Disodium EDTA (E386) is the disodium salt of ethylenediaminetetraacetic acid, a polyaminocarboxylic acid that forms stable chelate complexes with metal cations via four carboxylate and two amine groups. Its primary food preservation mechanism is the sequestration of metal ions (particularly iron, copper, manganese) that catalyze lipid oxidation and enzymatic browning, thereby retarding rancidity, color loss, and texture degradation.
An additional antimicrobial effect occurs through chelation of calcium from the outer membrane of Gram-negative bacteria, increasing membrane permeability and synergizing with other preservatives. It is approved as E386 in the EU, FDA 21 CFR 172.135 (calcium disodium EDTA also permitted), and under Codex Alimentarius. JECFA established an ADI of 0–2.5 mg/kg body weight.