Calcium Propionate Calcium propionate is manufactured by reacting propionic acid with calcium hydroxide, used as an antimicrobial preservative, mold inhibitor, and dough conditioner (INS 282) that inhibits mold/yeast/bacterial growth through propionate ion disruption of microbial metabolism while providing calcium nutrition and buffering. In the food industry, food-grade forms excel at extending shelf life in yeast-leavened bakery without affecting fermentation or taste.