Question

Write a note on food preservatives.

Answer 1

Food can be preserved by adding natural and synthetic preservatives.
A. Natural preservatives:
Some naturally available materials like salt, sugar, and oil are used as food preservatives.

1. Addition of salt: It is one of the oldest methods of preserving food. The addition of salt removes the moisture content in the food by the process of osmosis. This prevents the growth of bacteria and reduces the activity of microbial enzymes. Meat, fish, gooseberry, lemon, and raw mangoes are preserved by salting. Salt is also used as a preservative in pickles, canned foods, etc.
2. Addition of sugar: Sugar/Honey is added as a preservative to increase the shelf life of fruits and fruit products like jams, jellies, squash, etc. The hygroscopic nature of sugar/honey helps in reducing the water content of food and also minimizing the process of oxidation in fruits.
3. Addition of oil: The addition of oil in pickles prevents the contact of air with food. Hence microorganisms cannot grow and spoil the food.

B. Synthetic preservatives:

Synthetic food preservatives like sodium benzoate, citric acid, vinegar, sodium meta bisulfate, and potassium bisulfate are added to food products like sauces, jams, jellies, packed foods, and ready-to-eat foods. These preservatives delay microbial growth and keep the food safe for a long duration.