This article throws light upon the top household methods for preserving food. The six household methods are: 1. Refrigeration 2. Heating 3. Canning 4. Pickle and Jam 5. Drying 6. Using chemical preservatives.
Microorganisms though not readily destroyed by severe cold are less active at low temperatures. Refrigeration is widely used at homes and in commercial plants as a means of maintaining the low temperature for the storage of perishable foods.
Food is also preserved through the application of heat. The heat is applied at very high temperatures. The food stuff heated in containers or by others means to a temperature below the boiling point of water for definite period is known as pasteurization.
This helps in two ways:
a. Destroys pathogenic organisms associated with food and
b. Extends the product’s shelf life by decreasing the microbial population and inactivating certain enzymes.
Example of pasteurization could be milk.
Another method of heat treatment is blanching which is usually performed by dipping the products in boiling water for two or three minutes.
Canning is the procedure of placing food stuffs in scalable containers, which involves the steps closing [sealing] heating and cooling. Large amounts of food are canned which include a wide variety of fruits, vegetables and fleshy foods.
This is the age old method of preserving foods. By the use of preservatives like salts, vinegar, the goods were preserved in ancient time which continues to the present day. Salt is considered as a valuable preservative and used in pickling. Salt helps to remove the moisture. Sugar is also used as preservative in a few varieties of pickles. Jams are usually fruits preserved in the form of pulp by the addition of sugar, fruit pulp and chemical preservatives like Sodium benzoate, potassium metabisulphate, citric acid, etc.
Drying is also an ancient method of food preservation. Drying is a natural method of food preservation. Drying is the process by which the moisture content of foodstuff is removed. Drying has a very good advantage, i.e. due to removal of water microorganisms would not grow as moisture is important for the growth of microorganisms. Many fruits and vegetables are preserved by this method too.
Certain chemicals are used as preservatives, which retard the growth of Microorganisms by increasing or decreasing the pH of food for their survival. The common chemical preservatives used are potassium meta-bisulphate, sodium, benzoate, citric acid, vinegar, etc.
Freezing certain foods can be a good method of food preservations. Though the freezing procedure does not destroy microorganisms, it stops their growth. Fruits, vegetables, meat, fish, poultry can be preserved by this method.