FOOD PRESERVATION
Food preservation can
be defined as the science which deals with the process of preservation of decay
or spoilage of food, thus allowing it to be stored in a fit condition for
future use. The process used varies with the length of storage intended. It may
be as simple as boiling milk so that it may keep for 24 hours or pickling of
mango or lemon where the intended period of storage may be as long as a year.
IMPORTANCE OF FOOD PRESERVATION
Food supply has to keep
pace with the needs of the population. There is always a shortage of food in
developing countries like India because of the demands of the increasing
population. Interesting food production to meet this shortage results in
wastage due to inadequate facilities available for shortage and preservation.
It is therefore, important to improve and expand facilities for the shortage
and preservation of food. Preservation of food helps in:
- Increasing the shelf-life of foods thus increasing the supply.
- Making the seasonal food available throughout the year.
- Adding variety to the diet.
- Saving time by teaching preparation time and energy.
- Stabilizing prices of foods.
- Improving the nutrition of the population.
Preservation increases
availability of foods, thus improving the nutrition of the people. Availability
of seasonal foods throughout the year also helps in stabilizing prices of such
foods.
CAUSES OF FOOD SPOILAGE
Food spoilage usually
refers to undesirable changes occurring in food due to the action of
microorganisms, insects and enzymes. Foods vary greatly in the length of time
for which they can be held in their natural form without spoilage. For purposes
of food preservation, foods are classified as perishable, semi-perishable and
non-perishable. Perishable foods such as milk, meat, sea foods and many fruits and vegetables
begin to deteriorate almost immediately after harvest if not preserved. These
foods have a high moisture content and are highly susceptible to spoilage.
Foods are spoiled by the action of:
(i)
Microorganisms,
(ii) enzymes, and (iii) insects.
Spoilage by Microorganisms
The microorganisms that
cause food spoilage are moulds, yeasts and bacteria. Some of these organisms
can be used to produce desirable changes in food under controlled conditions
such as the formation of curd (dahi) from milk. However, they are more often
agents of spoilage. Some microorganisms can exist both in vegetative and spore
form. Spores are more resistant to destruction by heat or other agents than the
vegetative form.
Moulds: Mould
growth on foods with its fuzzy or cottony appearance is familiar to everyone
and foods with such growth on them are generally unfit to.
Spoilage by Insects: Worms, bugs,
weevils, fruit flies, a moths may damage food and reduce its nutrients content
and render it unfit for human consumption.
Means of preservation: Preservation of food can be achieved by chemical,
biological, or physical means.
- CHEMICAL PESERVATION: It involves the addition of substances such as sugar, salt and acid, or exposure of food to chemicals such as smoke or fumigants.
- BIOLOGICAL PRESERVATION: it involves alcoholic or acidic fermentation.
- PHYSICAL PRESERVATION: it involves using methods which include temporary increases in the product’s energy level (heating and irradiation) , controlled reduction in the product’s water content ( concentration, air-drying, freeze-drying) and use of 0f protective packages.
No comments:
Post a Comment