FOOD ADDITIVES.pptx

FOOD ADDITIVES  LEARNING OUTCOMES At the end of this topic, students will be able:  To identify the what are food additives.  To understand the reasons why food additives are used.  To understand the different sources of food additives.  To understand the different role...

FOOD ADDITIVES  LEARNING OUTCOMES At the end of this topic, students will be able:  To identify the what are food additives.  To understand the reasons why food additives are used.  To understand the different sources of food additives.  To understand the different roles and functions of food additives in food.  To ascertain the health implication due to the consumption and use of food additives.  What are Food Additives? Some of the food we eat are fresh (i.e. unprocessed). Most foods, however, are processed. In food processing , small amounts of certain chemicals are often added. These are called food additives. Added to food product either directly or indirectly during processing, storage or packaging.  What are Food Additives? “ Defined legally as any substance not commonly regarded or used as a food, which is added to or used in or on food at any stage to affect its keeping qualities, texture, consistency, appearance, taste, odour, alkalinity or acidity or to serve any other technological function in relation to food.” Why do we use food additives?  What is E-Number? Additives approved for use in the European Union (EU). These additives have E- numbers. The E-numbers tell us “What the additive is used for”. E-Number Use E 100-199 Food Colours E 200-299 Preservatives E 300-399 Antioxidants E 400-499 Emulsifiers & Stabilisers E 500-599 Anticaking agents E 600-699 Flavourings & Flavour enhance  TYPES OF FOOD ADDITIVE Natural – found naturally, such as extracts from beetroot juice (E162). Nature-identical – synthetic identical copies of substances found naturally, such as benzoic acid (E210). Artificial – produced synthetically and not found naturally, such as nisin (E234).  1. PRESERVATIVES Prevent the growth of micro-organisms which could cause food spoilage and lead to food poisoning. Extend the shelf-life of products sold to the consumers. Examples- Natural preservatives such as vinegar, salt, sugar and artificial preservatives such as Sodium benzoates, Sodium nitrite/nitrate, sulphites etc.  1. PRESERVATIVES Chemical agent Mechanism of action Foodstuffs Maximum Limit Acetic acid disrupts cell membrane function (bacteria, yeasts, some mayonnaise, pickles 3.6% (vinegar) molds) Benzoic acid, disrupts cell membrane function/inhibits enzymes (molds, beverages, fruit juices, Benzoate yeasts, some bacteria) soft drinks 0.05-0.1% natamycin binds sterol groups in fungal cell membrane (molds, Cured cheese yeasts) Sorbic acid Cheese, wine, baked Inhibit mold and yeast product 0.3% 150-200 ppm nitrates, inhibits enzymes/disrupts cell membrane function nitrites (bacteria, primarily Clostridium botulinum) Cured meat  2. ANTIOXIDANTS Prevent oxidative rancidity in foods high on fats and oils. Vitamins and various amino acids can easily be destroyed by exposure to air, and antioxidants serve to protect them. Prevents the browning of cut fruits, vegetables and fruit juices i.e. increase shelf- life and appearance.  There are 2 types of antioxidant: -Water soluble -Fat soluble 2. ANTIOXIDANTS  3. COLOURS Added to foods to replace lost colors during processing or storage, or to make foods look more attractive, appetizing and saleable. Simulate the senses of consumers to perceive food as natural. Natural colorants are Caramel coloring (E150), Annatto (E160b), chlorophyll (E140), Cochineal (E120), Betanin extracted from beets, Turmeric (curcuminoids, E100), Grape Skin Extract etc. Synthetic colorants are FD&C Blue No.1 (E133), FD&C Green No.3 (E143), FD&C Red No. 40 (E129) etc.  4. FLAVOURING AGENTS AND FLAVOUR ENHANCERS Flavouring agents impart flavours, namely taste or odour or both to food. Examples-Natural flavouring agents such as spices and their extracts, herbs, roots, essence and essential oils. Flavour enhancers are not flavours themselves but bring out the flavour in foods. Examples – Artifical flavours such as MSG and natural flavours e.g extracted from milk, egg, nuts etc. 4. FLAVOURING AGENTS AND FLAVOUR ENHANCERS Monosodium glutamate is a white solid. It possesses no flavor of its own, but it can ‘bring out’ the flavor of foods. It is therefore a flavor enhancer. Some common flavouring agents Monosodium glutamate (MSG)  5. ANTICAKING AGENTS Placed in powdered or granulated foods to prevent them from caking or sticking. Ensure free movement or flow of other powders, e.g. in dried milk or table salt. Function to readily absorbing excess moisture -By coating particles to impart a degree of water repellency Useful in complex powdered mixes and certain spices that contain free essential oils  5. ANTICAKING AGENTS Foodstuffs Anti-caking agents Maximum limit Instant mixes, RTD Carbonates of calcium and 2% beverages, processed magnesium cereal goods Powdered soft drinks, Sodium aluminium silicate 0.5% concentrate mix/fruit beverage drink, 1% powdered sugar Baking powder, Calcium silicate 5% , table salt 2% Grated or shredded cheese Microcrystalline cellulose powders  5. ANTICAKING AGENTS Example: Sodium bicarbonate (E500) or baking soda.  6. ANTIFOAMING AGENTS Antifoaming agents reduce or prevent foaming in foods. Help reduce surface tension and thus rupture bubbles. These agents are included in many foods, such as Diet Pepsi, Diet Coke, and Sprite. Added to cooking oils to prevent excessive frothing during deep frying. Example-Dimethyl polysiloxane (silicone, silicone oil, dimethyl silicone) (max. 10ppm).  7. EMULSIFIERS Emulsion consists of two immiscible liquids (oil & water), with one of the liquids dispersed as small spherical droplets in the other. Two types of emulsion: -Water-in-oil (w/o): margarine, butter, spreads etc. -Oil-in-water (o/w): mayonnaise, salad dressings, milk, beverages, cream, soups, sauces etc. Emulsifiers allow water and oils to remain mixed together in an emulsion. Reduce the surface tension at the interface of two normally immiscible phases.  7. EMULSIFIERS There are two parts.  a polar group with an affinity for water (hydrophilic), and  a nonpolar group with an affinity for oil (lipohilic). 7. EMULSIFIERS  7. EMULSIFIERS Lecithin are also obtained from soybeans  8. STABILIZERS Help to stabilize emulsions or maintain homogenous dispersion of two or more immiscible substances in foodstuffs. Examples of stabilizers are agar, acacia gum, pectin, alginic acid, gelatin, calcium chloride etc.  9. THICKENERS Increases the viscosity of food with out substantially modifying its other properties. Its help give food body. Example of thickeners are polysaccharides, such as cornstarch, potato starch, carboxy methylcellulose, pectin; vegetable gums (guar gum, acacia gum, and xanthan gum), protein (proteins used as food thickeners include collagen, egg whites etc.)  9. THICKENERS  Sauces, gravies, pie fillings, cake toppings, chocolate milk drinks, jellies, puddings and salad dressings, are among the many foods that contain stabilizers and thickener.  10. GLAZING AGENTS Provide a shiny appearance or protective coating on the surface of food such as confectionary. Appearance and shelf-life. Example-Stearic acid (E570), Beeswax (E901), Candelilla wax (E902)  10. SWEETENERS Improve the taste and flavour of foods. Natural Sweeteners found in sugar cane, maltodextrins, sugar beet or corn syrup. Artificial sweeteners such as aspartame, acesulfame K, sugar alcohols, sucralose, saccharin etc.  beneficial effects for diabetes mellitus, prevent tooth decay and low/zero energy (calories) High Intensity sweeteners, e.g. saccharin, cyclamate, acesulfame-K , aspartame, have a sweetness many times that of sugar.  used in small amounts, e.g. in diet foods, soft drinks, sweetening tablets. Bulk sweeteners, e.g. sugar alcohol (sorbitol) and fructo oliogosaccharide, have a similar sweetness to sugar and are used at similar levels. 10. SWEETENERS  10. ACIDULANTS Food acids are added to make flavours "sharper“. Act as preservatives and antioxidants. Examples- vinegar, citric acid, tartaric acid, malic acid, fumaric acid, and lactic acid.  11. CHELATING AGENTS Serve as scavengers of metals which catalyze oxidation. Examples - EDTA (ethylenediamine tetraacetic acid) and citric acid.  12. CURING AGENTS These are additives used to preserve (cure) meats. Give meat desirable colour and flavour.  Inhibit the growth of microorganisms and prevent toxin formation. Example- Sodium nitrite is used as a preservative and colour stabilizer in meat and fish products.  nitrite, when added to meat, gets converted to nitric oxide, which combines with myoglobin to form nitric oxide myoglobin (nitrosyl myoglobin), which is a heat- stable pigment.  13. HUMECTANTS Humectants prevent foods from drying out by retaining moisture. Examples – Glycerol/propylene glycol (E1520), and glyceryl triacetate (E1518), sorbitol (E420).  14. FIRMING AGENTS Keep the tissues of fruits and vegetables crisp. Examples: Aluminium sulphates and calcium salts.  15. CLARIFYING AGENTS Remove haze or sediments in drinks such as in beer, wine and fruit juices. Phenols, tannins; proteins and pectic substances combine with polyphenols to form haze. Examples: bentonite, gelatins, isinglass, synthetic resins (polyamides and polyvinylpyrrolidone PVP) are used to remove haziness or sediments and oxidative deterioration products in fruit juices, beers and wines. 15. CLARIFYING AGENTS  Advantages of food additives Extend the life of processed foods so they can be transported, stored or kept on the shop shelf for longer. Maintain a standard quality. Make the products more attractive to the consumer. Disadvantages of Food Additives Disadvantages of Food Additives Disadvantages of Food Additives Disadvantages of Food Additives Disadvantages of Food Additives Disadvantages of Food Additives