E509: Calcium Chloride (Firming Agent / Cheese Salt)

Direct Answer

E509 (Calcium Chloride / CaCl2) is an inorganic calcium mineral salt. INS 509, ADI is Not Limited (Quantum Satis), serving as a crucial firming agent in canned tomatoes, tofu coagulant, and rennet coagulation restorer in pasteurized milk cheese making.

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

Specs

E-Number Code	E509
INS / Codex Number	INS 509
Functional Class	Firming Agent, Coagulant, Sequestrant, Electrolyte
Acceptable Daily Intake (ADI)	Not Limited (Quantum Satis)
Chemical Formula	CaCl2
Primary Mechanism	Divalent Ca2+ ions cross-link pectin galacturonan chains in plant cell walls and bridge casein micelles in milk
Common Target Foods	Canned whole peeled tomatoes (prevents mushiness), pasteurized cheese vats, soy tofu coagulation, sports pickles
Dietary Compliance	Vegan (Natural brine/limestone salt), Halal, Kosher
Safety Approval	EFSA Authorized / FDA GRAS (21 CFR 184.1193)

Pectin Cross-Linking in Canned Tomatoes

Adding E509 calcium chloride to canned tomatoes allows Ca2+ ions to bind free carboxyl groups of native tomato pectin, creating an insoluble calcium pectate gel that prevents thermal canning from turning tomatoes into mush.