FOOD PRESERVATION - PowerPoint

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					FOOD PRESERVATION




Prepared and revised by:
Ms. Carina B. Salgado
August, 2010
Food Preservation

  Process of prolonging the shelf life of
   food
  Treatment done to food to delay or stop
   food spoilage
Why Preserve Food?

    Deterioration may cause food to be wasted
    Contaminated food can cause illness and in severe
     cases, this is known as food poisoning
    Money is saved when food commodities are kept from
     spoilage
    When food is kept from spoilage, it maintains its
     nutritive value
    It also ensures food is available for use even during
     lean season
    Why don’t you try and add a few points to the
     above reasons. Let’s now find out the effects of
     food spoilage on different food commodities.
The effects of spoilage on the various food
commodities

      Protein food
      They go putrefied when they are contaminated. This is the
       situation where protein foods rot, and produce very bad smell.
      Fats and oils
      They go rancid. This is the condition where food containing fats
       and oils begin to smell and taste bad when they are old.
      Carbohydrates
      Cooked cereals become marshy and slimy when affected by
       micro-organisms. This condition is known as serenasis. Flour
       products smell and taste unpleasant when they are spoilt. They
       are described as being stale.
      Fruits and vegetables
      They rot, ferment and decay.
Food Spoilage

    Food spoilage means the original
     nutritional value, texture, flavor of the
     food are damaged, the food become
     harmful to people and unsuitable to eat.
Types of Food Spoilage

  Microbial – moulds, yeast and bacteria
  Macro – biological – infestation, rodents
   etc.
  Chemical - enzymes
  Autolysis – self decay/decomposition
  Physical Damages caused by
   mishandling and negligence
The Chain of Food Spoilage
         growing                                  processing


                                              Often air dried
  Subject to wildlife                         under minimal
   contamination            harvesting
                                                  cover
 Correct temperature
 for microbial growth                        Prone to moulds if
                         Gathered in the
                                              damaged during
                              wild
   Dust, moisture                               harvesting
     collection            Uncontrolled
   Poor irrigation
                        storage conditions

                          Rodents and
                            insects
Microbial decomposition




                Fungus
Microbial Spoilage




            Moldy   bread
Microbial decomposition




 Moldy Meat Loaf   Potato with Fungus
Yeast
Microbial decomposition
Spoiled Meat
Maggots
Autolysis
Chemical Spoilage
Macro-biological
Macrobiological
Physical
Physical Damage
Principles of Food preservation

    Prevention or        delay    of    microbial
     decomposition
      Asepsis        –process     of       keeping
       microorganisms out of food and its
       surroundings
      Removal of microorganisms

      Hindering    the growth and activity of
       microorganisms
      Killing microorganisms by heat or irradiation
   Prevention    or     delay              of    self
    decomposition of food
       Destroying or inactivating food enzymes
            Using of heat like blanching
       Preventing oxidation with the use of anti-
        oxidants
   Preventing    insects,      animals and
    mechanical causes from spoiling food
    with the use of proper facilities for
    handling, packaging and storage,
    transport and distribution.
Methods of Food Preservation

 Drying
 Salting
 Curing
 Smoking
Methods of Food Preservation

  Freezing and refrigeration
  Canning
  Sugar Preservation
  Pasteurization
  Packaging
Group Work (by committee)

    Given the assigned method:
      Discuss in your group its underlying
       principle
      State the preserving agents needed and its
       specific function
      Possible advantages and disadvantages

      Products

				
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posted:8/9/2012
language:English
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