Ingredient Information

Function

Propionic acid is mainly used as a preserving agent when added to food. Propionic acid has the ability to inhibit the growth of mold and some bacteria when used in a level from 0.1 to 1 percent by weight, which is why it is a good preservative for human food and cattle feed. Half of the propionic acid produced in the world is destined to be used as an additive for animal feed; when used for this purpose is mainly used as an ammonium salt. Propionic acid is also widely used as an additive to baked goods that tend to grow mold; when used for this purpose is mainly used as a salt of ammonium or calcium.

Other Use and Industries

Propionic acid is used in the animal food industry because, besides its antibiotic and mold controlling properties, it overrules the production of acetic acid in the rumen, therefore producing less carbon dioxide and aiding digestion. Propionic acid is an intermediate in the production of other chemicals, especially polymers like thermoplastics and vinyl.

Propionic acid is also used in pharmaceuticals and pesticides. Esters of propionic acid can be used as solvents and flavoring agents.

Health Effects

Propionic acid used as a food additive should not cause any harm, but extended exposure can irritate the eyes and skin and affect the respiratory function.

Propionic acid is only a concern in patients known to have a genetic disorder known as organic acid disorder or organic acidemia. The main concern in these patients acute acidosis.

Origins

Industrial propionic acid is produces by hydro-carboxylation of ethylene with nickel carboxyl as a catalyst. Propionic acid is also produced by the aerobic oxidation of propionaldehyde by magnesium or cobalt. Propionic acid can also be produced as a byproduct of acetic acid. In nature, propionic acid is produced as its coenzyme, propionyl CoA, from the metabolic breakdown of some fatty acids that contain an odd number of carbon atoms. Also, some bacteria, like propionibacterium, can produce propionic acid. These bacteria can be found in the stomach of ruminants and in the sweat glands of humans.