Question

4 Explain the following methods of food preservation
(a) Dehydration (b) Canning and Bottling
(c) Pasteurisation​

Answer 1

Answer:

Dehydration :

Dehydration, in food processing, means by which many types of food can be preserved for indefinite periods by extracting the moisture, thereby inhibiting the growth of microorganisms. Dehydration is one of the oldest methods of food preservation and was used by prehistoric peoples in sun-drying seeds.

Canning and Bottling :

Canning or Bottling also known colloquially as putting up or processing, is the process of preserving foods, in particular, fruits, vegetables, and meats, by packing them into glass jars and then heating the jars to create a vacuum seal and kill the organisms that would create spoilage.

pasteurization  :

The process of  pasteurization involves heating milk to 71.7°C for at least 15 seconds (and no more than 25 seconds). Once the milk has been heated, it is then cooled very quickly to less than 3°C. The equipment which is used to heat and cool the milk is called a ‘heat exchanger’.