Explain any two methods of food preservation.

Following are two methods of food preservation:

● Dehydration:

As the name itself suggests dehydration refers to a process of removing water or moisture. Water is an internal factor responsible for the spoilage of food. Removal of water can prevent spoilage of food.

This can be done by drying the food products in the presence of sunlight (as we do with cereals), in the presence of hot air (as we do with potato flakes). All these methods help in vaporizing water and thus prevent the spoilage of food.

● Freezing:

In this, the food is stored at very low temperature i.e. at 0°C. At this temperature, all the metabolic and chemical processes are reduced. Due to this, no bacteria can grow as no metabolic and chemical process can take place. Also, 0°C is not the optimum temperature for the growth of many microorganisms. Thus, the spoiling of food is prevented.