Sodium propionate

This white crystalline solid is deliquescent in moist air.

It is used as a food preservative and is represented by the food labeling E number E281 in Europe; it is used primarily as a mold inhibitor in bakery products.

It is approved for use as a food additive in the EU,[2] USA[3] and Australia and New Zealand[4] (where it is listed by its INS number 281).

Anhydrous sodium propionate is a polymeric structure, featuring trigonal prismatic Na+ centers bonded to six oxygen ligands provided by the carboxylates.

With hydrated sodium propionate, some of these Na-carboxylate linkages are displaced by water.

Structure of sodium propionate, with methyl groups and H atoms omitted. [ 5 ] Color code: red = O, blue = Na.