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The following are some common methods of food preservation
- Salting: Salting is the commonest chemical used in food preservation. Salt destroys bacteria and drains water in food. We can use salt in preserving meat, fish, pepper, tomatoes, locust beans, among others.
- Drying: Water is removed in drying. It is used in the preservation of fruits like coconut, pepper, vegetables, etc. Sun or oven can be used for drying. To hasten drying, the food can be sliced or cut into smaller sizes.
- Smoking: This is done using wood smoke. The smoke contains some chemicals that make bacteria inactive. You can use it for fish or meat.
- Refrigeration and Home Freezing: A refrigerator is needed for this method. A deep freezer can also be used. Fish, meat and milk are most preserved using this method. This method slows down bacterial actions but don’t totally stop it. Food in the refrigerator can last for one or two days, while the ones in the freezer can last for three or more days.
Common Food that Can be Preserved
The stores are a vital part of any commercial kitchen. Did you know that at any given time the stores here can contain up to 900 unique items? Many of which have special storage requirements.
Fortunately, most commodities can be classified into one of three categories, making it easy to sort them ready for proper storage. The three categories are:
- Perishable
- Non perishable
Perishable commodities
Perishable commodities are those commodities which deteriorate quickly when not stored properly. Perishable commodities usually require some sort of refrigerated storage.
Perishable commodities include:
Dairy products and eggs
Dairy products are those commodities, which are derived from or based upon milk, and include creams, yoghurts, butter, cheese and ice cream.
Milk needs to be stored in the refrigerator at a temperature between 3 to 4°C. If stored this way fresh milk will last about 10 days.
Cream, yoghurts, butter, cheese and eggs should also be stored at between 3 to 4°C. The shelf life of these products will vary depending on their method of manufacturing, and you should check individual use by dates on the packaging.
Ice cream needs to be kept frozen at a temperature of -18°C or below.
All dairy products need to be kept well sealed when in storage, otherwise they will absorb flavours from strong smelling foods around them.
Meat and poultry
Meat and poultry should be stored between 1 and 3°C. All meat and poultry should be stored on clean trays and covered with plastic wrap. You should never store raw and cooked foods on the same tray.
Meat can be stored in the cool room for 4-6 days, or if vacuum-sealed up to 12 weeks. Poultry can be kept for 3-4 days. If frozen, meat and poultry can be kept for up to six months.
Cooked foods and leftovers
These are also considered perishable and should be stored in the cool room. Cooked foods should be covered before storage and need to be stored separate from raw foods and never on the same tray.
Fruit and vegetables
Fruit and vegetables vary in their storage requirements, but as a general rule most fruit and vegetables should be stored. Lettuce should be stored in the cool room, where the temperature is below 5°C.Root vegetables, such as carrots, potatoes and onions are classed as semi-perishable and do not require refrigeration.Frozen vegetables and fruit are stored in a deep freezer where the temperature is set at -18°C or less.
Processed vegetables and fruit come in cans, jars, and packages. They should be stored on shelves in a cool dry room away from sunlight. It is important to rotate this stock.
Semi-perishable commodities: Semi-perishable commodities are those that do not require refrigeration, but still have a limited shelf life. They include things like potatoes, onions, pumpkins and salamis. These items are usually kept on shelves in the storeroom complex, where they get plenty of air circulation around them. Potatoes need to be kept away from light as they will start sprouting.
Non-perishable commodities
To be real, there is no such thing as non-perishable commodities, as all goods deteriorate overtime. But some commodities deteriorate so slowly that they are called non-perishable. Examples of non-perishable goods are:
- flour
- spices
- canned foods
- jars and bottles
- nuts
- dried packet goods, for example noodles and pasta
These items are usually kept in the dry store where they are kept cool and are protected from moisture contamination. Dry goods like flour, grains and pasta often come in bags or sacks, and are not safe from vermin or weevils and should be transferred to clean storage bins with tightly fitting lids. Some jars, such as caviar, are actually perishable and should be stored appropriately
Food Storage Methods
Reasons For Storage
- To prevent pests from eating and spoiling them.
- To make foodstuffs available always in the house.
- To save cost by bulk buying when food is in season.
- To ensure store is well arranged.
Containers for Storing Food
- Polythene bags and sheets.
- Special wrapping leaves and papers like banana or plantain leaves, foil, etc.
- Plastic containers with tight fitting lids and covered buckets.
- Bottles
- Glass containers
Quiz
- Mention four methods of food preservation.
- What are the reasons for food storage?
- List three containers for storing food.
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