E338: Phosphoric Acid (Cola Acidulant)

Direct Answer

E338 (Phosphoric Acid / H3PO4) is a mineral inorganic acid providing a uniquely dry, tangy, astringent sourness. INS 338, group ADI is 40 mg/kg bw/day (as phosphorus), the quintessential acidulant in cola beverages and processed cheeses.

Source: EFSA FAF Panel (2019) / FDA · Last reviewed Aug 28, 2026

Specs

E-Number Code	E338
INS / Codex Number	INS 338
Functional Class	Acidulant, Acidity Regulator, Sequestrant, Emulsifying Salt
Acceptable Daily Intake (ADI)	40 mg / kg body weight per day (Group ADI as phosphorus)
Chemical Formula	H3PO4 (pKa1 2.15)
Primary Mechanism	Lowers beverage pH to ~2.5 with a clean, sharp, non-fruity tang; retards bacterial outgrowth
Common Target Foods	Cola soft drinks, root beers, processed cheese melts, sports hydration drinks
Dietary Compliance	Vegan (Mineral phosphate synthesis), Halal, Kosher
Safety Approval	EFSA Authorized / FDA GRAS (21 CFR 182.1073)

The Non-Fruity Clean Tang of Colas

Unlike organic citric or malic acids which give fruity apple/lemon flavor undertones, phosphoric acid imparts a pure, sharp, mineral sourness that cuts through heavy sugar sweetness without interfering with spicy cola aromatics.