As a food additive, citric acid has the functions of regulating sour taste and keeping fresh, and is also used as detergent in washing industry. It can be extracted from plant raw materials or made from sugar by citric acid fermentation. It can be used to make medicine, soda, candy, metal cleaner, mordant and so on. It is an important part of the tricarboxylic acid cycle.

Citric acid is a sour agent, which is mainly used in food, medicine and chemical industry. In the process of food use, different amounts of citric acid are added according to different formulas, and the addition process is generally in the feeding stage of food main raw materials.