food additives
TRANSCRIPT
FOOD ADDITIVES
Koushik DasSchool of Industrial Fisheries
CUSAT
Food additive Definitions Needs , Functions , Importance Types, Intentional/ Unintentional Legal amendments ,Acceptable daily intake
(ADI),FDA limits, Maximum use level Food additive safety Labeling, Guidelines packaging Common additives Thaw drip prevention Antioxidants ,Sequestrants , Color additives, Curing
agents, Emulsifier, Flavoring agents, Nutrient supplement , Sweetners, Preservatives
Antimicrobials Acidulants Safe food grade additives list ,Advice to public
OVERVIEW
‘ Any substance that becomes part of a food product either
directly or indirectly during some phase of processing, storage or packaging ’
What are Food Additives?
WHO (1965), ‘Food Protection Committee of the National Academy of Sciences (1959)
‘It is a substance or mixture of substances, other than the basic food stuff, which is present in food as a result of any aspect of production, processing, storage or packaging. This term does not include chance contamination.’
‘ Means any substance not normally consumed as food
by itself and not normally used as a typical ingredient of the food, whether or not it has nutritive value, intentional addition of which to food for a technological (including organoleptic) purpose in the manufacture, processing, preparation, treatment, packing, packaging, transport or holding of such food results or may be reasonably expected to result (directly or indirectly), in it or its byproducts becoming a component of or otherwise affecting the characteristics of such foods.’
The term does not include contaminants or substances added to food for maintaining or improving nutritional qualities.
CODEX
Unavoidable in the complex and integrated society in which we live as the
area of food production are separated from areas of consumption.
In present degree of urbanization, its impossible to maintain distribution
network without adding preservatives.
Great demand for convenience/ready to eat foods and heat and serve
products.
Essential to prevent rancidity of oils and for maintaining the shelf life of
high-moisture containing foods.
Food additives must not be used to disguise faulty processing and handling
techniques to cheat customers.
Need for additive
The food additives being used should present no risk to the health of the consumer at the levels of use.
Extending shelf life Improving colour, flavor, taste and other aesthetic attributes of food. Convenience Wide variety of appetizing, nutritious, fresh, and palatable foods. Small quantity with great impact. Maintain freshness and enhance keeping quality or stability of a food or to improve its
organoleptic properties Improve , preserve and provide nutritional quality of the food. e.g. The addition of iodine to salt. Make food more appealing Remain fresh in storage, transit and on the grocers’ shelves for an extended period of
time. Imparting or enhancing funtional characteristics like integrity, stability etc Assist in processing or preparing food.
FUNCTIONS
Foods are subjected to many environmental conditions,
such as temperature changes, oxidation and exposure to
microbes, which can change their original composition.
Food additives play a key role in maintaining the food
qualities and characteristics that consumers demand,
keeping food safe, wholesome and appealing from farm
to fork.
Importance of food additives
Flavorings : There are approximately 1100 to 1400 natural and
synthetic flavorings available to food processors.
Stabilizers : These are used to keep products in a set state
Colorants : Ninety percent are artificial and do not contain any nutritional value.
Sweeteners : These are designed to make the foods more palatable.
Preservatives: Helps maintain freshness and prevents spoilage that is caused by fungi, yeast, molds and bacteria.
Acids/Bases : Provides a tart flavor for many fruits and is used in pickling as well as putting the carbonation in soft drinks .
Antioxidants: Prevent oxidative rancidity of foods high in fats and oil.
Types of Food Additives
Types of additivesAdditives may be:• Natural – found naturally, such as extracts from beetroot juice (E162), used as a colouring agent;
• Manmade versions – synthetic identical copies of substances found naturally, such as benzoic acid (E210), used as a preservative;
• Artificial – produced synthetically and not found naturally, such as nisin (E234), used as a preservative in some dairy products and in semolina and tapioca puddings.
Intentional additives are those ingredients that are added intentionally to
the seafood and are identified on the ingredient label of the food.
Unintentional additives are those that typically occur in foods in trace
quantities as a result of production, processing, storage, or packaging
practices.
E.g.. Environmental contamination (surface water runoff, or industrial
spills).Residues of pesticides, herbicides and fungicides on fruits and
vegetables, of detergents used in washing foods, and of detergents and
sanitizers used on utensils and equipment are likely to carry over into
foods.
Intentional v/s Unintentional Additives
Various amendments by the government created 3 legal
categories of additives:i. Those requiring governmental approval in order to be used (“food
additives” and “color additives”)
ii. Those approved by the Government prior to 1958 (“prior-sanctioned”
substances)
iii. Those not requiring government approval (Generally Recognized As
Safe- GRAS-substances)
‘Its an estimate by Joint FAO/WHO Expert Committee on Food Additives (JECFA) of the amount of a food additive, expressed on a body weight basis that can be ingested daily over a lifetime without appreciable health risk.’
Acceptable Daily Intake (ADI)
FDA first determines the lowest limit at which a
substance will produce its desired effect and also the
maximum level at which it does not produce harmful
effects, and then it requires the use level of the additive
to be no more than 1/100th of the “no effect” level of
safety.
Thus there is a minimum 100-fold margin of safety
imposed on the additive.
How is a limit fixed by FDA?
Maximum use level‘ It is the highest concentration of the additive
determined to be functionally effective in a food or food
category and agreed to be safe by the Codex Alimentarius
Commission’
Its generally expressed as mg additive/Kg of food
Sodium propionate
Calcium propionate Sorbic acid
Potassium metabisulphite Sod. Metabisulphite
Sorbitol Benzoic acid
Sod. Benzoate Fumaric acid
Sodium carboxy methyl cellulose
Sodium alginate
Agar agar Alginic acid
Calcium alginate Gelatin
Ascorbic acid BHA
BHT Caramel
Anattor colour
Safe of food additives(food grade)
a) Only the additives which present no appreciable health risk to
consumers at the use level proposed by the JECFA shall be
endorsed and included in the standard.
b) ADI, its probable daily intake from all food sources for special
group consumers (diabetic, medical diet, sick individual on
formulated liquid diet) will be taken into account
c) The quantity of an additive should be at or below the maximum
use level and is at lowest level necessary to achieve the intended
technical effect.
d) It should be of food grade quality and is prepared and handled in
same way as a food ingredient.
e) Carry over of a food additive from a raw material to other
ingredient is unacceptable for foods such as infant formula,
follow-up formulae and formulae for special medical purposes,
complementary foods for infants and young children
Food Additive Safety
Federal government regulations generally require that all food
ingredients, including direct additives, be listed on the package
label by their common names in order of weight.
Labeling
• The EU (European Union) countries have drawn a list of 314 safe
food additives. Each of them is given an E number.
17
Guideline1-budget calculation on the food additive use levels
should be performed on the ready-to-eat product.
Guidelines2-an additive when allocated an ADI “not specified”, be
allowed for use in foods in general with no limitation other than in
accordance with GMP. It does not mean that unlimited intake is
acceptable.
Guidelines3-in cases where ADI of additive has been unable to
allocate should only be authorized in accordance with conditions
specified.
Guidelines4-if additive is used both in solid food and beverages,
fraction of the ADI may be allocated .(e.g.. FS=1/4 and FB=3/4)
FS- fraction for use in solid foods
FB- fraction for use in beverages
Guidelines for the development of maximum levels for the use of food additives with numerical
acceptable daily intakes.
Plastic consists of its polymer, plasticizers, antistatic agents,
stabilizers and antioxidants, etc.
Some components are more likely to migrate into foods than
others, esp. residual plastic monomers and plasticizers.
The plastic monomers of most health concern are vinyl chloride,
and styrene.
Migration of Packaging
Situation that can promote contaminants migration:
• Heating containers (by microwave oven) which are designed
solely for chilled foods.
• Overheating ‘heat resistant’ containers.
• Coming close to laminating leftovers covered with cling wrap in
the microwave.
Artificial Colorings-natural plant extracts, dyes and artificially created.
Artificial Sweetners-add flavor but not calories because they are 100s of times
sweeter than sugar or high fructose corn syrup so very little is used.
BHA and BHT-protect fat from going rancid.
Calcium Propionate-protect bread and baked goods from mold and bacterial growth.
Carrageenan-is a thickener made from seaweed.
Citric acid-tangy sour flavour, used as preservative.
MSG-flavour of protein rich food is enhanced
Nitrogen-used in packaging keeping foods fresh and safe through a process called
nitrogen flushing.
Nutritional ingredients-improve nutritional profile of the foods and can get enough
calcium, fiber and other nutrients.
Sodium benzoate-used in acidic foods. Prevents bacteria, mold and yeast. If
combined with ascorbic acids, it can form benzenes under certain conditions.
Sulfites-prevent bacterial growth, improve quality of bread dough.
Some additives that are found in processed foods
Loss of large amount of moisture from frozen seafood
during thawing or cooking. Thaw drip causes
Weight loss Nutritional loss Loss of appearance Texture and flavor loss
Thaw drip prevention
It was found that a molar ratio of alkali metal oxide to
P2O5 of about 1 to 2:1 was sufficient to reduce drip
without any undesirable side effects.
Soaking in a solution of molecularly dehydrated
phosphates of sodium and potassium (sodium
tripolyphosphate commonly used)
Prevent oxidative rancidity in foods high on fats and oils.
When the preservative do not interfere with the antioxidant and
work in unison with it in prolonging shelf life, the effect is said to
be synergetic.(e.g.. Sorbic acid and its salts)
Application:
As dip or spray
As a glaze on frozen fish (BHA or BHT are incorporated into the
wax used in the glassine liner in packages
Antioxidant types
Water soluble (synergistic) type
Fat soluble type
ANTIOXIDANTS
•Naturally occuring substances that act as antioxidants are
tocopherols, but they are rarely used as additives because they are
more expensive than synthetic antioxidant.
•They are effective in low concentrations (0.01-0.02%)
•Mixed antioxidants sometimes act synergistically.
•Amount of antioxidant used
• Water soluble:trace-0.2% by weight of processed tissue
• Fat soluble: 0.005-0.05%
•Ascorbic acid (E300) is one of the most widely used antioxidants
and shows both pro and anti oxidant activity depending on the
concentration ETC
Butylated hydroxytoluene (BHT) and Butylated hydroxyanisole
(BHA) are radical scavenger, have low acute toxicity.(GRAS)
They interfere propagation step during lipid peroxidation.
Curiously, these antioxidants can exhibit both anti tumorogenic
and tumorogenic effects, and they are known to alter enzyme
activity affecting detoxification of xenobiotics.
However, BHA and BHT are still permitted to be used in food
0.02% (200 ppm) of the fat oil content of the food product or 50
ppm (combined BHA and BHT) if they are used in dry low-fat
product.
Phenolic Antioxidants
Establish, maintain & enhance the integrity and functional properties of food
products.
Stabilise color, flavor and texture
Synergist action with antioxidants.
It reacts with metal in the food to form complexes, which tend to alter the
properties and effects of the metal in the food.
These are not antioxidants but serve as scavengers of metals which catalyze
oxidation. Sequestrants stabilize color, flavor, and texture in foods.
When metallic ions are released due to hydrolytic or other degradative reactions,
they are free to participate in reactions leading to discolouration,oxidative rancidity,
turbidity and flavor changes in foods.
E.g.: Citric acid and its derivatives, phosphates and salts of ethylene diamine tetra
acetic acid (EDTA).
Solution of EDTA (0.8 to 1.5% solution) and alum have been very successful in
preventing blue-green or gray discolorations in canned foods.
Struvite formation can be prevented by addition of chelating agents.
SEQUESTRANTS/CHELATING AGENTS
• Restore colour lost during processing or storage.
• Ensure that each batch produced is identical in
appearance or does not appear ‘off’.
• Reinforces colour already in foods, e.g. enhance the
yellowness of a custard.
• Give colour to foods which otherwise would be colourless
(e.g. soft drinks) and so make them more attractive
appetizing and more saleable.
• To ensure colour consistency.
Why use Colour additives?
Would you like this soft drink if no artificial flavouring and colouring had been added to it?
Common example:
PROBLEM REMEDY
Greening of tuna meat while processing
Injection of 0.3% cysteine or homocysteine, if proper distribution of flesh is ensured, can prevent negate greening in tuna.Cysteine can also be added to a slurry of flesh together with an antioxidant.
Increasing content of white meat in tuna flesh (also bonito)
Injecting a molecularly dehydrated phosphate solution into whole tuna . Orthophosphate added with or without its salt. The yield of white meat increases by 15% and flavour and odour is more delicate and the cooked meat becomes more tender and moist
Discolouration of salmon roe from reddish(fresh) to dark brown
Treatment with nitrites (potassium);nitrites are suspected to be carcinogenicCitrate with a sulfite/bisulfite/meta bisulfite
COLOUR ADDITIVES
PROBLEMS REMEDY
Loss of natural pink colour of shrimp due to oxidative reaction and action of surface flora
1.Acid treatment using inorganic acid improves colour and appearance and kills surface bacteria thus reducing spoilage.Ascorbic acid mixed with HCl gives better results(1:10 ratio by weight) with total acids 0.2 to 0.5% by wt and the pH between 1 and 3. Raw, peeled shrimp dipped in solution for 15-30s at 2-4°C. This is followed by washing and pH adjustment using a suitable weak alkali.2.Treatment with a solution of canthaxanthin (pink) or apocarotenol (brown) (compounds similar to asthaxanthin which is the natural pink pigment in shrimp) at 13-18°C. Carotenoid should be 5-20% by wt3.Soaking in a solution of synthetic colors like paprika along with cryoprotectants for upto 4hrs at about 2-5°C is a common practice in shrimp processing plants.
Give desirable colour, flavor, discourage growth of microorganisms
and prevent toxin formation.
Nitrite also inhibits the growth of clostridium and streptococcus. It
lowers temperature to kill C.botulinum.
Nitrites and Nitrates-the level of nitrate must not exceed 500ppm
and nitrite must not exceed 200ppm in smoked or cured tuna fish.
Sodium nitrite has been found to be good preservative for fish
when incorporated into the ice at a level of 0.1-0.5%.
Nitrites decompose to nitric acid, which forms nitrosomyoglobin
when it react with heme pigment in meat and forms a stable red
colour.
Cooking nitrite cured meat products results in formation of small
amounts of N-nitrosamines, that are potent carcinogens. Nitrite in smoked fish should be monitored as well, needs 100 ppm in vacuum
packed smoked fish, to prevent botulism.
Curing agents
Sulfites (SO3) are used as antioxidants
prevent enzymatic browning,
inhibit bacterial growth
acts as bleaching agent & dough conditioner
prevent melanosis in shrimp
They are present in the form of sulfur dioxide, sodium sulfite, sodium
metabisulfite, sodium bisulfite. Individuals with asthma problem are sensitive to sulfites.
Sulfites
Sulfites sprayed onto foods produce the most rapid allergic reactions. Sulfites can destroy thiamin- banned by FDA to be used in important
sources of the vitamin.
Sulfites are not permitted to be used in meats.
Their limit in shrimp is 100 ppm. The ADI for sulphites (expressed as
sulphur dioxide) is 0.7 mg/kg body weight.
Cases of sulfite poisoning in US (1997)
canned tuna contained sulfites (not declared on the
label), sulfites were identified from one of the
ingredients – the hydrolyzed vegetable protein (used as
flavor enhancer).
Emulsifiers, stabilisers, gelling agents
and thickenersEmulsifiers help mix ingredients together that would normally
separate, e.g. Lecithins (E322).
Stabilisers prevent ingredients from separating again, e.g.
locust bean gum (E410).
Emulsifers and stabilisers give food a consistent texture, e.g.
they can be found in low-fat spreads.
Gelling agents are used to change the consistency of a food,
e.g. pectin (E440).
Thickeners help give food body, e.g. can be found in most
sauces.
WHY USE FOOD FLAVOURINGS? To enhance flavor of food
To restore the original flavor which may be lost during food processing
To add flavor to foods which are tasteless themselves (e.g. ice cream, jelly)
Common flavourings.
Flavour enhancers bring out the flavour in foods without imparting
a flavour of their own, e.g. monosodium glutamate (E612) is added
to processed foods. For example some soups, sauces and
sausages.
Natural flavor substances such as Spices and their extracts, herbs,
roots, essence and essential oils have been used.
Flavors of the substance are not uniform as they vary with season
and area of production.
Natural are now replaced by synthetic flavour materials. It includes
esters, aldehydes,ketones, alcohols and ethers, smoke flavors of
glutamates
Usually used in small amounts to give a particular taste. These do
not have E numbers because they are controlled by different food
laws. Ingredients lists will say if flavourings have been used, but
individual flavourings might not be named.
Flavoring agent
Monosodium glutamate is a
white solid. It possesses little
flavor of its own, but it can
‘bring out’ the flavor of foods.
It is therefore a flavor
enhancer.
An important food additive for prevention of bacterial growth, for
necessary technical reason, or for flavor.
By weight, salt is composed of 40% sodium and 60% chloride. One
teaspoon of salt weighs 5 grams and contains about 2,300 mg of
sodium.
Both sodium and chloride ions are important in physiological
processes, but excess sodium directly cause hypertension (high
blood pressure), a major risk factor for heart disease, stroke and
kidney disease.
FDA limit sodium to 2400 mg daily for a 2000- calorie diet.
The best way to reduce salt intake: read labels and make educated choices!
Salts
Sodium labelling defined by FDA: Sodium free or salt free: Less than 5 mg per serving Very low sodium: 35 mg or less of sodium per serving Low sodium: 140 mg or less of sodium per serving Low sodium meal: 140 mg or less of sodium per 3 ½
oz Reduced or less sodium: At least 25% less sodium
than the regular version Light in sodium: 50% less sodium than the regular
version Unsalted or no salt added: No salt added to the
product during processing
When foods are processed, some loss of nutrients take place. So
some additives are used as nutrient supplements to restore the
original value
Iodine in the form of potassium iodide is added to common salt to
safeguard against goiter.
Nutrient supplement
Sweeteners• Intense sweeteners, e.g. saccharin, have a sweetness many times that of sugar and therefore are used in small amounts, e.g. in diet foods, soft drinks, sweetening tablets;
• bulk sweeteners, e.g. sorbitol, have a similar sweetness to sugar and are used at similar levels.
Nonnutritive sweeteners• Low calorie sweeteners, such as saccharin, aspartame etc.
Saccharin
• It is 300 times sweeter than sugar. ADI for saccharin is 2.5 mg/kg body weight.
• It is not metabolized (no calories).
• It comes in the forms of pure saccharin, ammonium saccharin, calcium
saccharin, and sodium saccharin.
• Saccharin-containing products are still required to have warning statement on their labels on
doubts being carcinogenic.
Common methods to preserve food include:
Canning Cook food and then seal it in tin cans under
sterile conditions.
Drying Dry food in the sun or in special ovens. Drying takes
away the water needed by microbes.
Freezing and refrigeration Freeze food quickly. Freezing
turns liquid water into ice, thus controlling the growth of
microbes. Refrigeration slows down biochemical changes of
microbes.
Irradiation Expose food to gamma rays from certain
radioactive isotopes for a short time. The microbes are
killed at once.
Using preservatives
Preservatives• Prevent the growth of micro-organisms which could cause food
spoilage and lead to food poisoning;
• Extend the shelf-life of products, so that they can be distributed
and sold to the consumer with a longer shelf-life.
• Salting and sugaring are two of the oldest methods of preserving food.
ANTIMICROBIAL ADDITIVES• Reduce the spoilage effect of microorganisms
• Prolong shelf life & improve keeping quality
• They are used to
• To supplement the effect of processing methods like
freezing, thermal processing, drying, smoking etc
Properties of a good
preservative• Should be active at low concentration
• Should not be toxic or otherwise harmful to humans
• Should not alter the flavor, taste or other characters of food
• Should have prolonged effect
• Should resist process conditions
• Should be easily available and economical.
Preservative additives employed at levels below lethal concentration for
microbes-only inhibitory.
Oils of oregano and cinnamon have strongest antimicrobial activity,
followed by lemongrass, thyme, clove, bay, marjoram, sage and basil oils.
Oregano oil (0.05%, v/w) reduced growth of P. phosphoreum in naturally
contaminated MAP cod fillets and extended shelf-life from 11-12 d to 21-
26 d at 2 degrees C.
Chitosan inhibits or retards growth of gram-positive and gram negative
bacteria isolated from fishery products. Therefore Chitosan could be used
to increase the shelf life of fishery products.
Develop an antimicrobial packaging-Need to release active agent slowly
from the packaging on the food surface
Antimicrobial additive
Ammonia- 0.1-1% by weight
Chlorine-1000µg/ml free chlorine solution
Buffered mixture propionic and benzoic acid may be incorporated
into ice used to preserve fish at the rate of 0.5 to 10g of mixture
per L of ice.
Wood smoke-Add desired flavors, preserving, improvement in the
colour of the inside of the meat and in the finish, or “gloss”, of the
outside and a tenderizing action on meats.
Spices and other condiments- Prevent growth of organism in foods
Thyme, bay leaves, marjoram, savory, rosemary, black peppers
and others have only weak inhibitory powers and may even
stimulate some yeast and moulds.
Sorbic acid and salt-should not be more than 1%
Acetic acid and acetates- acid must be present in a concentration
above 0.5%
Formic acid-marinades(0.3g/kg)
Color and flavor enhancement, preservative
For gelling, leavening or inversion
As stabilizers for antibiotics
e.g.: malic acid, fumaric acid, adipic acid, succinic acid, succinic
anhydride, citric acid, propionic acid, sorbic acid, acetic acid, lactic
acid, tartaric acid
Citric acid-in canning of crab meat(1%solution) to inhibit color
change, development of off flavor and off odors
Acidulants
Antibiotics•Very effective
•Not permitted as their can be development of resistant organisms
•Eg.
• OTC (Oxytetracycline)
• CTC (Chlorotetracycline)- 10-100mg/L dip treatment
• Subtilin
• Tylosin
Evaluate through comprehensive treating and scientific
procedures.
Chemical analyses measure the direct additives
accurately in minute quantities.
Variety of animal tests used to estimate the safety of a
additive in human diet.
Also required studies on metabolism, genetic toxicity,
carcinogenicity and reproduction.
Testing methods
Buy foods from reputable sources.
Read the label of prepackaged food carefully in particular the
ingredient list for food additives added (if any) which you could
accept.
People with allergic condition, such as asthma patients, may
experience hypersensitive reaction due to some food additives like
sulphur dioxide and should be careful in selecting food. Advice
from medical professionals may be sought when necessary in
Hazards of preservatives.
Advice to the public of food additives
THANK YOU….