FFT LEC unit 3 & 4

• Refers to storage of foods at temperatures above freezing, at the range 15° C to 1° C


  REFRIGERATION / CHILLING
• Slows down the growth & reproduction of food spoilage microorganisms

  REFRIGERATION / CHILLING
• Retard loss of nutritive value
• Retardation of growth of microorganisms
• Refrigerated food will last longer if it is cleaned
• It will not destroy microorganisms or inactivate enzymes

  FREEZING
• Inhibits the activities of microorganisms

  FREEZING
• Large ice crystals become even bigger (fluctuations)

  Recrystallization
• Slow freezing, outside cell; fast freezing, inside cell

  Ice Crystal Location
• 9%

  Volume Increase
• non-water component

  Concentration
• Exposure to cold air temperature ranging from -18 to -40 degrees Celsius

  Air Freezing
• Foods are placed about 2-10 cm deep

  Fluidized Bed
• Contact Freezing

  Plate Freezing
• Product is embedded in a block of ice

  Block Freezing
• Immersion of food in the refrigerant, most common is liquid nitrogen

  Immersion Freezing
• Applying a coat of ice over the frozen food which acts like a skin (0.25-0.50 cm thick)

  Glazing
• 4C & 40F

  Chilling Storage
• -18C & 0F

  Freezer Storage
• is not the adverse process to freezing due to the different physicochemical properties of water and ice

  THAWING
• During thawing, there are significant drip loses, which can offer an ideal substrate for enzyme activity and microorganism growth
• Chilling Storage of Bacon

  7 days
• Chilling storage of fresh chicken

  1-2 days
• Process of removing water from food

  DRYING & DEHYDRATION