Sodium fumarate, also called disodium fumarate, is a compound with the molecular formula Na₂C₄H₂O₄. It is the sodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 salt of fumaric acid

Fumaric acid

Fumaric acid or trans-butenedioic acid is the chemical compound with the formula HO2CCH=CHCO2H. This white crystalline compound is one of two isomeric unsaturated dicarboxylic acids, the other being maleic acid. In fumaric acid the carboxylic acid groups are trans and in maleic acid they are cis...

, used as an acidity regulator

Acidity regulator

Acidity regulators, or pH control agents, are food additives added to change or maintain pH . They can be organic or mineral acids, bases, neutralizing agents, or buffering agents....

 in processed foods. Sodium fumarate and fumaric acid are sometimes used as terminal electron acceptors in the cultivation of certain anaerobic microorganisms. It appears as an odourless, white, crystalline powder and is soluble in water.

As a food additive, it has the E number

E number

E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...

E365.