There are many types of preservatives, and different preservatives have different ingredients. The preservative ingredients specified for use are benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, calcium propionate, and 25 others. Here are a few common preservatives.

1, benzoic acid and its salts:

White particles or crystalline powder, odorless or slightly benzoic odor. But the safety is poor, now is not commonly used in food preservation.

2, sorbic acid and its salts:

Sorbic acid, potassium sorbate and calcium sorbate are white crystalline powder or yellowish crystalline powder or scale. Potassium sorbate is easily soluble in water, widely applicable, and can often be seen in some beverages, dried fruit, canned food and other foods.

3, sodium diacetate:

A kind of preservative commonly used in sauces, safe, non-toxic, has a very good preservative effect, the final decomposition product in the body as water and carbon dioxide. It has obvious inhibition effect on black root fungus, Aspergillus flavus and Listeria monocytogenes.

4, sodium lactate:

Colorless or slightly yellow transparent liquid, odorless, slightly salty and bitter, miscible in water, ethanol, glycerol. Sodium lactate is a new type of antiseptic preservative, mainly used in meat and poultry products, meat food bacteria have a strong inhibition effect.

Specifications for the use of preservatives:

Preservatives, not all harmful, in the safe use of the range of human beings is non-toxic side effects.

China's use of preservatives have strict regulations, preservatives should meet the following conditions: rational use of the human body is harmless; does not affect the digestive tract flora; in the digestive tract can be degraded to the normal composition of the food; does not affect the use of pharmaceutical antimicrobials; heat treatment of food does not produce harmful ingredients.

Reference: Baidu Encyclopedia - Preservatives