E330: Citric Acid (Universal Acidulant / Chelator)

Direct Answer

E330 (Citric Acid) is a tricarboxylic organic acid produced by industrial fermentation of Aspergillus niger on carbohydrate substrates. INS 330, ADI is Not Limited (Quantum Satis), the single most widely used acidulant, flavor enhancer, and metal chelator on Earth.

Source: Codex Alimentarius / EFSA · Last reviewed Aug 28, 2026

Specs

E-Number Code	E330
INS / Codex Number	INS 330
Functional Class	Acidity Regulator, Acidulant, Sequestrant, Antioxidant Synergist
Acceptable Daily Intake (ADI)	Not Limited (Quantum Satis)
Chemical Formula	C6H8O7 (2-hydroxypropane-1,2,3-tricarboxylic acid)
Primary Mechanism	Delivers bright citrus sourness; chelates pro-oxidant metal ions (Fe/Cu); activates pectin gelation
Common Target Foods	Citrus beverages, candy/confectionery, jams, canned tomatoes, cheese curdling, soft drinks
Dietary Compliance	100% Vegan (Aspergillus fungal sugar fermentation), Halal, Kosher
Safety Approval	EFSA Authorized / FDA GRAS (21 CFR 184.1033)

Metal Chelation & Antioxidant Synergy

Citric acid's three carboxyl groups bind trace pro-oxidant iron (Fe3+) and copper (Cu2+) into inert multidentate chelates, preventing Fenton reactions and multiplying the shelf-life efficacy of ascorbic acid and polyphenols.