Food Decay and Preservation
Bacteria and fungi are the main groups of decomposer organisms. Food decay is also known as food spoilage.
Bacteria and fungi need Food , Warmth and Moisture to grow.
There are several ways to stop or slow down the decay of foods. This is known as Food Preservation.
Food preservation methods
Freezing
Bacteria cannot reproduce at low temperatures.
Bacteria and fungi need warmth to grow. In low temperatures they stop growing.
Following is the list of food preserved by freezing;
- Meat
- Fish
- Fruits
- Vegetables
- Fresh foods
- Cooked foods
Drying
Removing water prevents the microorganisms from growing, or digesting the food.
Examples:
- Fruit
- milk
- soups,
- pasta
- cereals
- beans
Canning
The sealed can is heated to kill bacteria. When it cools, no more bacteria can enter.
Examples :
- Fruits
- Vegetables
Pickling
Vinegar, used in pickles, is too acidic for bacteria and fungi to be able to grow.
Adding sugar
Removes water by osmosis.
A lot of sugar is added to fruit to make jam, marmalade and jellies.
Adding salt
Salt absorbs water from foods, making the environment too dry to support harmful mold or bacteria.
A lot of salt is added to preserve fish.
