase to more than double when computed for one serving (1 glass; 240g) with

TFA content ≈ 0.16g/ serving of food item and SFA content being 7.4g/ serving.

The complete fatty acid profile of curd revealed a more or less similar picture

just like milk. The SFA content was 2.3g/ 100g of the food item, while the cis-

MUFA, cis-PUFA and TFA were estimated to be 1.5g/ 100g of food item, 0.6g/

260

100g of food item, and 0.04g/ 100g of food item respectively. The values were

almost similar when computed for one serving of curd (1 katori; 125g).

Cottage cheese (paneer), which is one of the most favoured dairy products

and quite popular among all when assessed for its fatty acid profile revealed

SFA ≈16.2g/ 100g of food item, while the cis-MUFA, cis-PUFA and total TFA

were estimated to be 4.8g/ 100g of food item, 2.2g/ 100g of food item, and

0.26g/ 100g of food item respectively. These values reduced to one-third when

computed for one serving which was taken to be as ≈ 30g (one exchange),

however, the serving size may vary with the type of recipe for which it is used.

Cream, which is an integral part of various recipes including the favourite

dal makhani and fruit cream, when assessed for its fatty acid profile including

total TFA revealed high level of total fat (31.6g/ 100g of food item), majorly

coming through SFA (21.0g/ 100g of food item) and moderately low levels of

cis-MUFA (2.2g/ 100g of food item) as well as cis-PUFA (8.0g/ 100g of food

item). The total TFA content was estimated to be 0.38g/ 100g of food item.

These values however, diluted when computed for per serving which was taken

to be 1 tablespoon (15g).

Cheese slice which is an ingredient of choice (optional) in various food

items including burger, sandwiches, subway sandwiches etc., was also assessed

for its fatty acid profile. The total fat content was detected to be as high as

25.0g/ 100g of food item, with exactly half of it being contributed by SFA

(12.9g/ 100g of food item). The cis-MUFA and cis-PUFA were 8.5g/ 100g of

food item and 3.2g/ 100g of food item respectively. The total TFA was

estimated to be 0.40g/ 100 g of food item, which was highest among all the

dairy products included for laboratory analysis in the present study. However,

the values were much less when computed for one serving which was taken to

be one cheese slice (≈20g).

Apart from the above mentioned five dairy products, this section also includes two

samples of mayonnaise (mayonnaise vegetarian and mayonnaise with egg). These

261

have been included as they form the secret ingredient for burgers, sandwiches, roti

rolls, dips etc. The fatty acid profile of both the mayonnaise differed slightly in

their total fat content and SFA. Vegetarian mayonnaise had slightly lower levels

of total fat and SFA (59.1g/ 100 g of food item and 26.3g/ 100g of food item

respectively) as compared to the classic mayonnaise with egg (63.4g/ 100g of

food item and 30.6g/ 100g of food item respectively), while the cis-MUFA and

cis-PUFA levels were almost equal. The total TFA levels also differed with

vegetarian mayonnaise having 1.95g/ 100g of food item while classic mayonnaise

having 2.98g/ 100g of food item. The value for one serving was computed taking

one tablespoon (15g) as the serving size. The TFA content for one serving was

0.29g in vegetarian mayonnaise while it was 0.45g in mayonnaise with egg.

Table 4.II.23: Fatty Acid Profile of Selected Dairy and Other Food Items (g/

100 g of food item)

Food product Code Total

Fat

(g) SFA

cis -

MUFA cis -

PUFA

cis -Total

unsaturated

fatty acid

Total

TFA

Dairy Foods

Milk full

cream* DFDMSMFC 6.0 3.1 2.0 0.9 2.8 0.07

Curds* DFMDC 4.5 2.3 1.5 0.6 2.1 0.04

Cottage cheese DFCCL 23.4 16.2 4.8 2.2 7.0 0.26

Cream* DFCRA 31.6 21.0 2.2 8.0 10.2 0.38

Cheese Slice DFBCS 25 12.9 8.5 3.2 11.7 0.40

Other Foods

Mayonnaise MSCFFVM 59.1 26.3 20.8 9.9 30.7 1.95

Mayonnaise egg MSCFFCM 63.4 30.6 19.8 10.0 29.8 2.98

*The value of total fat content was taken from the nutrition label of the respective

food item, as they were directly converted to their FAMEs and made to run in GC.

262

Table 4.II.24: Fatty Acid Profile of Selected Dairy and Other Food Items (g/

serving of food item)

Food

product Code

Amount per

Serving (Serving Size)

Total

Fat SFA

cis -

MUFA cis -

PUFA

cis -Total

unsaturated

fatty acid

Total

TFA

Dairy Foods

Milk full

cream*

DFDMSMFC 240 ml (1

glass) 14.4 7.4 4.7 2.1 6.8 0.16

Curd*

DFMDC 125 g (1

Katori) 5.6 2.9 1.9 0.7 2.7 0.04

Cottage

cheese

DFCCL 30 g (1 pc) 7.0 4.9 1.44 0.7 2.1 0.08

Cream*

DFCRA 15 g (1Tbs) 4.7 3.15 0.33 1.2 1.5 0.06

Cheese

Slice

DFBCS 20 g (1 slice) 5.0 2.6 1.7 0.6 2.3 0.08

Other Foods

Mayonnaise

MSCFFVM 15 g (1Tbs) 8.9 3.9 3.1 1.5 4.6 0.29

Mayonnaise

egg

MSCFFCM 15 g (1Tbs) 9.51 4.6 3.0 1.5 4.5 0.45

*The value of total fat content was taken from the nutrition label of the respective

food item, as they were directly converted to their FAMEs and made to run in GC.

263

Figure 4.II.15: Fatty Acid Profile including total TFA of select dairy and

other food items

To minimise the intake of industrial trans fatty acids (I-TFA) some countries have

introduced labelling, while others have introduced legislative limits on the content

of industrial TFA in food. However, most countries still rely on food producers to

voluntarily reduce the industrial TFA content in food. In a study by Stender et al

(2012) to investigate the efficiency of these strategies in the Europe, it was noted

that the TFA content in three different products (biscuits, cakes and wafers)

bought in the six European countries in 2005 and 2009 were compared. The

highest industrial TFA contents (10-15 g) in 100 g of food item in 2005 were

found in Hungary, Poland and the Czech Republic (Eastern European countries).

In France, Germany and the United Kingdom (Western European countries), the

industrial TFA contents were lower but still with many above 2 g in 100 g of food

item. In 2009, even after biscuits, cakes and wafers in the three Eastern European

countries contained a smaller, but still substantial, amount of industrial TFA. In

contrast, the industrial TFA content in food items in the three Western European

countries was minimal (<1 g/ 100g of food item).

0

10

20

30

40

50

60

70

Milk full

cream

Curd Cottage

cheese

Cream Cheese Slice Mayonnaise

vegetarian

Mayonnaise

with egg

g/

10

0g

of

foo

d ite

m

Total fat SFA cis - MUFA cis - PUFA Total TFA

264

In the present study twenty three food samples were analyzed using gas

chromatography (GC) coupled with flame ionization detectors (FID) for their fatty

acid profile including total TFA. A substantial number of products particularly the

fried and baked food items, contained a total amount of trans fatty acid that was

much higher than the tolerable limit of 2% of total fats enforced in Denmark, the

only country in the world that has a legal limit for trans fatty acids. Hence, the

public health authorities in India should initiate the legal process to introduce a

trans fatty acid limit for Indian foods in order to reduce the incidence of non-

communicable diseases.

4.III COMPOSITE USE OF THE DATA FROM LABORATORY

ANALYSIS AND FIELD WORK

As discussed earlier, in the present study the preliminary field work data formed

the basis for laboratory analysis and the study results of the laboratory analysis

were used for calculating the dietary intake, particularly the dietary intake of trans

fatty acids.

4.III.1 Dietary Intake with Special reference to Trans fatty Acid

In the present study the dietary intake of the subjects was assessed by a two day

(one working and one non-working day) 24-hour dietary recall method

(Table.4.III.1). The per cent energy derived from protein, carbohydrates, total fat

and fatty acids (SFA, cis-MUFA, cis-PUFA, omega 3 fatty acids, omega 6 fatty

acid and total TFA) were also calculated for all the subjects. As already discussed,

nearly half of the subjects (53.0%) were vegetarians and majority of them were

consuming three main meals. The pattern of consumption of mid-meals/ snacks

revealed that ~50 per cent of the subjects were having two mid-meals/ snacks per

day (early morning tea and evening tea). The frequency of consuming outside

food varied from daily to once a month with almost one-fourth of the subjects

reportedly consuming outside food almost thrice a week. The nutrient profile of

the Indian population is distinctive and highly heterogeneous in its composition

and varied in intake. While there is a general preponderance of vegetarianism, as

is evident in the present study, variations in the carbohydrate, fat and fiber

intakelargely depend upon the geographical region and socio-demographic profile

of the individual.

265

Energy: Data indicate that the average energy intake among the study

population was 2135 ± 254 kcal/ d. the mean intake on the non-school day (2219

± 391 kcal/ d) was significantly higher (p<0.001) than that on the school day

(2052 ± 281 kcal/ d). Elaborate meals, specifically breakfasts (mostly including

parantha/ poori or pakora) coupled with eating out on weekends (non-working

day) could perhaps be the most probable reason for the increased calorie

consumption. Changes in dietary habits have been involved in increasing the

burden and vulnerability of Indians to CVD (Rastogi et al, 2004).

Protein: The average protein intake by the subjects was 61.9 ± 8.9 g/d.

Just like energy, protein intake was also significantly higher (p <0.001) on non-

working day (65.3 ± 13.1 g/d) as compared to the working day (58.4 ± 11.5 g/d).

Further, the average per cent energy derived from protein was 11.6 ± 0.8. It was

almost similar for working and non working days (11.4 ± 1.4% and 11.8 ± 0.8%

respectively). In the present study, most of the subjects were vegetarian thus

pulses and dairy products were the only major proteins sources.

Carbohydrate: Carbohydrates form a major source of energy, especially

in the typical Indian cereal-based diets. In the present study, the average

carbohydrate intake among the subjects was 304.2 ± 40.0 g/d. It was significantly

higher (p <0.001) on non-working day (316.7 ± 56.5 g/ day) as compared to

working day (291.7 ± 55.5 g/d). The average per cent energy derived from

carbohydrates was found to be ~ 57 per cent. The mean energy per cent of

carbohydrates for working day was 56.9 ± 7.7, while that for non-working day

was slightly higher (57.1 ± 4.0). A high intake of refined carbohydrate may lead

to hyperinsulinaemia, high serum TG, low HDL-c levels and is also associated

with insulin resistance. The consumption of large carbohydrate meals is very

common in Asian Indians, especially at dinner time. This permits

hyperinsulinaemia to occur, and also causes postprandial hyperglycaemia and

hypertriglyceridemia. Therefore, a rational strategy would be to distribute

carbohydrate evenly throughout the day, through three to five meals per/ d,

especially in patients with diabetes, so as to avoid high carbohydrate loading.

266

Total Dietary Fibre delays the intestinal transit of the food consumed, is

important for proper bowel function and to reduce occurrence of chronic

constipation, diverticular disease and haemorrhoids. It also helps to reduce

plasma cholesterol and has a protective role against colon cancer, coronary

heart diseases, diabetes and obesity. In the present study the average intake of

total dietary fibre was 41.45 ± 7.0g/d. The intake was lower on working day

(39.4 ± 10.9 g/ d) as compared to the non-working day (43.5 ± 9.0 g/d; p

<0.001). Evidence from epidemiological studies supports the beneficial effects

of high intakes of fruits and vegetables, with possible reductions of over 80

per cent in CHD, 70 per cent in stroke and 90 per cent in T2DM by following

Mediterranean diets, which are low in energy and high in fibre (Willett, 2006).

Total Fat: Since the 1930s, several studies have implicated high dietary

fat intake with the development of obesity and hyperglycaemia (Cornish et al,

2006). A high dietary intake of fat has been reported in Asian Indians (Misra

et al, 2009a). Fat consumption ranged from 13 to 59 g/d in different regions

and states in India. In the present study the mean total fat intake was 75.7 ±

13.1 g/d. The consumption was more on the non-working day (80.9 ± 17.2

g/d) as compared to the working day (72.1 ± 17.4 g/ d; p <0.001). Similarly,

the per cent energy derived from fats was lower on working day (31.6 ± 6.7)

as compared to non-working days (32.8 ± 3.7; p <0.001), with the average

being 32.2 ± 4.2 per cent, which is slightly higher than the recommendation of

30 per cent of energy derived from fats.

Saturated fatty Acid (SFA): Dietary saturated fat intake has been shown

to increase low-density lipoprotein (LDL) cholesterol, and therefore has been

associated with increased risk of cardiovascular diseases (Siri-Tarino, 2010).

This evidence, coupled with inferences from epidemiologic studies and clinical

trials, has led to longstanding public health recommendations for limiting

saturated fat intake as a means of preventing CVD. In the present study the

mean SFA intake was 27.4 ± 6.8 g/ d. The intake was more on the non-working

day (29.6 ± 8.7g/ d) as compared to the working day (25.2 ± 8.9g/ d; p <0.001).

Similarly, the per cent energy derived from saturated fats was higher on non-

267

working day (12.0 ± 2.2; p <0.05) as compared to the working day (11.1 ± 3.5),

with the average being 11.5 ± 2.1 per cent, which is higher than the

recommendation of 10 per cent energy coming from saturated fats. Higher SFA

intake has also been reported to be associated with worse global cognitive and

verbal memory trajectories (decline), whereas higher MUFA intake was related

to better trajectories (Okereke et al, 2012).

Mono Unsaturated fatty Acid (MUFA): Studies have shown that a

MUFA-enriched diet results in significant increases in insulin sensitivity with

modest total fat intake in healthy subjects (Vessby et al, 2001). Further, MUFA-

rich diets have reported to lower mean plasma glucose and plasma TG levels and

reduced insulin requirements in patients with T2DM. The increase in insulin

sensitivity induced by MUFA-rich diets may be due to their effect on gastric

emptying and increased basal glucose uptake (Garg, 1998). Overall, high-MUFA

diets have shown beneficial effects in T2DM, but their influence on insulin

resistance, although appearing beneficial, is still inconclusive. The MUFAs are

present in olive, mustard, almond, canola, groundnut etc. The mean MUFA

intake in the present study was 20.2 ± 4.6g/ d. As in case of total fat and SFA the

consumption was more on the non-working day (21.3 ± 5.5g/ d) as compared to

the working day (19.1 ± 6.9g/ d; p <0.05). However, the per cent energy derived

from fats was almost similar for working day (8.4 ± 2.8) as well as non-working

days (8.7 ± 1.5), with the average being 8.5 ± 1.6 per cent, which is lower than

the recommended 10-15 per cent energy to be derived from monounsaturated

fats.

Poly Unsaturated fatty Acid (PUFA): The polyunsaturated fatty acids

(PUFA), primarily linoleic acid (LA) (n-6) and alpha-linolenic acid (ALA) (n-3),

have structural and functional roles in all cells and are essential dietary

components (Misra et al, 2010). The data on the intake of PUFA ranged from 3.3

per cent (India) to 11.3 per cent (Taiwan), and varied between 4 per cent and 6 per

cent in other developing countries. In the present study the mean PUFA intake

was 22.3 ± 3.0 g/ d. The consumption was more on the non-working day (23.4 ±

3.3g/ d) as compared to the working day (21.2 ± 4.5g/ d; p<0.05). The per cent

268

energy derived from polyunsaturated fats was almost similar for working (9.3 ±

2.0) as well as non-working days (9.5 ± 1.1), with the average being 9.4 ± 1.11 per

cent.

Total Trans fatty Acid (TFA): TFA are known to increase LDL-c levels,

worsen insulin resistance, may influence systemic inflammation, adiposity and

contribute to the development of T2DM and CHD (Laake et al, 2012). Besides

these effects, trans fatty acids may also elevate levels of lipoprotein(a)

(Mozaffarian, 2006). This fact is critically important in Indians where one of the

highest levels of lipoprotein(a) has been recorded and correlated to CHD (Anand

et al, 1998). Till date trans fatty acids in Indian diets were thought to be derived

only from vanaspati, which is used as cooking medium in India with TFA

content as high as 53 per cent. However, the present study indicates that even

refined vegetable oils which were initially considered free of trans fats contain

TFA after heating/ re-heating at high temperatures. With widespread and

increasing use of vanaspati, intake of trans fatty acid is likely to increase further

in the Asian Indian population. This issue is of further concern, since trans fatty

acids adversely alter the uptake and metabolism of essential fatty acids to an

extent that their deficiency may manifest (Hill et al, 1979). This is particularly

true if the essential fatty acid intake is low, as in the sample of Asian Indians

studied by Misra et al (2001).

In developing countries, the major contribution (> 4 en %) to dietary TFA is due

to consumption of industrially produced deep-fried and baked foods (Khosla and

Hayes, 1996; Misra et al, 2010). The estimates of trans fatty acid intake in

developed countries range from 0.5 to 2.6% of energy (Lichtenstein, 2000). In a

study by Misra et al (2001) in urban slum population of North India, the

consumption of TFA particularly in men was greater than 1 en %, while in

women it was 0.75 en%. Further, TFA intake (en %) was 1.1 en%

amongadolescents and young adults in North India (Misra et al, 2009a).

In the present study, the mean total trans fatty acid intake was 4.91 ± 1.5g/ d.

The consumption was noted to be much higher on the non-working day (5.93 ±

1.9g/ d) as compared to the working day (3.89 ± 1.1g/ d). Similarly, the per cent

269

energy derived from total trans fats was much higher on non-working day (2.40

± 1.51) as compared to working days (1.71 ± 0.64), with the average being 2.06

± 0.58 per cent, which is much higher than the dietary recommendation by

WHO (< 1 per cent energy derived from total trans fats). The average intake of

TFA in the present study is comparable to the average intake by the US

population, where in consumption of approximately 5.3 g TFA per day (2.6% of

their total energy intake) has been reported (Castro et al, 2010). Studies have

suggested that an intake of above 5 g of TFA daily is associated with health risk

that can be eliminated more easily than many other diet-associated health risks

by reducing TFA intake (Stender et al, 2012).

ω-3 Fatty Acid: Evidence from experimental studies has indicated the beneficial

effect of long-chain n-3 PUFA (fish oils) over n-6 PUFA (safflower-seed oil) in

preventing insulin resistance (Giacco et al, 2007). The mean ω- 3 fatty acid

intake in the present study was 2.3 ± 0.9 g/ d. The consumption was almost

similar on working (2.1 ± 1.5g/d) and non-working day (2.4 ± 0.8g/ d). The

average per cent energy derived from ω- 3 fatty acid was 0.94 ± 0.4, with the

consumption being almost similar on both working and non-working day (0.92 ±

0.6 vs 0.97 ± 0.3), which is much less than the recommendation of 1-2 per cent

energy to be derived from ω- 3 fatty acid.

ω-6 Fatty Acid: The mean ω- 6 fatty acid intake was 19.3 ± 2.7g/ d. The

consumption was higher on non-working (20.1 ± 4.2g/d) than the working day

(18.4 ± 2.6g/d; p<0.05). However, the per cent energy derived from ω- 6 fatty

acid was similar for working (8.07 ± 1.9) and on non-working day (8.15 ± 0.8),

with the average being 8.11 ± 1.0 per cent, which is within the recommended

range of 5-8 per cent energy to be derived from ω- 6 fatty acid. The mean ω-6/

ω-3 ratio was 8.6 ± 1.7, which was almost similar for both working (8.8 ± 1.9)

and the non-working day (8.4 ± 2.6), which is within the recommended range of

5-10.

Dietary Cholesterol:Dietary cholesterol is present only in foods of animal origin

such as milk, meatand their products, but not in plant foods. Vegetable oils do not

contain cholesterol. Cholesterol is found in all body cells and plays a key role in

270

the formation of brain, nerve tissue and is a pre-cursor for some hormones and

vitamin D. It is synthesized in the body and hence it is not an essential dietary

component. High cholesterol consumption has been associated with cardio-

metabolic risk factors. The blood cholesterol-elevating effect of dietary saturated

fats increases, when cholesterol consumption is high. Therefore, cholesterol

intake should be maintained below 200 mg/day. In the present study the mean

cholesterol consumption was 106.0 ± 26.0 mg/ d. The consumption was

significantly much higher on non-working day as compared to the working day

(p<0.001).

The present study depicted higher consumption of most of the nutrients on non-

working days as compared to working days which as discussed earlier could

possibly be due to elaborate, fat rich meals along with the increase in eating out

trend in the urban population.

271

Table 4.III.1: Average Nutrient Intake by the Subjects on Working and Non-

working Days (N=402)

Nutrients

Working

(School) Day

Non-Working

(Non- School)

day p value

Average

Mean ± SD Mean ± SD Mean ± SD

Energy (kcal) 2051.7 ± 281.3 2219.3 ± 390.7 <0.001 2135.5 ± 254.3

Protein (g) 58.4 ± 11.5 65.3 ± 13.1 <0.001 61.9 ± 8.9

Protein en% 11.4 ± 1.4 11.8 ± 0.8 0.984 11.6 ± 0.8

Carbohydrate (g) 291.7 ± 55.5 316.7 ± 56.5 <0.001 304.2 ± 40.0

Carbohydrate en% 56.9 ± 7.7 57. 1 ± 4.0 0.867 57.0 ± 4.2

Total Fat (g) 72.1 ± 17.4 80.9 ± 17.2 <0.001 75.7 ± 13.1

Fat en% 31.6 ± 6.7 32.8 ± 3.7 <0.001 32.2 ± 4.2

SFA (g) 25.2 ± 8.9 29.6 ± 8.7 <0.001 27.4 ± 6.8

SFA en% 11.1 ± 3.5 12.0 ± 2.2 <0.05 11.5 ± 2.1

MUFA (g) 19.1 ± 6.9 21.3 ± 5.5 <0.05 20.2 ± 4.6

MUFA en% 8.4 ± 2.8 8.7 ± 1.5 0.086 8.5 ± 1.6

PUFA (g) 21.2 ± 4.5 23.4 ± 3.3 <0.05 22.3 ± 3.0

PUFA en% 9.3 ± 2.0 9.5 ± 1.1 0.995 9.4 ± 1.1

TFA (g) 3.89 ± 1.1 5.93 ± 1.9 <0.001 4.91 ± 1.5

TFA en% 1.71 ± 0.64 2.40 ± 1.51 <0.001 2.06 ± 0.58

ω 3 (g) 2.1 ± 1.5 2.4 ± 0.8 0.892 2.3 ± 0.9

ω 3 en% 0.92 ± 0.6 0.97 ± 0.3 0.781 0.94 ± 0.4

ω 6 (g) 18.4 ± 2.6 20.1 ± 4.2 <0.05 19.3 ± 2.7

ω 6 en% 8.07 ± 1.9 8.15 ± 0.8 0.992 8.11 ± 1.0

Cholesterol (mg) 97.4 ± 35.4 114.5 ± 34.0 <0.001 106.0 ± 26.0

Total Dietary Fiber

(g) 39.4 ± 10.9 43.5 ± 9.0 <0.001 41.45 ± 7.0

n6/n3 ratio 8.8 ± 1.9 8.4 ± 2.6 0.981 8.6 ± 1.7

272

4.III.2Anthropometric measurement The data on anthropometric measurements and body composition gathered for this

study included height, weight, waist circumference, hip circumference, body fat

percentage, fat mass, fat free mass, muscle mass,bone mass [as assessed using bio

impedance analysis (BIA) body composition analyser] and calculation of body

mass index (BMI) and waist hip ratio (WHR). The mean height of the subjects

was 156.6 ± 6.2 cm, ranging between 140 cm to 178 cm, while mean weight of the

subjects was 64.6 ± 9.4 kg, ranging between 41 to 101.5 kg. The mean BMI value

of the subjects was 26.4 ± 4.1 kg/m2 ranging from 15.8 to 44.5 kg/m

2. The mean

value for waist circumference, hip circumference and waist hip ratio was 89.0 ±

11.6 cm (range; 58 to 126 cm), 97.4 ± 10.0 cm (ranged from 74 to 137 cm) and

0.92 ± 0.8 (0.69 to 1.2) respectively. The mean body fat percentage was noted to

be 35.7 ± 9.84 % (ranging from 12.6% to 72.9%), while the mean value for fat

mass was found to be 28.1 ± 11.2 kg (ranging between 7.2 to 71.1kg). The mean

fat free mass, muscle mass and bone mass were 37.6 ± 9.0 kg, 37.8 ± 5.9 kg and

2.6 ± 1.9 kg respectively (Table 4.III.2).

Table 4.III.2 Anthropometric Measurements

Anthropometric Measurements Mean ± SD Range

Height (cm) 156.6 ± 6.2 140 - 178

Weight (kg) 64.6 ± 9.4 41 - 101.5

BMI (kg/m2) 26.4 ± 4.1 15.8 - 44.5

Waist Circumference (cm) 89.0 ± 11.6 58 – 126

Hip Circumference (cm) 97.4 ± 10.0 74 – 137

Waist Hip Ratio 0.92 ± 0.8 0.69 - 1.2

Body Fat (%) 35.7 ± 9.84 12.6 - 72.9

Fat Mass (kg) 28.1 ± 11.2 7.2 - 71.1

Fat Free Mass (kg) 37.6 ± 9.0 12.6 - 58.4

Muscle Mass (kg) 37.8 ± 5.9 12.4 - 55.4

Bone Mass (kg) 2.6 ± 1.9 1.2 - 3.4

Prevalence of obesity: Obesity has emerged as an important health problem

worldwide including the developing countries like India. Obesity, abdominal

obesity, and co-morbidities are increasingly prevalent among urban Indians (Misra

et al, 2009b). In the present study the prevalence of overweight and obesity on the

273

basis of BMI alone was 21.9 per cent (BMI ≥ 23 - < 25) and 56.0 per cent (BMI ≥

25) respectively. The prevalence of obesity in the present study was higher than

the prevalence reported by Bhardwaj et al (2011b) among 242 women (50.1%)

residing in New Delhi, as well as the prevalence of 45.9% reported in an urban

population of Chennai in South India (Deepa et al, 2007).

Apart from weight, regional fat distribution, particularly abdominal obesity, is

considered important for development of insulin resistance, the metabolic

syndrome and coronary heart disease (Bhardwaj et al 2011b). In the present study

prevalence of obesity according to waist circumference was 75.6 per cent (WC >

80 cm) which was higher to the obesity prevalence calculated by BMI (Table 4.

III.3). The prevalence on the basis of waist hip ratio was recorded as 71.9 per cent

(WHR ≥ 0.8). More than 80% of total body fat is distributed in the subcutaneous

adipose tissue (SCAT) and 10-20% within visceral/ intra-abdominal adipose tissue

(IAAT) in adults (Wang et al, 2005). The prevalence of obesity on the basis of per

cent body fat per cent came around 70.7 per cent (body fat% ≥ 30%). Asian

Indians exhibit unique features of obesity; excess body fat, abdominal adiposity,

increased SCAT, IAAT and deposition of fat in ectopic sites (liver, muscle etc),

that may be responsible for high tendency to develop insulin resistance and

dysmetabolic state (Misra et al, 2009b). This high prevalence of generalized

obesity (by measurement of BMI and per cent body fat) and abdominal obesity

(by measurement of WC) and dysmetabolic state in urban Indian women is a

cause for serious concern and need urgent public health intervention.

Table 4.III.3: Prevalence of Obesity in the Study Population (N=402)

Prevalence of Overweight and Obesity N (%)

BMI ≥ 23 - <25 kg/m2 88 (21.9)

BMI ≥ 25 kg/m2 225 (56.0)

WC > 80 cm 304 (75.6)

WHR ≥ 0.80 289 (71.9)

Body fat % ≥ 30 per cent 284 (70.7)

274

Figure 4.III.1: Prevalence of overweight, obesity and hypertension in the

study population (N=402)

4.III.3. Clinical Parameters

In the present study, data were gathered on pulse rate and blood pressure, in

addition self-reported data on family history of obesity, diabetes, hypertension and

heart disease were also gathered.

Pulse Rate: Pulse rate/ heart rate refers to the number of heart beats per

unit of time, typically expressed as beats per minute (bpm). It can vary as the

body's need to absorb oxygen and excrete carbon dioxide changes, such as during

exercise or sleep. The measurement of heart rate is used by medical professionals

to assist in the diagnosis and tracking of medical conditions. The average pulse

rate of the subjects was 78.6 ± 9.4 beats per minute, ranging between 60 bpm to

106 bpm (Table 4. III.4).

Blood pressure: The mean ± SD systolic and diastolic blood pressure was

127.7 ± 20.4 and 77.9 ± 17.9 ranging between 93 to 185 mmHg and 52 to 145

0

10

20

30

40

50

60

70

80

Overweight

(BMI ≥ 23 -

<25 kg/m2)

Obesity (BMI

≥ 25 kg/m2)

WC > 80 cm WHR ≥ 0.80 Body Fat %

(≥ 30 per cent)

Hypertension

(NCEP ATP

III)

Hypertension

(JNC VII )

21.9

56

75.6

71.9 70.7

37.8 36.1

Per c

en

t

275

mmHg respectively. The prevalence of hypertension was 36.1 per cent according

to the JNC VII criteria (SBP ≥ 140 and DBP ≥ 90 mmHg), while it was 37.8 per

cent according to the NCEP ATP III criteria (SBP ≥ 130 and DBP ≤ 85 mmHg)

respectively (Misra et al, 2009) JAPI. The prevalence of hypertension according

to the JNC VII criteria (36.1 per cent) in the present study is similar to the

prevalence (39.2%) among 35-70 year old Indian women (both urban and rural) in

a population based nationwide study by Gupta et al (2012). According to the

study significant determinants of hypertension include age, high dietary fat, low

fiber intake, truncal and generalized obesity and even urban residence (Gupta et

al, 2012). While in another study by Bhardwaj et al (2011b) the prevalence of

hypertension among 242 women staying in New Delhi was found to be 25.2%.

Table 4.III.4 Clinical Parameters and Prevalence of Hypertension among the

Study Subjects

Clinical Parameters Mean ± SD Range

Pulse Rate (bpm) 78.6 ± 9.4 60 – 106

Systolic Blood Pressure (mmHg) 127.7 ± 20.4 93 – 185

Diastolic Blood Pressure (mmHg) 77.9 ± 17.9 52 – 145

Prevalence of Hypertension N %

NCEP ATP III ≥ 130/ ≥ 85 mmHg 192 37.8

JNC VII guidelines ≥ 140/ ≥ 90 mmHg 152 36.1

- Family History: Data were also gathered from subjects regarding their family

history of diseases like heart disease, hypertension, diabetes and obesity. Family

history for any disease forms an important basis for assessing the future risk of

developing that particular disease in an individual. In the present study 37.8 per

cent subjects reported a positive family history of obesity, while 29.6 per cent

reported a family history of hypertension (Table 4. III.5). Family history of heart

disease was positive for more than half of the subjects (~52%) while that for

276

diabetes was positive for nearly one-fourth (24.6%) subjects. Studies have

shown that there is a strong positive relationship between a potent parental family

history of a particular disease and development of that disease in the offspring. In

view of the current results, which show a strong family history for all the

mentioned metabolic abnormalities it is important that the study subjects adapt to

a healthy lifestyle and work towards its prevention.

Table 4.III.5: Self Reported Data on Family History of Heart Disease,

Diabetes, Hypertension and Obesity among Subjects

Family History N (%)

Family history of Heart Disease 209 (52.0)

Family history of Hypertension 119 (29.6)

Family history of Diabetes 99 (24.6)

Family history of Obesity 152 (37.8)

4.III.4Biochemical Parameters

The present study included assessment of biochemical parameters like fasting

blood glucose, fasting serum insulin and complete lipid profile (total cholesterol,

serum triglycerides, low density lipoprotein cholesterol, high density lipoprotein

cholesterol and very low density lipoprotein cholesterol) in a sub sample of the

population (n=162). For the biochemical parameters, it was proposed to collect the

blood samples from one-third of the enrolled subjects (n=135) from 2 schools,

however, the targeted number could not be achieved, therefore one more school

(from the 6 schools selected) was approached for blood parameters. Thus, the final

sample for blood estimation is 162 subjects. Once the teacher expressed her

interest in participation in the study and provided written consent, the preliminary

survey questionnaire cum interview schedule was administered followed by

collection of blood samples.

The mean ± SD fasting blood glucose was 99.8 ± 24.1 mg/ dL, ranging from 52 to

181 mg/ dL (Table 4.). The mean ± SD fasting serum insulin level was 11.1 ± 6.6

μU/ mL, while the mean HOMA- IR level was 3.4 ± 2.2. The mean levels for total

277

cholesterol and serum triglycerides were 198.8 ± 46.5 and 147.5 ± 47.4

respectively. Subjects’ mean levels for LDL-c, HDL-c and VLDL-c were 98.7 ±

38.4 mg/dL, 46.6 ± 9.8 and 29.8 ± 10.5 respectively (Table 4.III.6).

Table 4.III.6: Biochemical Parameters of the Subjects under Study (n=162)

Biochemical Parameters Mean ± SD Range

Fasting Blood Glucose (mg/ dL) 99.8 ± 24.1 52.0 - 181.0

Fasting Serum Insulin (μU/mL) 11.1 ± 6.6 6.1 - 43.5

HOMA-IR 3.4 ± 2.2 0.9 - 12.6

Fasting Lipid Profile

Total Cholesterol 198.8 ± 46.5 104.0 - 293.7

Serum Triglyceride 147.5 ± 47.4 62.3 - 339.5

Low Density Lipoprotein Cholesterol 98.7 ± 38.4 43.8 - 203.8

High Density Lipoprotein Cholesterol 46.6 ± 9.8 20.2 - 68.9

Very Low Density Lipoprotein

Cholesterol 29.8 ± 10.5 12.5 - 67.9

Cardio-metabolic risk factors

In the present study an attempt was made to study the cardio-metabolic risk

factors like impaired fasting glucose, diabetes, hyperinsulinimia,

hypercholesterolemia, hypertriglyceridimia, high LDL-c levels, low HDL-c levels

and the metabolic syndrome in a sub sample of the population under study

(n=162). Although the sample size was small but it gave a sufficient idea of the

metabolic state in the study population. Around one-fourth of the subjects had

impaired fasting glucose (IFG; 24.7%) while almost 18.5 per cent of the subjects

were suffering from diabetes (Table 4.III.7). Asian Indians, as an ethnic group,

have an unusually high predisposition to develop type 2 diabetes mellitus (T2DM)

and CVD. During the previous three decades, the prevalence of T2DM has almost

278

doubled in India and currently there are an estimated 62.4 million people with

diabetes and 77.2 million with pre-diabetes in India (Anjana et al, 2011).

Insulin resistance refers to a state in which a given concentration of insulin

produces a less-than-expected biological effect. It is a forerunner of T2DM and

cardiovascular disease (CVD) (Bonora et al, 2002). In the present study the

prevalence of hyperinsulinimia (fasting serum insulin ≥ 10.4 μU/mL) was reported

in as high as 45.7 per cent subjects, while insulin resistance as detected by

HOMA-IR (HOMA-IR ≥ 2.29) was present in 51.9 per cent subjects. Insulin

resistance and clustering of other metabolic risk factors, seen frequently in Asian

Indians, may be principal contributory factors for high prevalence of T2DM (Goel

et al, 2009).

The prevalence of hypercholesterolemia was seen in 43.8 per cent subjects while

that of hypertriglyceridemia was 44.4 per cent. Nearly 59.9 per cent of the

subjects had high levels of LDL-c (≥ 100mg/dL) which was higher than that of

42.7 per cent reported among women in urban population of New Delhi

(Bhardwaj et al, 2011b). Of specific concern was the presence of low levels of

HDL-c in ~ 63.6 per cent subjects (Figure 4.III.2). It is understandable that with

such high prevalence of obesity and abdominal adiposity, co-morbid risk factors,

dysglycemia and dyslipidemia would be high.

The prevalence of the metabolic syndrome (MS), which is a clustering of risk

factors, is increasing among south Asian countries including India, leading to

increased morbidity and mortality due to T2DM and CVD. In the present study,

the prevalence of the MS was 43.8 per cent, which was comparable to that of 48.2

per cent reported among women inhabiting in and around Kolkata (Das et al,

2010). The increasing incidence of the metabolic syndrome among the Asian

Indians is a reason for concern if effective interventions are not applied (Misra

and Misra, 2003).

279

Table 4.III.7: Prevalence of Cardio-metabolic Risk Factors (n=162)

Cardiometabolic Risk Factors N (%)

Impaired Fasting Glucose (IFG) (≥ 100 - ≤ 125

mg/dL) 40 (24.7)

Diabetes (≥ 126 mg/dL) 30 (18.5)

Hyperinsulinimia (≥ 10.4 μU/mL) 74 (45.7)

Insulin Resistance (HOMA-IR; ≥ 2.29) 84 (51.9)

Hypercholesterolemia (≥ 200 mg/dL)

71 (43.8)

Hypertriglyceridimia (≥ 150 mg/dL) 72 (44.4)

High LDL-c (≥ 100 mg/dL) 97 (59.9)

Low HDL-c (≤ 50 mg/dL) 103 (63.6)

The Metabolic Syndrome 71 (43.8)

Figure 4.III.2: Prevalence of Cardio-metabolic risk factors in the study

population (n=162)

0

10

20

30

40

50

60

70

24.7

18.5

45.7

51.9

43.8 44.4

59.9

63.6

43.8

Per cen

t

280

4.III.5Dietary TFA Intake vis Cardio-metabolic Risk Factors:

Anthropometry, Body Composition, Clinical and Biochemical

Parameters

There is an increased prevalence of lifestyle related non communicable diseases

among Indians. These have been linked with several risk factors including high

intake of total trans fatty acids (Mozaffarian et al, 2006). Adverse effects of

chronic high intake of trans fatty acids has not been studied extensively in Indians,

particularly in reference to urban population undergoing rapid lifestyle changes.

As described earlier, in the present study the preliminary data from field work had

served as the basis for initiating and carrying out the laboratory analysis, while the

result outcomes of the laboratory analysis have been used to compute the dietary

intake of subjects under study and understanding the adverse effects of TFA

intake on their health status. Thus, in the present study an attempt has been made

to explore the effect of trans fatty acid intake with cardio-metabolic risk factors

viz, anthropometry, body composition, clinical and biochemical parameters and

search for a possible association.

Grouping of the subjects as per their TFA intake

In the present study, the mean total trans fatty acid intake was 4.91 ± 1.5g/ d and

the average per cent energy derived from total trans fats was 2.06 ± 0.58 per cent,

which is much higher than the WHO recommendation (TFA< 1 en%). To have a

deeper understanding and to arrive at proper conclusions, the subjects under study,

based on their total TFA intake (expressed as en %) have been divided in three

groups; TFA intake less than 1 en% (group 1), between 1 - 2 en% (group 2) and

more than 2 en% (group 3). In the present study, very few subjects reportedly had

TFA intake less than 1 en% (Group 1; n= 48), while the remaining had a TFA

intake either between 1 to 2 en% (Group 2; n=187) or more than 2 en% (Group 3;

n=167). These groupings were used as the basis for understanding the association

between total TFA intake and anthropometric, body composition, clinical and

biochemical parameters affecting the cardio-metabolic risk profile.

281

Intergroup differences (based on total TFA intake) in anthropometry,

body composition, clinical and biochemical parameters

A one-way ANOVA followed by Scheffe’s test was conducted to compare the

effects of total TFA intake on the mean values of anthropometric

measurements, body composition, clinical and biochemical parameters for

each of these groups. The results indicated that the mean values of weight

(p<0.01), BMI (p<0.05) and body fat per cent (p<0.05) were significantly

higher in group 2 (TFA intake between 1-2 en%) and group 3 (TFA intake >2

en%) as compared to group 1 (TFA intake <1 en%), indicative of a positive

association between total TFA intake and these parameters. When intergroup

comparison was made using Scheffe’s test it was noted that the mean value for

weight was significantly higher (p<0.05) in group 3 as compared to group 1,

while mean value for BMI was higher in both group 2 (p<0.05) and group 3

(p<0.01) as compared to group 1. Further, the mean values of these parameters

although were more in group 3 as compared to group 2 but the difference was

not statistically significant.

The mean values of other anthropometric and clinical parameters like waist

circumference (p=1.129), hip circumference (p=0.277) and diastolic blood

pressure (p=0.411) although were higher in group 3 and group 2 as compared

to group 1, these were not found to be statistically significant. However, with

respect to pulse rate and systolic blood pressure, the mean values between the

three groups did not show any significant difference (Table 4.III.8).

Similar to weight, BMI and body fat per cent, the mean values of almost all

the biochemical parameters including fasting blood glucose (p < 0.001),

fasting serum insulin (p < 0.001), HOMA-IR (p < 0.001), total cholesterol (p <

0.001), serum triglyceride (p < 0.001), LDL-c (p<0.001) and VLDL-c

(p<0.05) were significantly higher in both group 2 and 3 as compared to group

1.

Further, when intergroup comparison was made using Scheffe’s test it was

noted that the mean value for fasting blood glucose (p < 0.001), fasting serum

insulin (p<0.001), HOMA-IR (p < 0.001), total cholesterol (p < 0.001), serum

282

triglyceride (p<0.001), LDL-c (p<0.001) and VLDL-c (p<0.05) were

significantly higher in group 3 as compared to group 1. Even compared to

group 2 the mean values of fasting blood glucose (p<0.001), fasting serum

insulin (p<0.001), HOMA IR (p<0.001), and total cholesterol (p<0.05) were

significantly higher in group 3, indicating that even a slight increase in the

total TFA intake could possibly have a negative effect on these parameters.

However, in the present study the mean value of HDL-c did not depict any

significant change among the three groups. Further, the role of other

confounding factors cannot be ruled out (Table 4.III.9).

Intergroup (based on total TFA intake) differences in prevalence of

cardio-metabolic risk factors

The test of association (Chi-square and Exact test) between the prevalence of

cardio-metabolic risk factors among the three groups based on the dietary

intake of total TFA indicated that there were statistical differences between

various levels of TFA intake.

Further, the prevalence of overweight, obesity (BMI > 25 kg/m2;

waistcircumference > 80 cm; WHR > 0.8), impaired fasting glucose, type 2

diabetes mellitus, insulin resistance, hyperinsulinemia, hypertriglyceridemia,

hypercholesterolemia, high levels of LDL-c and the metabolic syndrome

increased with the level of TFA intake (Table 4.III.10).

However, statistically significant difference were present only for the

prevalence of overweight (p< 0.01), Obesity (BMI ≥ 25 kg/m2; p<0.01 and

WC > 80cm: p<0.05), impaired fasting glucose (p < 0.001), T2DM (p<0.001),

insulin resistance (p<0.001), hyperinsulinemia (p<0.001),

hypertriglyceridemia (p<0.001), hypercholesterolemia (p<0.001), high levels

of LDL-c (p<0.001) and the metabolic syndrome (p<0.001). Further, no such

trend was visible in the case hypertension and low levels of HDL-c levels.

283

Table 4.III.8: Distribution of subjects by total TFA intake and

Anthropometry/ Body Composition/ Clinical parameters(N=402)

Anthropometry,

Body

Composition,

Clinical

Parameters

Anthropometry, Body Composition,

Clinical Parameters vis Total TFA

Intake F

value*

p value

< 1.0 en%

(Group 1;

n=48)

1.0 to 2.0

en%

(Group 2;

n=187)

> 2.0 en%

(Group 3;

n=167) Overall*

Group

1 Vs 2#

Group

1 Vs 3#

Group

2 Vs 3#

Weight (kg)

62.0 ± 8.1 65.5 ± 10.0 66.9 ± 10.4 4.48 <0.01 0.096 <0.05 0.438

BMI (kg/m2) 24.6 ± 3.1 26.2 ± 4.2 26.9 ± 4.0 6.13 <0.05 0.050 <0.01 0.250

WC (cm) 85.7 ± 10.4 87.8 ± 11.9 89.3 ± 4.0 2.06 1.129 0.530 0.157 0.460

HC (cm) 96.2 ± 10.1 96.3 ± 9.6 97.8 ± 9.6 1.29 0.277 0.994 0.561 0.332

Body Fat % 33.1 ± 8.4 34.9 ± 9.1 36.7 ± 9.6 3.40 < 0.05 0.532 0.066 0.170

Pulse 81.5 ± 9.8 82.2 ± 9.3 81.1 ± 9.3 0.62 0.536 0.912 0.956 0.538

SBP (mmHg) 130.1 ± 22.1 124.8 ± 19.9 130.2 ± 20.3 3.44 0.05 0.236 0.999 0.047

DBP (mmHg) 75.7 ± 16.5 77.3 ± 15.9 79.2 ± 20.4 0.89 0.411 0.862 0.498 0.613

* ANOVA; # Scheffe’s test

284

Table 4.III.9: Distribution of the subjects by total TFA intake and

Biochemical parameters

Biochemical

Parameters

Biochemical parameters visTotal

TFA Intake F

value*

p value

< 1.0 en%

(Group 1;

n=48)

1.0 to 2.0 en%

(Group 2;

n=187)

> 2.0 en%

(Group 3;

n=167) Overall*

Group

1 Vs

2#

Group

1 Vs 3#

Group

2 Vs 3#

FBG (mg/ dL)

90.3 ± 9.5 93.5 ± 21.2 112.4 ± 25.7 15.84 < 0.001 0.835 < 0.001 < 0.001

Fasting

Serum

Insulin (μU/ mL)

9.8 ± 1.5 12.2 ± 3.9 17.9 ± 7.7 43.45 < 0.001 0.958 < 0.001 < 0.001

HOMA-IR 2.1 ± 0.3 2.3 ± 0.8 5.0 ± 2.6 46.80 < 0.001 0.937 < 0.001 < 0.001

Total

Cholesterol

(mg/dL) 163.7 ± 28.2 195.7 ± 44.8 214.6 ± 46.7 11.88 < 0.001 <0.05 < 0.001 0.043

Triglyceride

(mg/dL) 113.5 ± 32.3 144.5 ± 47.8 162.5 ± 46.1 10.44 < 0.001 <0.05 < 0.001 0.065

HDL-c (mg/ dL)

46.2 ± 8.2 48.2 ± 10.6 44.8 ± 9.2 2.07 0.13 0.703 0.840 0.132

LDL-c (mg/ dL)

93.4 ± 22.6 119.3 ± 38.0 130.9 ± 39.1 8.96 < 0.001 <0.05 < 0.001 0.180

VLDL-c (mg/ dL)

24.2 ± 7.6 29.8 ± 10.4 31.7 ± 10.9 4.56 <0.05 0.077 <0.05 0.553

* ANOVA; # Scheffe’s test

285

Table 4.III.10 Distribution of thesubjects by total TFA intake and prevalence

of Cardio-metabolic risk factors

Cardio-metabolic risk factors Prevalence of Cardio-metabolic risk factor

visTotal TFA Intake p value

Anthropometry, Body

composition and Clinical

Parameters

(N=402)

< 1.0 en%

Group 1; n=48

(%)

1.0 to 2.0 en%

Group 2; n=187

(%)

> 2.0 en%

Group 3;

n=167 (%)

Overweight * 19 (39.6) 34 (18.2) 35 (21.0) <0.01

Obesity* 15 (31.3) 108 (57.8) 102 (61.1) <0.01

Waist Circumference> 80 cm* 31 (64.6) 138 (73.8) 135 (80.8) 0.05

Waist Hip Ratio > 0.80* 33 (68.8) 132 (70.6) 124 (74.3) 0.653

Hypertension (NCEP ATP III

criteria; ≥ 130/ ≥ 85 mmHg)* 18 (37.5) 60 (32.1) 67 (40.1) 0.284

Hypertension (JNC VII

guidelines; ≥ 140/ ≥ 90

mmHg)* 20 (41.7) 64 (34.2) 68 (40.7) 0.384

Biochemical Parameters

(n=162)

< 1.0 en%

Group 1;

n=32(%)

1.0 to 2.0 en%

Group 2;

n=69(%)

> 2.0 en%

Group 3;

n=61(%)

p value

Impaired Fasting Glucose

(FBG ≥ 100 - ≤ 125 mg/dL)# 3 (9.4) 12 (17.4) 25 (41.0) <0.001

Diabetes (FBG ≥ 126 mg/dL)# 0 (0.0) 6 (8.7) 24 (39.3) <0.001

Hyperinsulinimia (≥ 10.4

μU/mL) 6 (18.8) 20 (29.0) 48 (78.7) <0.001

Insulin Resistance (HOMA-IR;

≥ 2.29) 8 (25.0) 22 (31.9) 54 (88.5) <0.001

Hypertriglyceridimia (≥ 150

mg/dL)# 2 (6.3) 30 (43.5) 40 (65.6) <0.001

Hypercholesterolemia (≥ 200

mg/dL)# 1 (3.1) 26 (37.7) 44 (72.1) <0.001

High LDL-c (≥ 100 mg/dL) 5 (15.6) 42 (60.9) 50 (82.0) <0.001

Low HDL-c (≤ 50 mg/dL) 7 (21.9) 32 (46.4) 20 (32.8) 0.206

The Metabolic Syndrome# 3 (9.4) 27 (39.1) 41 (67.2) <0.001

*Chi-square test; # Exact test

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Multivariate linear regression analysis: association of TFA intake with

anthropometry, body composition, clinical and biochemical

parameters

Although it is a cross-sectional study, an attempt has been made to study the

association of total TFA intake with cardio-metabolic risk factors viz

anthropometry, body composition, clinical and biochemical parameters. Since a

number of factors can affect the cardio-metabolic risk profile, multiple linear

regression analysis was carried out to determine the possible role of TFA intake

of the subjects and other influential factors affecting the cardio-metabolic risk

factors viz anthropometry, body composition, clinical and biochemical

parameters.

Studies have demonstrated a significant association between TFA consumption

and body weight as well as obesity. Study by Field et al (2007) carried out on

more than 41000 women who provided two measurements of weight over 8 years

demonstrated that increases in TFA consumption were robustly associated with

increase in body weight in both cross-sectional and longitudinal analysis, after

adjustment for other risk factors. In the present study, the results of the multiple

linear regression analysis indicated that among subjects with TFA intake more

than 2 en%, the mean body weight was 3.18 kg higher (p<0.05) as compared to

the mean body weight of subjects with TFA intake less than 1 en% (R2=0.29).

Other factors including age, intake of total fat, PUFA and protein emerged out to

be significant ones (Table 4.III.11) other variables included in the model were

intake of energy, carbohydrate, MUFA, SFA, cholesterol and total dietary fibre.

Similar results were noted in the case of BMI indicating that mean BMI was 2.38

kg/m2 higher (p=0.001) in subjects with TFA intake more than 2 en% as compared

to subjects with TFA intake less than 1 en% (R2=0.31). Other factors which were

noted to significantly influence BMI were age, intake of total fat, PUFA and

protein. Other confounding variables included on the model were intake of

energy, carbohydrate, SFA, MUFA, n-6 fatty acid, cholesterol and total dietary

fibre). This clearly indicated the effect of TFA intake more than 2 en% on body

weight as well as BMI. However, no significant association was noted for body

weight and BMI in subjects with TFA intake between 1-2 en%.

287

Studies have suggested that total intake of trans fatty acids is a risk factor for gain

in waist circumference (Hansen et al, 2012), however, in the present study no

significant increase was visible for waist circumference and body fat per cent

among subjects with increase in total TFA intake when adjusted for confounding

factors.

Table 4.III.11: Multivariate linear regression analysis to determine the

association of total TFA intake with body weight, after adjusting for other

factors

Factors

Coefficient

Std.

Error

t

p

value

95% Confidence

Interval

Lower

value

Upper

value

TFA intake >

2en% 3.18 1.04 2.1 0.036 0.139 4.214

Total Fat intake 1.91 0.38 1.8 0.041 0.0391 2.468

PUFA intake 0.54 0.09 5.72 0.000 0.352 0.722

Protein intake -0.14 0.06 -2.21 0.028 -0.27 -0.020

Age 0.15 0.06 2.71 0.007 0.041 0.261

R2 = 0.29; In this model TFA intake < 1 en% was taken as the basis

Table 4.III.12: Multivariate linear regression analysis to determine the

association of total TFA intake with BMI, after adjusting for other factors

Factors Coefficient

Std.

Error t

p

value

95% Confidence

Interval

Lower

value

Upper

value

TFA intake

>2en% 2.38 0.40 3.41 0.001 0.583 5.169

Total Fat intake 0.98 0.04 2.19 0.029 0.009 1.175

PUFA intake 0.33 0.06 5.92 0.000 0.223 0.444

Protein intake -0.05 0.02 -2.39 0.017 -0.089 -0.009

Age 0.56 0.02 2.82 0.005 0.018 1.102

R2 = 0.31; In this model TFA intake < 1 en% was taken as the basis

Dietary TFA intake has been associated with dyslipidaemia and an increased risk

of T2DM and CVD (Salmeron et al, 2001; Misra et al, 2009a). In a study among

middle-aged and older Chinese individuals higher trans-18:1 levels were

associated with a lower risk of type 2 diabetes mellitus, whereas higher trans-18:2

levels were associated with dyslipidaemia (Yu et al, 2012). However, in another

288

cross-sectional study in Spanish population, TFA intake was not found to be

associated with the risk of type 2 diabetes mellitus (Papantoniou et al, 2010). In

the present study multiple linear regression analysis indicated that among the

subjects with TFA intake more than 2 en%, the mean fasting blood glucose levels

were 14.47 mg/dL higher (p< 0.001) as compared to subjects with TFA intake

less than 1 en%(R2=0.36). Other factors which were noted to significantly affect

fasting blood glucose levels were body weight, intake of energy, total fat, PUFA

and protein (Table 4.III.13). However, no association was observed between mean

fasting blood glucose levels and TFA intake between 1-2 en%, when compared to

subjects with TFA intake less than 1 en%, indicating that a TFA intake of more

than 2 en% has a higher degree of adverse effect on the fasting blood glucose

levels.

Table 4.III.13: Multivariate linear regression analysis to determine the

association of total TFA intake with fasting blood glucose, after adjusting for

other factors

Factors

Coefficient

Std.

Error

t

p

value

95% Confidence

Interval

Lower

level

Upper

level

TFA intake >

2en% 14.47 3.49 5.58 0.000 12.580 21.368

Energy intake 2.02 0.01 1.77 0.048 -0.002 4.036

Total Fat intake 1.97 0.45 2.15 0.033 0.079 2.862

PUFA intake -1.21 0.44

-

2.76 0.006 -2.077 -0.346

Protein intake -0.44 0.26 -1.7 0.092 -0.944 0.071

Weight 1.03 0.01 2.68 0.008 0.007 2.047

R2 = 0.36; In this model TFA intake < 1 en% was taken as the basis

Studies have shown that insulin resistance is initiated in adipose tissue which in

turn affects insulin sensitivity of skeletal muscle and liver (Micha et al, 2009).

TFA have shown to increase insulin resistance and seem to have a unique cardio-

metabolic imprint that is linked to insulin-resistance and metabolic-syndrome

pathways (Bhardwaj et al, 2011a). In the present study, multiple linear regression

analysis indicated that among the subjects with TFA intake more than 2 en%, the

mean fasting serum insulin levels were 3.12 μU/mL higher (p< 0.01) as compared

to subjects with TFA intake less than 1 en%(R2=0.45) when adjusted for

confounding factors. Other factors significantly affecting fasting serum insulin

289

included age, body weight, intake of SFA and PUFA (Table 4.III.14). Research

studies in patients with T2DM have shown an elevated postprandial insulin

response with a TFA-rich diet as compared with a cis-MUFA-rich diet. However,

data regarding the dietary influence of TFA on insulin resistance in healthy

subjects are limited (Christiansen et al, 1997). Studies have also speculated that

TFA interferes predominantly with insulin signaling via intracellular kinases,

which alter insulin receptor substrates. A study on exploring the effects of diets

enriched in various fatty acids on postprandial insulinemia and fasting serum

levels of lipids and lipoproteins indicated that both dietary TFA and SFA induce

an increase in postprandial insulinemia in obese patients with type 2 diabetes

mellitus (Christiansen et al, 1997). In another study by Angelieri et al (2012) on

127 non-diabetic Brazilian individuals, TFA intake was positively correlated with

HOMA-IR.

The results of the present study indicate that the mean HOMA-IR were 1.61 units

higher (p<0.001) in subjects with TFA intake more than 2 en% as compared to

subjects with TFA intake less than 1 en% (R2=0.47). Other factors significantly

affecting the levels of HOMA-IR were body weight, intake of SFA and PUFA

(Table 4.III.15).

Table 4.III.14: Multivariate linear regression analysis to determine the

association of TFA intake with fasting serum insulin, after adjusting for other

factors

Factors Coefficient

Std.

Error

t

p

value

95% Confidence

Interval

Lower

level

Upper

level

TFA intake >

2en% 3.12 0.70 4.48 0.003 1.743 4.490

SFA intake 0.15 0.05 3.03 0.003 0.054 0.255

PUFA intake 0.31 0.09 3.56 0 0.139 0.485

Age 0.09 0.04 2.28 0.024 0.012 0.162

Body weight 1.11 0.23 3.55 0.001 0.047 2.164

R2 = 0.45; In this model TFA intake < 1 en% was taken as the basis

290

Table 4.III.15: Multivariate linear regression analysis to determine the

association of TFA intake with HOMA-IR, after adjusting for other factors

Factors

Coefficient

Std.

Error

t

p

value

95% Confidence

Interval

Lower

level

Upper

level

TFA intake

>2en% 1.61 0.24 6.75 0.000 1.137 2.077

SFA intake 0.49 0.02 2.89 0.004 0.015 0.818

PUFA intake 0.60 0.03 1.98 0.049 0.025 0.919

Body weight 0.27 0.01 2.68 0.008 0.007 0.472

R2 = 0.47; In this model TFA intake < 1 en% was taken as the basis

The deleterious role of saturated and trans fatty acids in glucose and lipid

metabolism has been consistently demonstrated (Kennedy et al, 2009). Several

studies have revealed that a high intake of TFA is associated with an increased

risk of coronary heart disease (Karbowska and Kochan, 2011).

Dietary TFA has shown to promote inflammation and increase the levels of

markers of inflammation, e.g. tumor necrosis factor-α, interleukin-6, C-reactive

protein and endothelial dysfunction. TFA also raise plasma total cholesterol, low-

density lipoprotein-cholesterol and triglyceride, which are risk factors of

cardiovascular diseases (CVD), while these lower the level of cardio-protective

HDL-c in plasma (Glew et al, 2010). However, the results on this are not always

conclusive, in a study among young Japanese women, the mean intakes

of total and diene TFA (0.36 en% and 0.05 en% respectively) were not found to

have any significant correlation with total, LDL or HDL cholesterol levels

(Takeuchi et al, 2012). While, in another study by Sartika (2011b) among

Indonesian adults revealed that mean intake of trans fatty acids as low as 0.48% of

total calories (urban 0.40% and rural 0.55%) showed a statistically significant

relationship between TFA intake and hypercholesterolemia and

hypertriglyceridemia.

291

In the present study, multiple linear regression analysis indicated that mean total

cholesterol levels were 9.64 mg/dL higher (p<0.01) among subjects with TFA

intake more than 2 en% as compared to subjects with TFA intake less than 1 en%

(R2= 0.32), after adjusting for confounding factors (Table 4.III.16). Other factors

significantly affecting cholesterol levels were body weight, total fat intake and

PUFA intake.

Similarly the mean LDL-c levels were also 11.8 mg/ dL higher (p<0.01) among

subjects consuming TFA more than 2 en% as compared to subjects consuming

TFA less than 1 en% (R2=0.39),after adjusting for confounding factors (Table

4.III.17). Other factors significantly affecting LDL-c were body weight, intake of

total fat, PUFA and n-6 fatty acids.Whereas, no association was noted in the levels

of these parameters with TFA intake between 1-2 en%, indicating that TFA intake

more than 2 en% can have a deleterious effect on the cardio-metabolic health of

the population.

TFA consumption has been implicated as an independent risk factor for sudden

cardiac arrest. However, in the present study no significant association could be

noted between intake of TFA and systolic and diastolic blood pressure, serum

triglycerides, VLDL-c and HDL-c levels which point towards the role of other

confounding factors. Data on physical activity pattern should have also been

gathered to have a deeper understanding of the TFA intake with cardio-metabolic

risk factors.

Table 4.III.16: Multivariate linear regression analysis to determine the

association of TFA intake with dietary cholesterol, after adjusting for other

factors

Factors

Coefficient

Std.

Error

t

p

value

95% Confidence

Interval

Lower

level

Upper

level

TFA intake

> 2en% 9.64 3.49 3.58 0.005 5.802 19.368

Total Fat

intake 2.64 0.28 2.32 0.022 0.095 1.191

PUFA intake 0.14 0.49 4.37 0.000 1.172 3.108

Body weight 0.80 0.26 1.95 0.053 0.007 1.011

R2 = 0.32; In this model TFA intake < 1 en% was taken as the basis

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Table 4.III.17: Multivariate linear regression analysis to determine the

association of TFA intake with LDL-c, after adjusting for other factors

Factors

Coefficient

Std.

Error

t

p

value

95% Confidence

Interval

Lower

level

Upper

level

TFA intake

>2en% 11.80 5.93 4.69 0.009 4.523 17.199

Total Fat

intake 3.20 0.08 2.41 0.017 0.364 5.368

PUFA intake 1.83 0.39 4.72 0.000 1.066 2.601

n6 intake 0.09 0.05 1.78 0.077 -0.009 0.180

Body weight 2.00 0.91 1.68 0.032 0.301 3.105

R2 = 0.39; In this model TFA intake < 1 en% was taken as the basis

Thus, the present study indicated significantly higher levels of most of the cardio-

metabolic risk parameters viz weight, BMI, Fasting blood glucose, fasting serum

insulin, HOMA-IR, total cholesterol and LDL-c, among subjects with TFA intake

2 en% as compared to subjects with TFA intake less than 1 en% when adjusted for

their respective confounding factors. However, an increase in the total TFA intake

from less than 1 en% to between 1-2 en% did not show any significant increase in

these parameters.

Further, in the present study, high TFA intake (between 1-2 en% or >2en%) did

not indicate to have any significant effect on parameters like body fat %, waist hip

ratio, systolic/ diastolic blood pressure, serum triglycerides and HDL-c levels

The present study highlighted that apart from hydrogenated fats, TFA was also

present in some edible oils which otherwise are considered free from trans fatty

acids. Further, the results depict that commonly consumed fried and baked food

items have substantial amounts of TFA, with most of them containing TFA

content that was much higher than the tolerable limit of 2% of total fat enforced in

Denmark, the only country in the world that has a legal limit for trans fatty acids.

The study also demonstrated that although the oils under study as such do not

contain TFA, when subjected to heat, their TFA content increases on heating/ re-

293

heating or when they are used for frying/ re-frying depending on temperature. The

study also highlighted that in the case of edible fats (Desi ghee/ vanaspati), which

already contain TFA, when subjected to heat/ re-heat, their TFA content increased

further.

Further, the study highlighted that despite the study population being highly

educated, their knowledge regarding TFA were negligible and cooking and frying

practices were rather poor and their frequency of consumption of outside foods,

which are high in energy, total fat and TFA was quite high. The study also

demonstrated that in the population under study the consumption of fats, TFA in

particular was higher than the recommendation by ICMR/ NIN/ WHO guidelines

for prevention of non-transmittable chronic diseases, which are a leading cause of

death worldwide. Although it is a cross-sectional study, still it is able to show

some relation between TFA intake and cardio-metabolic risk factors, highlighting

the need for detailed intervention study.

4. IV LIMITATIONS AND STRENGTHS OF THE STUDY

Limitations And Strengths Of The Study

Due to financial and logistic constraints the study suffered certain limitations.

Field Work

The results of this study cannot be generalized for the population at large

as the subjects for this study were a group of female school teachers

representing the educated MIG/ UMIG group. Despite a large sample size,

our results apply to a relatively healthy set of women; our estimates may,

therefore be too conservative.

Since dietary intake was self-reported, it could be subject to reporting bias

though due precautions and check were observed during 2 day dietary

recall (1 working and 1 non-working day) and while administering food

frequency questionnaire.

Being a cross-sectional study, no concrete cause/ effect inferences can be

drawn from the dietary intake of the subjects.

The physical activity profile, which could also have thrown light on the

relationship between TFA intake and cardio-metabolic parameters, could

294

not be included in the present study due to time and resource constraints.

However, in the present study, this fact can be said to have lesser

relevance since all the subjects were female school teachers representing

the urban female population belonging to middle and upper middle income

group families, having a hectic and mechanised lifestyle.

Laboratory Analysis

Due to financial and time constraints, the laboratory analysis of fatty acid

profile including that of TFA for heated/ re-heated fats/ oils as well as that

of the food items itself could not be carried out for a still larger number of

samples.

The test food (pre-frozen French fries) could not be tested for the fatty acid

profile including TFA after frying.

Due to high variability in methods of food preparation, dietary habitsas

well as time/ resource constraints, fatty acid profile including TFA content

of a composite diet sample could not be done. However, due precautions

have been taken while entering the dietary data particularly giving due

emphasis to the type and amount of fats/ oils reported by the subjects.

The focus of the present study was to see the formation of TFA in fats/ oils

exposed to continuous heating/ re-heating at varying temperature, thus the

effect of heating and re-heating at the same temperature such as 180ºC has

not been assessed.

STRENGTHS OF THE STUDY

The present study is one of the few reporting the TFA content of fats/ oils

samples, its formation during heating/ re-heating and the dietary intake of

TFA in urban, north-Indian female population belonging to MIG/ UMIG

families.

This study will help in overcoming the lacunae relating to the TFA content

of commonly consumed fats/ oils/ foods items in India and will help in

generating a data base of laboratory analysed values of TFA of select

Indian fats/ oils/ food items.

Through the results of this study, it can now be established that trans fats

even if are absent in a particular oil initially, can still be formed during

295

heating/ frying. Thus, this study will open new dimensions for carrying out

future researches on ways to curb TFA formation during processing of

fats/ oils or their use in frying.

The present study can be used as a tool to help the government in driving

the food industry to come up with healthier options for the population at

large and persuading the government to put a strict check on the quality of

prepared foods available at eating outlets including road side vendors,

specifically pertaining to their TFA contents.

Further, the present study can be used to showcase the current scenario

regarding TFA consumption in India, and can later be used in studies

showing the secular trends.

The results of the present study will go a long way in helping educate the

masses regarding serious health effects of TFA consumption and also ways

and means to minimise formation of TFA at household and commercial

level by adopting healthier cooking practices for a better health.

Although it is a cross-sectional study, still it is able to show some relation

between TFA consumption and cardio-metabolic risk factors, highlighting

the need for detailed intervention study.

The study emphasizes, on the urgent need of limiting the levels of trans fatty acids

in the food supply. To achieve this, new technologies can be employed to reduce

the presence of trans fatty acids from edible fats/ oils. A variety of technologies

have already been implemented in the developed nations, while others are being

developed and refined to reduce or eliminate TFA in food products (Stender et al,

2006b). The most successful technologies are interesterification (which rearranges

the fatty acid within triglycerides to yield customized melting characteristics),

while the other one is altering the hydrogenation process to yield partially

hydrogenated fats lower in TFA (accomplished by using metal catalysts that

prevent the formation of trans isomers or promote the formation of cis isomers

and by changing the time and temperature of the hydrogenation process). Further,

numerous plant breeding and genetic engineering technologies are being used to

manipulate the fatty acid composition of oil seeds to increase oxidative stability

296

during deep-fat frying and to extend shelf life by decreasing the amount of

relatively unstable fatty acids (i.e. linolenic acid) or increasing the amount of

relatively stable fatty acids like oleic acid.

It is suggested that the future trend of having “zero trans fat” food products can be

achieved through several approaches, which include nutrition recommendations,

mandatory labelling and reformulation of food products to remove TFA. It should

be made mandatory for the manufacturers to comply with safe limits of TFA in

their products and accordingly incorporate the information on the label. With

respect to the direct approach relating to food products reformulation, the major

concern is with regard to the partially hydrogenated vegetable oils (PHVO),

because ruminant fats cannot be entirely removed from the diet, moreover, their

intake is rather low.

Due to the high TFA content, replacement of PHVO becomes rather mandatory;

and that these should be replaced byvegetable oils which are free from trans fatty

acid and have low saturated fatty acid and high cis-unsaturated fatty acid content.

Animal fats and tropical oils should be avoided to replace partially hydrogenated

vegetable oils due to their high saturated fatty acid levels. Products that have a

lower TFA and saturated fatty acid tend to cost more, and this may be a barrier to

their use by the budget conscious consumers, thus attempt should be made in the

direction of development of healthier fats/ oils and food products at economically

reasonable prices.

Further, with diabetes and heart disease emerging as the leading cause of death/

disability among Indian population, it is imperative that the consumers become

aware of the harmful effects of TFA, its sources and healthier options available for

maintaining their metabolic health. Therefore, educating Indian population

regarding effective ways of avoiding TFA in their diet is of immediate

importance.