Potassium Propionate (E283) is produced by neutralizing propionic acid with potassium hydroxide or potassium carbonate. Its antimicrobial activity, like all propionates, derives from the undissociated propionic acid molecule (pKa 4.87) which inhibits fungal and bacterial cell metabolism — specifically interfering with coenzyme A-dependent pathways and inhibiting spore germination and mycelium development.
Potassium Propionate is preferred over calcium propionate in cheese and dairy products where calcium sequestration could affect texture, and over sodium propionate in reduced-sodium formulations. It is approved as E283 in the EU under Regulation 1333/2008, holds FDA GRAS status (21 CFR 184.1828), and is approved by Codex Alimentarius. JECFA assigned an ADI of 'not limited' for propionic acid and all propionates.