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Sample Question:-

Sample Question:- Explain, with an example of each, the function of preservatives and flavour enhancers. (4 marks). WHAT: To learn how to CLASSIFY additives according to their properties. EXPERT Evaluate how additives are used, suggest replacement ingredients in food products. HOW:

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Sample Question:-

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  1. Sample Question:- Explain, with an example of each, the function of preservatives and flavour enhancers. (4 marks) • WHAT: • To learn how to CLASSIFY additives according to their properties EXPERT Evaluate how additives are used, suggest replacement ingredients in food products • HOW: • Watching a video • Looking at the key properties that I need to focus on for the specification • Answering some questions ASPIRE Analyse the reasons why additives are used in food products Food Additives - Specification Cholesterol lowering spreads, fortification, fortified foods, positive and negative effects of colourings, emulsifiers, stabilisers, flavourings, preservatives WHY: To be able to answer an exam question effectively CHALLENGE Categorise the different food additives

  2. FUNCTIONS IN THE DIET • Additives provide functional properties in foods. • This can be to give physical, sensory, storage or nutritional characteristics. • Additives may be used to satisfy more than one of the above functions. • i.e vitamin C is used as a vitamin and for its antioxidant properties.

  3. ADDITIVES • Additives prefixed by an “E” are approved by the EU. • Additives can be either natural or synthetic.

  4. CHOLESTEROL LOWERING SPREADS The ingredients work with the body by partially blocking the entry of cholesterol into the bloodstream. It is claimed they lower bad cholesterol, known as LDL, by up to 15 per cent when used every day as part of a healthy diet and lifestyle

  5. PHYSICAL PROPERTIES • An additive might be used to make a product :- • Thicker and gelled • Made more or less acid • Aerated with gas bubbles • Emulsified

  6. THICKENING OR GELLING • Hydrocolloids are substances capable of holding large quantities of water in their structure or joined to their molecules. • Many substances have these properties, carbohydrates such as starch, pectin, many gums and gelatin are examples. • The main sources of starch are maize and wheat.

  7. MODIFIED STARCH • It is possible to breed different ratios of the two starch compounds amylopectin and amylose. • This can speed up the gelatinisation process. • Unmodified starches can hydrate and swell rapidly but then lose viscosity(thickness) on standing. • Starches can be modified to improve thickening, binding, stability, gelling and mouthfeel.

  8. PRE-GELATINISED STARCH • This is gelatinised by heating with water and then spray dried. • The powder produced will produce a starch gel instantly when cold water is added. • This is useful in the production of cold desserts.

  9. GUMS • A number of gums have useful thickening and gelling properties. • These include alginates, celluloses, xanthan, pectins, carrageenans and tree gums such as arabic (acacia). • All will thicken products, some will stabilize products to prevent oil separation. • Eg salad dressings, thickening, quick whipping properties, milk shakes, mouthfeel.

  10. GUMS

  11. ACIDITY CONTROL • Some products need their acidity increasing or decreasing to improve their palatability. • Acetic acid (vinegar), tartaric acid (used in baking) and calcium citrate (soft drinks) are examples.

  12. EMULSIFIERS AND STABILISERS • These additives prevent foods from splitting into watery and fatty layers. • An emulsifier enables an oil to be dispersed in a liquid without it separating. • Eg mayonnaise, soup, sauces • A stabiliser is used to bind large quantities of water into a stable form. • Eg ice cream

  13. SENSORY PROPERTIES • To be successful foods must have an appealing taste smell, mouthfeel and appearance. • In Britain until recently the trend has been to consume coloured foods. • This has recently reversed and many consumers seek out naturally coloured foods.

  14. SENSORY PROPERTIES • There are around 3000 food flavouring substances. • The majority do not have an “E” prefix because they are natural substances. • Flavourings are odours detected by the nose. • Our mouth is only capable of tasting salt, sour, bitter and sweet flavours.

  15. SENSORY PROPERTIES • On food labels, flavours must be correctly described • Raspberry-flavour yoghurt has no raspberry in it at all • Raspberry flavoured yoghurt must have some real raspberry in it • Raspberry yoghurt must be made with real raspberries

  16. SENSORY PROPERTIES

  17. FLAVOUR ENHANCERS • Some additives are used to improve the flavour of other substances or to modify or mask undesirable flavours. • MSG is the most common flavour enhancer. • MSG stimulates the taste buds in the mouth. • Over consumption can cause dizziness, sickness and nausea.

  18. SWEETENERS • Saccharin has been used for many years as a sweetener. • Aspartame is used in diet drinks. It is made from two amino acids, aspartic acid and phenylalanine. • Acesulfame is also used.

  19. COLOURS • Colourings are sometimes used to improve a products visual appeal. • They can be used to restore colours in processed food. • Some dyes such as tartrazine (E102) have recently become unpopular due to some consumers suffering adverse reactions. • Some colours such as lycopene (from tomatoes) are natural.

  20. COLOURS • Colourings are sometimes used to improve a products visual appeal. • They can be used to restore colours in processed food. • Some dyes such as tartrazine (E102) have recently become unpopular due to some consumers suffering adverse reactions. • Some colours such as lycopene (from tomatoes) are natural.

  21. SHELF LIFE • Preservatives help to extend a products shelf life over a longer period than normal. • This can help reduce food waste and the risk of food poisoning to consumers. • Fats oils and foods containing them are subject to oxidation which results in rancidity. • UV rays, copper and iron accelerate this. • Antioxidants are added to prevent rancidity.

  22. SHELF LIFE • Some antioxidants stop chemical reactions which cause rancidity, some remove oxygen from the product. • Hydrolytic rancidity cannot be prevented in butter as it is caused by the presence of water. • Examples of antioxidants are ascorbic acid (E300) – used in fruit juice and propyl gallate (E310) - used in vegetable oils and chewing gum.

  23. FORTIFICATION • This group includes minerals, vitamins and protein supplements. • Some nutrients are added by law ie A and D is added to margarine. • Breakfast cereals have many nutrients added such as vitaminC, B6, D, B1, B2, folic acid, iron and niacin.

  24. ADDITIVE NUMBERS

  25. INTOLERANCE TO ADDITIVES • Caffeine: linked to peptic ulcers, insomnia, nervousness and birth defects. • Monosodium Glutamate (MSG): linked to headaches, tightness in the chest, and a burning sensation in the forearms and back of the head. • Nitrite and Nitrate: Meat preservatives that can form powerful cancer causing chemicals when heated. • Saccharin: linked to cancer in laboratory animals.

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