2. Food Additives

8/13/2019 2. Food Additives

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Food Additives

Despite their association with modern-day food production, food additives havebeen used for centuries in preserving

and improving the appearance andcolour of food.


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Content

Preservatives

Flavouring Agents

Colouring Agents

Emulsifiers, Stabilizersand Thickeners

Nutrients

Antioxidants

Harmful Effects of FoodAdditives

Monitoring of Use of

Food Additives


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Preservatives

Flavouring Agents

Colouring Agents


Nutrients

Antioxidants



Food Additives

Preservatives

Nitrates (III) andNitrates (V)

Sulphur Dioxide and

Sulphates (IV) Benzoic Acid and

Benzoates

Sorbic Acid and

Sorbates Propanoic Acid and

Propanoates


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Flavouring Agents

Spices

Monosodium

Glutamate

Esters

Saccharin

Artificial Flavouring

Common food

Flavouring

Preservatives

Flavouring Agents

Colouring Agents


Nutrients

Antioxidants



Food Additives


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Colouring Agents

Natural Colourings

Synthetic Colourings

Preservatives

Flavouring Agents

Colouring Agents


Nutrients

Antioxidants



Food Additives


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Emulsifiers, Stabilizers and

Thickeners

Carboxymethymethyl

cellulose

Xanthan Gum Pectin

Dextrins

Sodium Alginate

Preservatives

Flavouring Agents

Colouring Agents


Nutrients

Antioxidants



Food Additives


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Nutrients

Vitamins

Minerals & Iodine

Preservatives

Flavouring Agents

Colouring Agents


Nutrients

Antioxidants



Food Additives


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Antioxidants

Ascorbic Acid and

Ascorbates

BHA and BHT

Preservatives

Flavouring Agents

Colouring Agents


Nutrients

Antioxidants



Food Additives


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Harmful Effects of Food Additives

Allergies

Hyperactivity

Long-term illnesses

Controversy over BHA

and BHT Side Effects of MSG

Toxicity and Potentcarcinogenic Nature ofNitrates (III)

Toxicity of sulphurdioxide

Potent carcinogenicnature of saccharin

Preservatives

Flavouring Agents

Colouring Agents


Nutrients

Antioxidants



Food Additives


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Monitoring the Use of Food

Additives

By Research

By Legislation

Preservatives

Flavouring Agents

Colouring Agents


Nutrients

Antioxidants



Food Additives


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Nitrates (III) and Nitrates (V)

Nitrates(III)andnitrates(V)ofsodiumand

potassium

Slowdownmicrobialgrowth

MaintainthepinkcolourofmeatPreventbotulismincannedfoods


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Sulphur Dioxide and Sulphates (IV)

Maintain the colour

and the vitamin C

content of the food

Prevent fruit tissuesfrom browning

Provide an acidic

medium that is not

favourable for

microbial growth


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Benzoic Acid and Benzoates

Preventing mould and yeast from growing

Widely used in jams, fruit juices, oyster

sauce(), margarine(), non-alcoholic

beverages and pickled() products


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Sorbic Acid and Sorbates

Prevent mould

formation

Mainly used in

cheese and in flourconfectionery()


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PropanoicAcidandPropanoates

Prevent the

formation of mould in

bread.

Used in chocolateproducts and cheese.


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Spices

Cinnamonand gingerare

examples of natural spices

Chemicals which stimulate our

taste buds Commonly used in chicken

broth, oyster sauce, soup bases

for instant noodles, many fast

foods and restaurants dishes.


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Monosodium Glutamate (MSG)

Does not add any taste to food

But is a flavour enhancer. Itcan bring out the flavour offood, particularly meat

productsCommonly used in chickenbroth, oyster sauce, soupbases for instant noodles anddim sums().

Side Effects of MSG


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Esters

The sweet smell in fruit is due to the

presence of ester compounds

Naturals fruit flavours can be extracted

from fruits and other plant materials

Most fruit flavouring used in the food

industry are synthetic compounds

Esters are used in ice-cream and

many fruit juices

e.g. ethyl ethanoate which has a

pineapple flavour.


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Saccharin

Kind of sweetener

Used as a sugar substitute or diet sugar.

Saccharin has no food value

Sweetness about 500times that table sugar


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Artificial Flavouring

Although flavourings can be extracted

from natural sources, the demand for

flavouring in the food industry has

outstripped the supply. Therefore,artificial flavours are being produced.

Artificial flavouring are closely resembles

the natural product.


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Common food Flavouring

Flavour Food AdditiveCamphor Bornyl acetate

Cinnamon Cinnamaldehyde

Ginger Ginger oil

Grape Methyl anthranilate

Lemon Citral

Orange Orange oil

Pear Amyl butyrate

Peppermint Menthol

Rum Ethyl formate

Spearmint Carvone

Spicy Ethyl cinnamate

Vanilla Ethyl vanillin

Wintergreen Methyl salicylate


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Natural Colourings

CaramelBrown colouringUsed in oyster sauce

CaroteneYellow dye present in carrotsUsed to colour butter and margarine

ChlorophyllGreen dye extracted from plantsUsed to colour edible oils


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SyntheticColourings

Indigo carminePurple blue dye combinationwith yellow colouringUsed for confectionery, candiesand liqueurs

TartrazineYellow dyeUsed in Pudding Powders,candies, ice-cream and pop drinks

Sunset Yellow

Orange dyeUsed in candies, honey-likeproducts, sea salmons andcrabs()


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Carboxymethylcellulose

Used to stabilize

batter for coating

steaks and fish fillets


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Xanthan Gum

Used in Salad dressings, dessert

toppings and frozen pizzas


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Pectin

Used to make the gel in jams and jellies


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Dextrins

Used to emulsify and stabilize cream,

mayonnaise() and salad dressings


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Sodium Alginate

Commonly used to emulsify and stabilize

ice-cream, yogurt, sauces and syrups(

)


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Vitamins

Vitamin C

for fruit juices

Vitamin B

for enriched flourVitamin D

for milk and margarine


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Minerals & Iodine

Ammonium ferric citrate in infant milk

formulations and bread flour

Iodine in iodized salt


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Ascorbic Acid and Ascorbates

Ascorbic Acid

Chemical name of Vitamin C

Reducing in nature

Reduce the amount of dissolved oxygen in

food

Ascorbic Acid and Ascorbates

Antioxidants for water-soluble fatty products


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BHA and BHT

BHA(butylatedhydroxyanisole)

BHT(butylatedhydroxytoluene)

Commonlyusedantioxidantsforfat-solublefattyproducts

Similarpropertiesto thenaturalantioxidant,vitaminE


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BHA and BHT

They appear to work by donating the H atom of theOH group to the free

hydroperoxide redical (ROO) involved in the autoxidation of fats and oil, thereby

stopping the chain reactions in oxidative spoilage.

AH + ROO ROOH + A

where AH represents the antioxidant, and A is a radical derived from the

antioxidante.g.

O

C(CH3)3

OCH3

O

C(CH3)3

OCH3Antioxidant radicals from BHA


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Allergies

Some people are allergic to certain

additives. It is suspected that MSG and

Tartrazine may cause rashes, stomach

upsets and asthma.


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Hyperactivity

In the 1970s, it was suggested by some

scientists that food additives may be linked to

hyperactivity and attention deficient disease

(ADD) in childrenSome hyperactive children show improvement

when fed with additive-free diets

Well-controlled studies have produced no

evidence of these additives causing

hyperactivity or learning disabilities in children


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Long-term illnesses

Some additives, such as sodium nitrate

(III), are suspected to be carcinogens

Some additives are believed to be the

causes of some long-term illnesses


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Controversy over BHA and BHT

Small amount of BHT shown to prevent

cancer

Larger amounts can cause cancer


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Side effects of MSG

Some people allergic to

MSG

Dizziness

ThirstHeadache

Chest pain

SweatingAbdominal discomfort

Chinese Restaurant

Syndrome /

MSG Syndrome

T i it d t t i i


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Toxicity and potent carcinogenic

nature of nitrates

Short term

Decrease in haemoglobin in blood

Long term

Malnutrition

Growth retardation

Impairment of reproductive capacity

reduced lifespan

To icit and potent carcinogenic


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Toxicity and potent carcinogenic

nature of nitrates (III)

In the stomach, nitrates (III) are first converted to nitric

(III) acid.

NaNO2(aq)+ HCl(aq)HNO2(aq)+ NaCl(aq)

Under certain conditions, nitric (III) acid reacts withsecondary amines, which are released during

digestion of proteins, to from nitrosamines.

HNO2(aq)+ R2NH(aq)R2N-N=O(aq)+ H2O(l)

Stomach acid

Secondary

aminenitrosamine


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Toxicity of Sulphur Dioxide

Sulphur dioxide is poisonous

Attack respiratory system

Potent carcinogenic nature of


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Potentcarcinogenicnatureof

saccharin

Bitter aftertaste which renders it

unpleasant to some users

High doses cause cancer


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Research

Salt, sugar, vitamins and some minerals

had long been used as additives to food

and are Generally Recognized As Safe

(GRAS)

No food additive may be used unless it

has been extensively tested on animals


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Legislation in World

In USA

Food and Drug Administration (FDA) is

responsible for monitoring the safety, purity,

and wholesomeness of food additivesIn UK

Food Advisory Committee compiles in

European Economic Community, a permitted

food additive is assigned a E number.


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Legislation in World

Type of Additive E Number

Colouring Most begin with 1

Preservatives Most begin with 2

Flavourings Not numbered

Antioxidants E300321

Emulsifiers and stabilizers E322 and some numbersbetween E400 and E495

Sweeteners Most begin with 4 or 6


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Legislation in Hong Kong

Legislate permissible additives and maximumlimits of additives in particular foods

Require supply of information as tocomposition of substances used in thepreparation of food

Check on food labelingInspect food- processing industries

Take samples for chemical analyses on foodsand food additives

Seize and destroy foodProsecute for false labeling, advertisement,using non-permitted additives or usingadditives beyond the permissible limits.

Documents

2. Food Additives