Calcium Propionate
What it does
Prevents mould in bread.
How it's made
Synthesised propionate salt.
Calcium propionate is the calcium salt of propionic acid and the most common mould inhibitor in bread and baked goods, prized because it stops mould and "rope" bacteria without interfering with the yeast that makes the bread rise. It also adds a little calcium.
It is made by neutralising propionic acid with a calcium base such as calcium hydroxide or calcium carbonate, which converts the pungent acid into an easy-to-handle, near-odourless salt. The product is then purified and dried.
The salt is supplied as a white powder that is simply mixed into the dough. In the finished bread it releases propionic acid slowly, keeping mould at bay for days longer than an untreated loaf; because it does not harm yeast, it is ideal for leavened products, and it is used in small, regulated amounts.
Possible reactions
Reported to worsen behaviour/irritability in some children; occasional migraine.