E501: Potassium Carbonate (Potash / Alkaline Noodle Salt)

Direct Answer

E501 (Potassium Carbonates / K2CO3) is an inorganic alkaline mineral salt. INS 501(i), ADI is Not Limited (Quantum Satis), used as the key 'Kansui' alkaline agent in Japanese ramen noodles and in the Dutch processing of cocoa powder.

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

Specs

E-Number Code	E501
INS / Codex Number	INS 501(i) (Potassium Carbonate)
Functional Class	Acidity Regulator, Alkaline Leavening, Kansui Salt
Acceptable Daily Intake (ADI)	Not Limited (Quantum Satis)
Chemical Formula	K2CO3
Primary Mechanism	Alkalinizes noodle dough (pH 9–11), tightening glutenin network and converting flavonoid pigments yellow
Common Target Foods	Ramen noodles (Kansui), Dutch-process alkalized cocoa powder, gingerbread leavening
Dietary Compliance	Vegan (Mineral salt), Halal, Kosher
Safety Approval	EFSA Authorized / FDA GRAS (21 CFR 184.1619)

The Chemistry of Ramen Noodles (Kansui)

Adding E501 potassium carbonate to ramen wheat dough raises pH, causing naturally occurring wheat flavonoid pigments to turn vivid springy yellow while creating the firm, chewy, alkaline tooth-sink (koshi) texture unique to ramen.