The agricultural products of low moisture contents such as corn and soybeans when exposed to higher humidity take up enough moisture contents to permit the growth of moulds and bacteria.
(ii) Microbial activities:
There are several kinds of food which tend to spoil by microbial attack. Fish, poultry and dairy products are specifically spoiled by microbial growth.
FOOD PRESERVATION METHODS:
There are numerous methods of preservation of foods. Some of the most widely used ones are described here.
(i) Removal of moisture:
This method of preservation of food relates to the removal of water or drying process. The products that need to be dried are the various pastes, milk, coffee and tea, some vegetable, fruits, meat and eggs.
Dried foods are easy to store or transport because they occupy only about one-tenth the volume of fresh food. The use of this technique controls the growth of microorganisms, which render the food to spoil.
(ii) Addition of salt and sugar:
As a means of chemical preservation, sugar and salt are added to many sausages to increase their shelf life. The sugar and salt bind the water, which helps the microorganisms to grow. The inhibition in growth of microbes by this way retards the process of food spoilage. The water-binding agents are known as humectants.