5.2 Food Preservatives
Transcript of 5.2 Food Preservatives
Chapter 5 Chemicals for Consumers
B. FOOD ADDITIVES
• A natural or synthetic substance which is added to food to prevent spoilage or to improve its appearance, taste or texture
Types of Food Additives
Preservatives
Antioxidants
Flavourings
Stabilizers
Thickeners
Dyes
Preservatives
• Substances added to food to slow down or prevent the growth of microorganisms.
• Examples:
Salt, vinegar, sugar, sodium benzoate, sodium nitrate, sulphur dioxide
Preservative Example How it works
Salt Salted fish Draws the water out of the cells of microorganisms and retards the growth of microorganisms Sugar Jam
Vinegar Provides an acidic condition that inhibits the growth of microorganisms
Sodium nitrate or sodium nitrate
Burger, sausage, launcheon meat
Slow down the growth of microorganism
Benzoic acid or sodium benzoate
Sauce
Sulphur dioxide Fruit juice
Antioxidants
• Added to food to prevent oxidation that causes rancid fats and brown fruits.
• Examples:
butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), ascorbic acid (Vitamin C), tocopherol (Vitamin E) and sodium citrate
Antioxidant Example Function
Butylated hydroxyanisole (BHA)
Butylated hydroxytoluene (BHT)
Margarine To retard rancidity in oils
Ascorbic acid (Vitamin C) Fruit juice To preserve the colour of fruit
juice
Alpha tocopheral (Vitamin E)
Protects body tissue from damage caused by substances
called free radicals
Sodium citrate Cooked cured
meat To stop fats from turning
rancid
Flavouring
• Used to improve the taste of food and restore taste loss because of processing
• Examples:
Sugar, salt, vinegar, monosodium glutamate (MSG), aspartame and synthetic essences
Stabilizers
• Substance which helps to prevent an emulsion from separating out
• Examples:
Lecithin, mono- and di-glycerides of fatty acids
Thickeners
• Used to thicken foods
• Examples:
Pectin (jams and jellies)
Acacia gum (chewing gum, jelly and wine)
Gelatine (yogurt)
Dyes
• Used to add or restore the colour in food
• Examples:
Tartrazine, anthocyanin,
Advantages and Disadvantages of Using Food Additives
Advantages Disadvantages
Make food stay fresh longer, look nicer and taste better
Associated with serious diseases like cancer and asthma
Make food last longer Toxic effect