Explain any two chemical methods of food preservation.

Explanation

Chemical methods : Chemically presevation can be done by adding sugar, salt or vinegar in food Chemicals like sodium benoate, salts or sorbic acid and propionic acid etc. are used as preservatives.
(a) Preservation by addition of sugar and then applying heat is highly important method in case of fruits to prepare jams, jellies and marmalades, This method is simple, cheap and easy to adopt.
(b) Salting is also used to control the growth of fungus or micro-organisums in food storing. It is mainly used in preparation of pickles of raw mango, lemon, chillies, etc., and to preserve fish products. The anti-microbial activity of common salt is due to osmosis, a cell loses water, dies or remains dormant. It is an oldest method to preserve food.