Define methods of Food Preservation?

Food preservation is one of the oldest technologies used by human beings. The perishable food materials like fruits, vegetables, milk, meat, fish and others deteriorate or decay easily, so quite a lot of such commodities are wasted in various stages of food supply chain unless special methods are used for their preservation. Therefore, the process in which, the perishable food materials are given a suitable physical or chemical treatment to prevent their wastage, spoilage and to retain their nutritive value for long periods, is called food preservation. The principles of food preservation refer to the processing techniques that are used to prevent food from spoilage.