Food Processing Technology

 

 
2.5  Food Processing Technology
 
1. Food processing technology:
 
Technology Method
Cooking Food is processed by heating food using bleaching, frying, grilling, smoking, braising, stir-frying, baking and steaming.
Example
  • Chicken curry
  • Fried fish
  • Grilled chicken
  • Rice
  • Vegetables 
  • Cakes
Fermentation The breakdown of complex substances into simpler substances through bacteria, yeast or other useful microorganisms.
Example
  • Soy sauce
  • Kimchi
  • Tempeh
  • Yoghurt
  • Tapai
Dehydration or Drying Water is removed from food through dehydration or evaporation by drying under the sun, using flame or smoke or in the oven.
Example
  • Dried shrimp
  • Dried squid
  • Dried fish
  • Dried fruits
  • Cereal
  • Mushroom
  • Milk powder
Pasteurisation The liquid is heated to a temperature below its boiling point to kill pathogens and then cooled quickly.
Example
  • Milk
  • Dairy products
  • Fruit juices
Canning

Food is kept in cans which are sterilised and heated to a temperature exceeding 115 °C under high pressure to kill microorganisms and their spores.

The air in the can containing the sterilised food is removed before the can is sealed.

The can is then heated again to kill any remaining microorganisms before being cooled quickly.

Example
  • Meat
  • Soup
  • Beans
  • Fish
  • Fruits
  • Sauce
  • Canned milk
Freezing

Food is kept at a temperature of 0 °C or lower so that it can last longer.

The low temperature in the fridge can

  • stop enzyme action
  • inhibit the growth and reproduction of microorganism
Example
  • Seafood
  • Meat
  • Chicken
  • Fish
Irradiation Food is exposed to ionising radiation such as gamma-ray, ultraviolet rays and X-rays to kill microorganisms.
Example
  • Vegetables
  • Cereal
  • Fruits
Vacuum Packaging

Air is removed completely from the container or plastic bag used to pack the food before the package is sealed tight.

The absence of air in the package prevents the growth of microorganisms in the package and stops food oxidation.

Example
  • Nuts
  • Rice
  • Durian 
  • Vegetables
 
2. Chemical substances used in food processing and impacts on health
 
Chemical substance Functions
Preservative
  • Prevents growth and reproduction of microorganisms
  • Reduces food spoilage
  • Makes food last longer
Example
  • Salt
  • Sugar
  • Vinegar
  • Sodium nitrate
  • Sodium nitrate
  • Benzoic acid
  • Boric acid
  • Sulphuric dioxide
Impacts on health
  • Cancer
  • Allergy
  • Foetal defects
  • Damages liver and kidney
Colouring
  • Adds colour to food 
  • Makes food look more attractive
Example
  • Pandan leaf
  • Turmeric
  • Tartrazine
  • Sunset yellow
  • Carmoisine
Impacts on health
  • Cancer
  • Infertility
  • Food poisoning
  • Damages liver and kidney
Bleach
  • Bleaches unwanted natural colour from food
Example
  • Activated carbon
  • Benzoyl peroxide
Impacts on health
  • Cancer 
  • Food poisoning
Flavouring 
  • Improves the taste of food 
  • Makes food more delicious and fragrant
  • Enhances the natural flavour of food
Example
  • Sugar 
  • Vinegar
  • Vanilla
  • Monosodium glutamate
Impacts on health
  • Cancer
  • High blood pressure
  • Heart diseases
  • Mental retardation in children
  • Damages liver and kidney
Stabiliser
  • Prevents deposition of granules in liquid food
  • Improves texture and thickens food
Example
  • Starch
  • Gelatin
  • Agar
  • Acacia gum
Sweetener
  • Sweetens food and drinks
Example
  • Honey
  • Aspartame
  • Sorbitol
Impacts on health
  • Cancer
  • Diabetes mellitus
  • Allergy
  • Obesity
  • Damages liver and kidney
Antioxidant
  • Slows down the oxidation of fatty food
  • Prevents fruits and vegetables from turning brown
Example
  • Ascorbic acid, Tocopherol
  • Butylated hydroxyanisole
Impacts on health
  • Retards body growth
  • Damages liver and kidney
  • Rash and itchy skin
Emulsifier
  • Emulsifier substances that do not mix 
  • Improves homogeneity, stability and texture of food
Example
  • Lecithin from egg yolk 
  • Pectin
  • Monoglyceride