E330 Antioxidant

E330 is the organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. Usually encountered as a white solid, it is a weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the E330  cycle, which occurs in the metabolism of all aerobic organisms.

More than two million tons of E330 are manufactured every year. It is used widely as an acidifier, as a flavoring, and a chelating agent.

A citrate is a derivative of E330; that is, the salts, esters, and the polyatomic anion found in the solution. An example of the former, a salt is trisodium citrate; an ester is triethyl citrate. When part of a salt, the formula of the citrate anion is written as