Food processing , preservation and storage

Common food processing techniques include:

1. Removing unwanted outer layers e.g. peeling potato
2. Chopping or slicing e.g. bananas, mangoes and cassava
3. Liquefaction e.g. producing juice by squeezing fruits
4. Fermentation e.g. making wine from bananas or grapes, beer brewing
5. Cooking e.g. boiling, frying, steaming or grilling
6. Deep freezing
7. Baking

This involves special methods of food processing that are used to prevent food from getting spoiled or going bad.

These methods include:

1. Canning or bottling: used to eliminate micro-organisms
2. Pasteurization and boiling: uses high temperature to kill micro-organisms
3. Refrigeration: using low temperature to slow the growth of micro-organisms
4. Irradiation: uses radiation to kill micro-organisms
5. Drying, salting, applying honey or smoking to eliminate moisture
6. Adding chemicals such as salt, sugar and carbon monoxide to prevent spoilage

1. Prevents wastage of food
2. Saves money by preventing spoilage
3. Maintains the quality of food
4. Prevents the growth of harmful micro-organisms
5. Removes harmful toxins and improves flavor
6. Makes food available even out of season
7. Enables transportation of delicate food like milk and fruits

Curing

Involves adding substances like sugar, salt, vinegar or spices to animal foods such as meat and fish. It removes water and improves taste.

Drying in the sun

Food is left in the sun to reduce moisture content. Used for drying rice, maize, beans, cassava, etc.

Smoking

Smoke reduces moisture to prevent micro-organism growth. Used for grains, meat and fish.

Cooking

Includes boiling, steaming, baking, grilling. Softens food and improves flavor. Example: meat can be grilled or deep-fried.

Salting

Salt removes water from food and kills micro-organisms.

Fermentation

Conversion of sugars into acids or alcohol. Example: milk into yoghurt, mangoes in salty water for pickling.

Pasteurization

Heating food to a high temperature for a short time. Used for milk and juice.

Liquefaction

Making liquids from solid food, mainly fruits. Juice is pasteurized and stored.

Canning and bottling

Food is sealed in vacuum-tight containers and heated to kill micro-organisms. Used for juice, beans, fish, beef.

Using additives

Adding chemicals like sodium benzoate or vinegar to slow microbial growth. Used in meat and fish.

Drying or dehydration

Food is dried using hot air or freeze-drying and sealed in moisture-proof containers.

Irradiation

Using radiation energy to stop the growth of micro-organisms. Used in onions, beans and potatoes.

Food storage

Food storage is the method of keeping reserves for future use. This can be done at family level or large scale by government.

Storage in granaries and pits

Grains are dried and stored in raised granaries. Mixed with neem ash to prevent pests.

Storage in pots and tins

Preserved food like flour and dried vegetables are stored in dry pots or sealed containers.

1. Simple and usable by most people
2. Uses local materials and affordable
3. No harmful chemicals
4. Enhances taste through methods like smoking
5. Retains most nutrients

1. Food lasts for short periods
2. Difficult for large scale use
3. Limited variety of food types

Refrigeration

Storing food at around 4°C to slow microbial growth. Used for milk, juice, vegetables.

Freezing

Storing food below –10°C to stop microbial growth. Used for meat, fish and poultry.

1. Food lasts months or years
2. Handles a large variety and quantity of food
3. Fast and efficient technology

1. Chemicals can be harmful if overused
2. Some methods require electricity
3. Expensive equipment needed
4. Some nutrients may be lost