As a food Preservatives, it is listed as E number 282 in the Codex Alimentarius. Calcium Propionate is used as a preservative in a wide variety of products, including but not limited to bread, other baked goods, processed meat, whey, and other dairy products. In agriculture, it is used, amongst other things, to prevent milk fever in cows and as a feed supplement Propionates prevent microbes from producing the energy they need, like benzoates do. However, unlike benzoates, propionates do not require an acidic environment.

Calcium propionate is used in bakery products as a mold inhibitor, typically at 0.1-0.4% (though animal feed may contain up to 1%). Mold contamination is considered a serious problem amongst bakers, and conditions commonly found in baking present near-optimal conditions for mold growth. Calcium propionate (along with propionic acid andSodium Propionate) is used as a preservative in bread and other baked goods. It also occurs naturally in butter and some types of cheese. Calcium propionate keeps bread and baked goods from spoiling by preventing mold and bacterial growth. Although you may be concerned about the idea of preservative use in food, on the flip-side, you certainly don want to eat bacteria- or mold-infested bread.