Calcium propionate

Calcium propionate is described in the U.S. regulations as the calcium salt of propionic acid. It appears as white crystals or a crystalline solid and is made by neutralizing propionic acid with calcium hydroxide. Its chemical formula is C6H10CaO4.

The regulation affirms it as generally recognized as safe for use as an antimicrobial agent in food, with no limit other than current good manufacturing practice. The foods it names are baked goods, cheeses, confections and frostings, gelatins, puddings and fillings, and jams and jellies.

Baked goods are listed first, which reflects its common home in the bakery: it is a preservative ingredient that bakers add to bread and cakes so they stay fresh longer on the shelf. Because it is an antimicrobial agent, its job is to hold back the microorganisms that cause spoilage.