1) Food acidity regulator 
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 (E) and in maleic acid they are cis (Z). Fumaric acid has a fruit-like taste...
organic compound related to maleic acid (q.v.).[1 related articles]
Trans-Butanedioic acid;an unsaturated dicarboxylic acid occurring as an intermediate in the tricarboxylic acid cycle. ... Synonym: allomaleic acid. ... (05 Mar 2000) ... 
(fu-mar´ik) an unsaturated dibasic acid, the trans isomer of maleic acid and an intermediate in the tricarboxylic acid cycle.
Type: Term Pronunciation: fū-mar′ik as′id Definitions: 1. an unsaturated dicarboxylic acid occurring as an intermediate in the tricarboxylic acid cycle.
[n] - a colorless crystalline acid with a fruity taste
a colorless, odorless, crystalline, slightly water-soluble solid, CHO, isomeric with maleic acid, essential to cellular respiration in most eukaryotic organisms: used in the making of synthetic resins and as a replacement for tartaric acid in beverages and baking powders. Also called