Food commodities contain various nutrients which are useful to the human body for the performance of its various functions. Unfortunately, this reason also makes food easily susceptible because these nutrients which are useful to man are also useful to micro-organisms which grow on our food, consume them and make the leftovers unfit for human consumption.
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Hence, food preservation is treating food in such a way that it will be kept in good condition for a long period.
REASONS FOR PRESERVING FOOD
- To prolong its shelf life.
- To prevent its spoilage to prolong its shelf life.
- To avoid wastage especially when they are in season.
- To allow foods in the off-season to be used.
- To have a variety of food available for an emergency.
- To eliminate the purchase of food when they are most expensive.
- To introduce variety into the family menu.
CAUSES OF FOOD SPOILAGE
Food spoilage usually refers to undesirable changes taking place in food which eventually leads to rejection and therefore to wastage. The following are the causes of food spoilage.
- Actions of micro-organisms e. g. bacterial yeast and Moulds.
- Food enzymes.
- Chemical reactions in the food.
- Physical changes due to freezing burning, drying, pressure and so on.
CLASSIFICATION OF FOOD SPOILAGE
Food can be classified into three major groups
- PERISHABLE FOOD OR HIGH-MOISTURE FOODS: – These are foods which begin to spoil almost immediately unless preserved in some ways because of their high-water content. Examples of such foods are milk, meat, fish, sea foods, fruits and vegetables.
- SEMI-PERISHABLE FOODS OR INTERMEDIATE MOISTURE FOODS: – These are foods which can be kept for some time before going bad. Their water content is low. Examples of such foods are root vegetables and tubers.
- NON- PERISHABLE FOODS OR LOW-MOISTURE FOODS: – These are foods which can be kept for a reasonably long period without getting spoilt due to their low water content. Examples are nuts, dried legumes and cereals.
The most obvious difference between foods in these three groups is their water content which is high in perishable foods. The firm covering foods such as nuts, cereals and legumes also offers protection.
- state the principle underlying food preservation.
- Mention the causes of food spoilage.
- Explain perishable foods with examples.
mention and explain types of home drying.