Food Additives

1. Food Additives Despite their association with modern-day food production, food additives have been used for centuries in preserving and improving the appearance and colour of food.

2. Syllabuses 2002

3. Syllabuses 2002

4. Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Content

5. Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Nitrates (III) and Nitrates (V) Sulphur Dioxide and Sulphates (IV) Benzoic Acid and Benzoates Sorbic Acid and Sorbates Propanoic Acid and Propanoates Preservatives

6. Spices Monosodium Glutamate Esters Saccharin Artificial Flavouring Common food Flavouring Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Flavouring Agents

7. Natural Colourings Synthetic Colourings Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Colouring Agents

8. Carboxymethymethylcellulose Xanthan Gum Pectin Dextrins Sodium Alginate Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Emulsifiers, Stabilizers and Thickeners

9. Vitamins Minerals & Iodine Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Nutrients

10. Ascorbic Acid and Ascorbates BHA and BHT Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Antioxidants

11. Allergies Hyperactivity Long-term illnesses Controversy over BHA and BHT Side Effects of MSG Toxicity and Potent carcinogenic Nature of Nitrates (III) Toxicity of sulphur dioxide Potent carcinogenic nature of saccharin Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Harmful Effects of Food Additives

12. By Research By Legislation Preservatives Flavouring Agents Colouring Agents Emulsifiers, Stabilizers and Thickeners Nutrients Antioxidants Harmful Effects of Food Additives Monitoring of Use of Food Additives Monitoring the Use of Food Additives

13. Nitrates (III) and Nitrates (V) • Nitrates(III)andnitrates(V)ofsodiumandpotassium • Slowdownmicrobialgrowth • Maintainthepinkcolourofmeat • Preventbotulismincannedfoods

14. Sulphur Dioxide and Sulphates (IV) • Maintain the colour and the vitamin C content of the food • Prevent fruit tissues from browning • Provide an acidic medium that is not favourable for microbial growth

15. Benzoic Acid and Benzoates • Preventing mould and yeast from growing • Widely used in jams, fruit juices, oyster sauce(蠔油), margarine(黃油), non-alcoholic beverages and pickled(醃菜) products

16. Sorbic Acid and Sorbates • Prevent mould formation • Mainly used in cheese and in flour confectionery(糖果)

17. PropanoicAcidandPropanoates • Prevent the formation of mould in bread. • Used in chocolate products and cheese.

18. Spices • Cinnamon and 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.

19. Monosodium Glutamate (MSG) • Does not add any taste to food • But is a flavour enhancer. It can bring out the flavour of food, particularly meat products • Commonly used in chicken broth, oyster sauce, soup bases for instant noodles and dim sums(點心). • Side Effects of MSG

20. 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 juicese.g. ethyl ethanoate which has a pineapple flavour.

21. Saccharin • Kind of sweetener • Used as a sugar substitute or diet sugar. • Saccharin has no food value • Sweetness about 500 times that table sugar

22. 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.

23. Common food Flavouring

24. Natural Colourings • Caramel→Brown colouring→Used in oyster sauce • Carotene→Yellow dye present in carrots→Used to colour butter and margarine • Chlorophyll→Green dye extracted from plants→Used to colour edible oils

25. SyntheticColourings • Indigo carmine→Purple blue dye combination with yellow colouring→Used for confectionery, candies and liqueurs • Tartrazine →Yellow dye →Used in Pudding Powders, candies, ice-cream and pop drinks • Sunset Yellow→Orange dye→Used in candies, honey-like products, sea salmons and crabs(蟹)

26. Carboxymethylcellulose • Used to stabilize batter for coating steaks and fish fillets

27. Xanthan Gum • Used in Salad dressings, dessert toppings and frozen pizzas

28. Pectin • Used to make the gel in jams and jellies

29. Dextrins • Used to emulsify and stabilize cream, mayonnaise(蛋黃醬) and salad dressings

30. Sodium Alginate • Commonly used to emulsify and stabilize ice-cream, yogurt, sauces and syrups(糖水)

31. Vitamins • Vitamin Cfor fruit juices • Vitamin Bfor enriched flour • Vitamin Dfor milk and margarine

32. Minerals & Iodine • Ammonium ferric citrate in infant milk formulations and bread flour • Iodine in iodized salt

33. 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

34. BHA and BHT • BHA(butylated hydroxyanisole) • BHT(butylated hydroxytoluene) • Commonlyused antioxidantsforfat-solublefattyproducts • Similarpropertiesto thenaturalantioxidant,vitamin E

35. O· O· C(CH3)3 C(CH3)3 OCH3 OCH3 BHA and BHT • They appear to work by donating the H atom of the –OH 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. Antioxidant radicals from BHA

36. Allergies • Some people are allergic to certain additives. It is suspected that MSG and Tartrazine may cause rashes, stomach upsets and asthma.

37. Hyperactivity • In the 1970s, it was suggested by some scientists that food additives may be linked to hyperactivity and attention deficient disease (ADD) in children • Some 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

38. 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

39. Controversy over BHA and BHT • Small amount of BHT shown to prevent cancer • Larger amounts can cause cancer

40. Chinese Restaurant Syndrome / MSG Syndrome Side effects of MSG • Some people allergic toMSG • Dizziness • Thirst • Headache • Chest pain • Sweating • Abdominal discomfort

41. 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

42. 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 with secondary amines, which are released during digestion of proteins, to from nitrosamines.HNO2(aq) + R2NH(aq)  R2N-N=O(aq) + H2O(l) Stomach acid Secondary amine nitrosamine

43. Toxicity of Sulphur Dioxide • Sulphur dioxide is poisonous • Attack respiratory system

44. Potentcarcinogenicnatureofsaccharin • Bitter aftertaste which renders it unpleasant to some users • High doses cause cancer

45. 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

46. Legislation in World • In USA • Food and Drug Administration (FDA) is responsible for monitoring the safety, purity, and wholesomeness of food additives • In UK • Food Advisory Committee compiles in European Economic Community, a permitted food additive is assigned a E number.

47. Legislation in World

48. Legislation in Hong Kong • Legislate permissible additives and maximum limits of additives in particular foods • Require supply of information as to composition of substances used in the preparation of food • Check on food labeling • Inspect food- processing industries • Take samples for chemical analyses on foods and food additives • Seize and destroy food • Prosecute for false labeling, advertisement, using non-permitted additives or using additives beyond the permissible limits.