First described by Johann Gottlieb in 1844, propanoic acid, also known as propionic acid, has become one of the additives widely used in processed foods for human consumption and animal feed.
Propionic acid is used primarily as a preservative in food and as a preservative in feed and corn for animal feed. Similarly, due to its antimicrobial properties, it has been studied as a possible alternative to growth-promoting antibiotics, but without good results. Propionic acid is also used as a chemical intermediary, mainly in the synthesis of polymers.
It is a short chain fatty acid – AGCC or Ác. Volatile Grease – AGV that presents itself in the natural state, as one of the products of cellulose digestion by bacteria that reside in the rumen of herbivorous animals. The fermentation of the plant material ingested in the rumen is an anaerobic process that converts cellulosic carbohydrates into short-chain fatty acids (acetic acid, propionic and butyric acid, mainly).
The activity depends on the pH in the substance to be preserved, with the uncoupled form being the most active (11 to 45 times more than the dissociated form). They have identical efficacy against microorganisms and are quite effective against molds, but have little action against most bacteria and have no effect against yeasts, in the amounts recommended for use in food.
Propionates are widely used in the bakery industry due to their low performance against biological yeasts. Typically, calcium propionate is used in salty products and sodium propionate in sweet products. They do not show any acute or sub-chronic toxicity, but were temporarily banned in Germany and Austria as food preservatives, before being readmitted under the European Directives. The recommended propionic acid dosage is not fixed. There is no limit to the concentration of these products and you must therefore obey the GMP’s; concentrations are usually less than 0.4%.