FFT LEC unit 1

• Water, carbohydrates, proteins, fats as well as vitamins, and trace

  minerals

  COMPOSITION OF FOOD
• All Food components are chemically reactive
• tannins - widely distributed in plant tissues
• Any substance, whether processed, semi-processed or raw, which is

  intended for human consumption

  FOODS
• First step taken to change a food source to food

  Primary Food Processing
• Step further where post harvest food may no longer have semblance to the original source

  Food Manufacturing
• Procedures of food preparation steps –change the food source

  Food Processing
• Non-enzymatic browning - series of complex reactions that lead to the production of brown color, loss of nutritional value


  Maillard Reaction
• Browning pigments formed are called melanoidins
• the presence of O2, PPO can oxidize polyphenols (colorless) to quinones (yellow to brown)
• Caused by family of enzymes, polyphenol oxidases (PPO)

  Enzymatic Browning
• Development of rancidity in fatty and oily food

  Oxidation Reactions
• Biological nature: food deteriorates immediately after harvest, catch or slaughter

  Deterioration of Food
• aesthetic appeal


  Loss of organoleptic desirability
• egg white on storage: reduced foaming ability

  Loss of functionality
• ascorbic acid or B vitamins on exposure to light or heat


  Loss of nutritional value
• can lead to illness or even death

  Loss of safety
• All ‘conspire’ to cause spoilage


  Causes of Deterioration
• Complex combinations and reactions of these substances perform specific functions

  Causes of Deterioration