Citric Acid is mainly used as acidulant, flavouring agent, preservative and antistaling agent in food and beverage industry. Moreover, it is also used as antioxidant, plasticizer and detergent in chemical, cosmetics and cleaning industries. In the food industry, it is used as the acidulant in the making of soda, candy, biscuit, can, jam, juice and so on.

In the medicine industry, it is the raw material of many pharmaceuticals, such as ferric ammonium citrate (blood tonic), sodium citrate (blood transfusion agent) and so on. Moreover, citric acid is also used as the acidulant in lots of medicines. In the chemical industry, esters of citric acid can be taken as the non-toxic plasticizer to make the plastic film of food package.  

It can be used as both the auxiliary agent in the industrial and civil detergent to make nuisanceless detergent and the retarder in concrete. Moreover, it is also applied to industries like electroplating, leather and ink.  

At room temperature, citric acid is a white crystalline powder. It can exist either in an anhydrous (water-free) form or as a monohydrate. The anhydrous form crystallizes from hot water, whereas the monohydrate forms when citric acid is crystallized from cold water. The monohydrate can be converted to the anhydrous form by heating it above 74 c. Citric acid also dissolves in absolute (anhydrous) ethanol (76 parts of citric acid per 100 parts of ethanol) at 15 degrees celsius. In chemical structure, citric acid shares the properties of other carboxylic acids. When heated above 175 c, it decomposes through the loss of carbon dioxide and water.