Monday, 11 July 2016

FOOD PRESERVATION AND STORAGE

DEFINITION : Food preservation is defined as a means of keeping foods for longer periods than would naturally be possible without destroying it's nutrients.

 THE FACTORS RESPONSIBLE FOR FOOD WASTAGE 
 • Rodents, Insects, Monkey, Microorganisms e.g bacteria, yeast and moulds and spoilage.


 AIMS OF PRESERVING FOOD 

 • Destroy the agent responsible for food spoilage
 • Arrest enzymatic activities on food
• Prevents entry of new microorganisms during storage .

 THE IMPORTANCE OF PRESERVING FOOD 
 • It make foods available all the year round.
 • Food is not wasted due to spoilage.
 • Food poisoning is prevented.

 THE DISADVANTAGES OF IMPROPER PRESERVATION OF FOOD 
 • Food wastage.
 • Food poisoning
 • Scarcity of food.

 THE VARIOUS METHODS OF PRESERVING FOOD 
 (1)  Application of heat

     e.g. -Boiling and frying for meat and fish
             -Pasteurization for canned food.
             -Sterilization for canned food.

 The food in these methods are subjected to a high temperature and held at this temperature for varying methods. The enzymes are destroyed and micro-organisms are killed. Also excluding air and sealing of containers in canned foods prevents re-contamination.

(2) Dehydration (Removal of water content) 

e.g. - Sun drying for fruits and Vegetables
        - Smoking for meat and fish. In this method, the water content in food is reduced And consequently made unavailable for micro organism to grow and cause spoilage.

(3) Pickling (Addition of salt or Sugar) 
 Sugar or salt are added to give a concentrated solution in which micro organism become dehydrated and die. Examples of foods preserved in this method are meat, jams, etc.

(4) Refrigeration and Freezing In this method n micro organisms cease to grow or grow only very slowly at low temperature E.g. refrigerators temperature at 5-7C can store daires, fruits and vegetables for short periods only and deep freezers at 18 degrees centigrade or below will store meat and fish for long periods.

(5) Fermentation : Garri, fufu, locust beans are product of fermentation and can be kept in this for a long period of time.

(6) Oil : Can be used to preserve food e.g. fried meat can be covered with oil and kept for a long period of time.

(7) Chemical Preservatives : e.g. Vinegar is used to preserve fruit and vegetable, sulphates for sausages, fruit juices, wine and jams; and benzonic acid for soft drinks.

(8) Spices e.g. pepper is used to store beans in air tight containers.

(9) Burying: Is another method of preserving food e.g. yam, cassava, and potatoes can be hidden under ground and buried till required.

(10) Another method used in preserving food in the greenery (Rhombus) grains are well dried and kept there till needed.
zealmatblog

No comments:

Post a Comment