Sodium fumarates

Sodium fumarates are the sodium salts of fumaric acid, a dicarboxylic acid that occurs naturally as an intermediate in the Krebs (citric acid) cycle — the central pathway of cellular energy metabolism in all aerobic organisms. As food additives, sodium fumarates function as acidity regulators and acidulants, contributing a clean, dry acidic note to beverages, baked goods, and confectionery. They are also used as leavening acid components in baking powder formulations, where they react with sodium bicarbonate to release carbon dioxide and cause dough to rise.

JECFA evaluated the fumarate family in 1969 and established a group ADI of 6 mg/kg body weight per day expressed as fumaric acid for sodium, potassium, and calcium fumarates collectively. This group ADI reflects the shared metabolism of all fumarate salts: in the body, fumarate enters the Krebs cycle directly and is completely oxidised to carbon dioxide and water, making it among the most metabolically clean of the food acidulants. No accumulation or specific toxicological concern exists at intake levels consistent with food use.

Sodium fumarates are approved in the EU and internationally for use as acidity regulators in a range of food categories. Fumaric acid and its salts are valued as particularly efficient leavening acids due to their controlled reaction rate: they begin to react more slowly with bicarbonate at room temperature but react rapidly in the oven, providing better oven spring. On ingredient labels they appear as sodium fumarate(s) or E365. They are encountered less frequently than citric acid or tartaric acid in retail products but fill a specific niche in commercial baking and beverage acidification applications.