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BETA GLUCAN , INSULIN

AND GLYCEMIC INDEX

BETA GLUCAN ,

GLYCEMIC INDEX &

INSULIN INDEX

By Nudrat Khan

T.Y.B.H.Sc,B-1

Roll no.: 106



O AT FIBER-

BETA GLUCAN



SOLUBLE DIETARY FIBER

Soluble dietary fiber -glucan

Insoluble dietary fiber

Adds bulk to your diet, making you feel full faster

Attracts water and turns to gel during digestion, trapping

carbohydrates and slowing absorption of glucose.

Lowers total and LDL cholesterol

Regulates blood sugar

Balances intestinal pH and stimulates intestinal fermentation

production of short-chain fatty acids

DIETARY FIBER

It is the indigestible portionof plant foods resistant to

digestion



The main component of oat soluble fiber is -glucan, a linear

polysaccharide composed of (1-3)(1-4)--linked glucosidyl subunits(fig)

It is also present in barley.

The percentage of -glucan in various whole oat product are:

As per FDA t he daily dietary intake levels of beta-glucan soluble is 3 g ormore from eit her whole oats or barley

BETA-GLUCAN

Oat bran 5.5 to 23 %

Rolled oats 4 %Whole oat flour 4 %



PHYSICAL PROPERTY

WATER SOLUBILITY

Solubility of -glucan depends on:Pretreatment or preparation

Extracting conditions

During frozen storage at -20 C, extractability of -glucan decreased more than

50 % in 8 weeks.

It increases with the concentration

It is sensitive to changes in molecular weight

It is dependent on:

Fiber·s solubility in water

pH of the gastrointestinal

Size of the fiber particle

Degree of processing food

VISCOSITY

WATER HOLDING CAPACITY



HEALTH BENEFIT

HYPOGLYCEMIC EFFECT:

Water soluble oat -glucan

exert their effect mainly by

increasing viscosity in small

intestine.

Food is incorporated

in the viscous -glucan

solution making it more

difficult for enzymes in

the intestine to degrade

the food components &

causing longer

digestion

Oat -glucans form

a protective layer along

the intestinal wall that

acts as a viscous barrier

or unstirred layer,

slowing absorption of

nutrients from the

intestine



O AT RECIPES

O AT DOSA

O AT UPMA

SAV OURYO AT

HALWA

O AT KA HALWA

O AT VADA CRUNCHY O AT POHA

O ATS CUTLET

O AT CHAAT



GLYCEMIC INDEX



The ability of the food items to rise the blood sugar is

measured in terms of glycemic index.

All foods are not digested or absorbed at the same rate

and hence their glycemic index levels are different.

Rate of ingestion

Food component

Method of cooking

Physiological effect

GLYCEMIC INDEX (GI)

Factors affecting glycemic response



It is a ranking system for carbohydrate content in

food portions based on their GI and the portion

size. The usefulness of GL is based on the idea

that a high glycemic index food consumed in

small quantities would give the same effect aslarger quantities of a low GI food on blood sugar.

GL = Carbohydrate content(g) x GI

100

GLYCEMIC LOAD(GL)



A lower glycemic response usually

equates to a lower insulin demand(but not always) and may improve

long-term blood glucose control and

blood lipids

A low GI food will release glucose

more slowly and steadily. A high GI

food causes a more rapid rise inblood glucose levels and is suitable

for energy recovery after endurance

exercise or for a person

experiencing hypoglycemia

GLYCEMIC INDEX (GI) [cont.]



FOOD ITEM GLYC0-60EMIC INDEX

Glucose 100

Carrots 90-95

Honey 87

Bread 70

Potato 70

Banana 69

Soya bean 43

Oatmeal 42

Apple 39

Ice-cream, milk 35-40

Rajma 29

Fructose 20-25

Glycemic index of common food



INSULIN

&INSULIN INDEX



Beta

cell

Glucose

Enters via

GLUT 2

K+ channels

close

Triggers

Calcium

influx

ATP is

released

Insulin is

released from

Secretoryvesicels



Insulin·s main glucoregulatory effects are mediated by a

transmembrane receptor found on insulin sensitive cells

Activation of insulin receptor tyrosine kinase leads to

autophosphorylation and hence to a cascade of intracellularevents

As a result Glucose transporter protein (GLUT 4) are

translocated within the cell to the surface membrane to increase

glucose influx into cell cytoplasm



The Insulin Index is a measure used to quantify thetypical insulin response to various foods.

The glucose and insulin scores of most foods are highly

correlated, but high-protein foods and bakery productsthat are rich in fat and refined carbohydrates "elicit

insulin responses that were disproportionately higher

than their glycemic responses.

Insulin indices may be useful for dietary management

and avoidance of non-insulin-dependent diabetes

mellitus and hyperlipidemia

INSULIN INDEX(II)



ORAL GLUCOSE

TO

LERANCE TEST(OGTT)



A glucose tolerance test in medical practice is the

administration of oral glucose to determine how quickly it

is cleared from the blood.

ORAL GLUCOSE TOLERANCE TEST(OGTT)

Preparation of the subject for OGTT

EXERCISE

Procedure.

�Fasting blood sample and urine samples

are collected.�The subject is given 75 g glucose load

orally dissolved in 300 ml water, to be

drunk in 5 mins.

�Blood & urine samples are collected at 30

mins interval for 2 hrs & then are

analysed.



RESEARCH ARTICLE



THE EFFECT OF -GLUCAN ON

GLYCEMIC AND INSULIN INDEX

H Mäkeläinen1, H Anttila1,2,5, J Sihvonen3, R-M Hietanen3,

R Tahvonen3, E Salminen1, M Mikola4,6 and T Sontag-Strohm2

1Functional Foods Forum, University of Turku, Helsinki, Finland2Department of Food Technology, University of Helsinki, Helsinki,

Finland3Department of Biochemistry and Food Chemistry, University of

Turku, Helsinki, Finland4Suomen Viljava/FinnCereal, R&D, Kielotie, Finland

European Journal of Clinical Nutrition(2007) 61, 779-785



To determine t he effect of oat products

wit h increasing -glucan content on

Glycemic index (GI)

Insulin index (II) of oat products

To establish t he effect of physical

properties of -glucan on t hese

physiological responses

1

2

OBJECTIVE



[A] SUBJECT:10 healt hy volunteers.

M=1 F=9

[B] PLACE: The university of Turku & Turku VocationalInstitute Campus

[C] INCLUSION CRITERIA:�Normal healt h status

�Normal glucose tolerance

�No-long term medication

�Mean Age -26.2 ± 4.3 years

�Mean BMI -21.1± 2.0

METHODOLOGY



[D] STUDY APROVED BY: The Medical Et hics Committee of

t he University of Turku and all volunteers gave written informed

consent.

[E] STUDY DESIGN:

2 mont hs duration(7 visits)

�OGTT: Glucose load= 50g glucose + 300 ml water

�Oat product: Four Oat bran product wit h different values of -glucan were

tested.

OGTT OGTT OGTTO AT

PRODUCT

O AT

PRODUCT

O AT

PRODUCT

O AT

PRODUCT



[F] ORAL GLUCOSE TOLERANCE TEST(OGTT)Prior to test :�

Subjects fasted overnight (8hrs),water consumption was limited to 2dL.

� Standardized meal was given for supper :

� Subjects were asked to avoid strenuous exercise & excessive alcoholconsumption 24 hrs before each test.

In t he morning of each test :� Baseline glucose level was checked.

� Test foods were eaten in 10 mins.

� Blood samples were collected after t he test drink every 15 minutestill 2 hrs.

Two piece of rye crisp

One slice of soft cheese

1dl of oatmeal

Small cookie

An apple or a pear



Oat bran(30g)

+

Oat

starch(3g)

+

41 g Glucose

+

4 dl water

2g -glucan 4g -glucan

4g -glucan

(FROZEN) 6g -glucan

Oat bran(45g)

+

Oat

starch(9g)

+

41 g Glucose

+

4 dl water

Oat bran(30g)

+

Oat

starch(3g)

+

41 g Glucose

+4 dl water

Oat bran(15g)

+

Oat

starch(6g)

+

41 g Glucose

+4 dl water

[G] TEST MEALS



TEST MEALS (CONT..)

Four oat bran product wit h different amount of -glucanwere tested.

Test drink was prepared by mixing oat bran (GI-Trim,

E03DGIJ1,29032004, Suomen Viljava Oy), oat starch

(01T2101,23052001, Suomen Viljava Oy),41 g glucose and 4dl water.

Oat starch was added enough to a serving to achieve t he 50g

of total available carbohydrates.

Product containing 4 g of -glucan was prepared twice and

one of t hem frozen for 13 days & t hawed before

consumption to study t he impact of freezing on viscosity.

Test and frozen meals were served wit h 1dl & 2dl water

respectively.



Test meals Oat bran

(g)

Available

carbohydrates

from oat bran

(g)

Oat

starch

(g)

Glucose

(g)

Total available

carbohydrates

(g)

Oat product with 2g of -

glucan

15 4.2 6 41 51.2

Oat product

with 4g of-

glucan

30 8.5 3 41 52.5

Oat product

with 6g of -

glucan

45 12.7 9 41 53.7

TABLE:1 Description of the oat test drink with different

amounts of -glucan



[H] EXTRACTION

Soluble fiber was extracted from test drink by enzymatic

digestion.

The apparent viscosity of t he soluble fiber extract was

measured at different concentration levels.

The concentration in t he soluble fiber extract was based in t he-glucan content in t he extract.

t he viscosity of t he sample extract were determined using a

rotational rheometer(RS 600, Haake)

The extraction & measurements were made at least induplication for each sample.



[I]THE -GLUCAN CONTENT

The -glucan content of dried samples, sample extract &suspensions were analyzed according to t he AACC met hod (32-

23 AACC 2000) using a -glucan assay kit (Megazyme

International Ireland Ltd, Bray Business Park, Brey, Ireland)

Solubility of t he -glucan was percentage of extracted -glucanof total -glucan in t he sample material.

[J]CARBOHYDRATE DETERMINATION

Carbohydrate content of test product were analyzed usingcommercial enzymatic hexokinase assay(Boehringer

Mannheim, R-Biopharm, Darmstadt, Germany)



[K]PLASMA GLUCOSE & INSULIN ANALYSIS�Glucose from plasma samples, stored at -70 C were analysed

using enzymatic hexokinase assay(Roche, Modulator BAnalysator)

�Insulin was analysed using immunological

electrochemiluminosens technique (ECLIA) ( Roche Modulator

A Analysator)

[L]CALCULATION OF GI & II�The incremental area under t he plasma glucose & insulin curve

(iAUC) were determined for each food according to

standardized criteria (FAO/WHO, 1998), ignoring any areabelow base line.

�Each subjects individual GI & II, for each food was calculated

�The indexes for each food was taked as t he average of all 10

indivaiduals



[M]STATISTICAL ANALYSES METHOD

Clinical test.statistical analyses were performed wit h

SAS/STAT software, version 9.1.3 of SAS system for

windows (© SAS Institute Inc, NC, USA)



RESULTS



FIGURE 1: Glycemic response curves to four oat products and glucose

load(mean value).



FIGURE 2: INSULIN RESPONSE CURVES TO FOUR OAT PRODUCTS AND

GLUCOSE LOAD(MEAN VALUE).



iAUC

Mean s.e.m

GLUCOSE

Oat product 2 g 83.7 6.1


Oat product 4 g (frozen) 64.3 8.4


INSULIN



Oat product 4 g (frozen) 41.8 8.3


TABLE 2:Glycemic(GI) and insulin indexes(II) of four oat

product(mean± s.e.m)



Product Extractability of

-glucan(%)

Amount of

extracted -glucan/serving

(g)

Oat product with 2 g of

-glucan

33±3 0.7


-glucan

30±2 1.2


-glucan(frozen)

28±3 1.1


-glucan

17±3 1.0

TABLE 3: The extractability of -glucan (mean ± s.e.m)



FIGURE 3: GLYCEMIC INDEX SHOWS AS A FUNCTION OF THE AMOUNT OF

EXTRACTABLE ETA -GLUCAN PER SERVING OF TEST DRINK .



DISCUSSION



Viscosity is the key functional property of oat -glucan. When digestion isdelayed , blood sugar increases more slowly, causing, causing low insulin

response.

-glucan solution in high concentrations was found to form cryogelsduring freezing - thawing step.

Cryogelation of aqueous amylase and amylopectin in our oat drink couldbe one of the explanation for slower glucose rise in frozen oat drink.

The similar viscosities of -glucan between our drinks referring nocryogelation of -glucan in our oat drink during freezing.

An average decrease of 3.8 GI unit per 1 g increase in -glucan wascalculated(Jenkins et al.,2002).

A 30-60% reduction in blood glucose peak can be achieved when -glucanconstitute 8-10 % of the carbohydrates in cereals.

DISCUSSION



DISCUSSION (CONT.) No linearity was found with the increasing dose of total amount of -

glucan and GI.

There is a high correlation between the GI values and the amount of

extractable -glucan.

Oats contain phytic acid, phenolic compounds and phytosterol, which are

antioxidant but may have an effect on the permeability of the intestine

The physical state of the oat starch may have been different in test drinks

as the oat product was extruded, but the starch added to test drinks was

not.

The amount of -glucan increases with the protein content.

A significant increase in oral in glucose stimulated insulin secretion was

observed after an oral fat load(Wuesten et al,2005).



The pulsatile manner of insulin secretion and short half life(3mins

or less) are other factors for fluctuation in insulin response.

Measurement of C-peptide can be used as an independent measureof insulin secretory rate.



CONCLUSION



This study showed that by increasing the amount of

extractable fiber, glycemic and insulinemic responses

were lower, the extractable -glucan was the most

important factor in GI dose-response study.

Oat bran high in -glucan can be incorporated into a

wide variety of innovative food products and have a

beneficial health effects.

Attention should be paid to the amount of extractable

-glucan , not to the total amount of -glucan

CONCLUSION



Cho Dreher. Handbook of Dietary fiber, pp. 497-

517

William J. Marshall and Bangert K. Stephen.

Clinical Biochemistry, pp. 257-264

Satyanarayana U. and U.Chakrapani.

Biochemistry, pp. 679-681

http://en.wikipedia.org/wiki/Oats

http://en.wikipedia.org/wiki/Glycemic_index

BIBLIOGRAPHY

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