Food Purchasing, Processing, Preserving and Safety – JSS2 Home Economics Lesson Note (Third Term)

Food preservation is caring for or treating food so that it stays in good condition for a long time. Preserved food can be stored longer than raw food. Methods include sun drying, smoking, freeze drying and canning. Preserved or purchased food is then stored safely in suitable facilities such as containers, cupboards, refrigerators and freezers.

Behavioural objectives

By the end of the lesson, students should be able to:

• define food preservation and food storage;
• describe four methods of preserving food;
• name common food storage facilities;
• explain why cold conditions prevent food spoilage;
• state the importance of proper storage of food.

What is food preservation?

Food preservation is caring for or treating food in such a way that it will be kept in good condition for a long period. Preserved food can be stored for a longer period than raw food.

Methods of preserving food

• Solar or sun drying: This is drying by simply spreading the foodstuff in the sun on a mat or concrete floor, e.g. cassava, maize, melon, etc.
• Smoking: Food such as fish, meat and some root crops is preserved by smoking. In some cases, the smoked food items are later sun dried.
• Freeze drying: The water content of the foodstuff is frozen and then sublimed under a vacuum. Heat is supplied by conduction or radiation. Examples of food dried by this method are fish, meat and vegetables.
• Canning: This is the preservation of food by sealing it in air-tight containers and applying heat. It is commonly used for fruits and vegetables.

What is food storage?

Food storage involves keeping preserved or purchased food in a safe condition and in a suitable facility until it is needed for use.

Food storage facilities

• Plastic food containers: They are suitable for storing:
  • liquids, such as palm oil;
  • flour, e.g. cassava, yam and wheat flour;
  • dried grains and pulses, e.g. maize, beans and rice;
  • ground food ingredients, e.g. egusi and ogbono;
  • others, such as sugar, salt, etc.
• Food store: This is a place for storing food. It is often part of the kitchen.
• Food storage cupboards, cabinets and shelves.
• Refrigerators and freezers: Food spoilage can be prevented by storing foodstuffs under cold conditions. This is because the bacteria or microorganisms that cause food spoilage are generally inactive under very cold conditions.

Why is proper storage of food important?

• It prevents food from spoilage.
• It prevents loss of nutrients.
• It helps the homemaker to save money.
• It saves time and energy, because the homemaker does not have to go to the market often.

Evaluation

1. State four methods of preserving food.
2. Outline four storage facilities.
3. State the importance of proper storage of food.

Assignment

Explain why refrigerators and freezers help to prevent food spoilage.