Lactic Acid
Common Additive Used As A Preservative And An Acidifier
About Lactic Acid
Lactic acid exists either as a white solid in pure form, or a clear to yellowish liquid when dissolved in water. It can be produced via fermentation of carbohydrates, or synthesized from acetaldehyde. It is a chiral molecule, which means it exists in D- or L- form, or as a racemic mixture. Any of the three forms may occur in nature depending upon the biological pathway. The L-enantiomer of lactic acid is produced from the breakdown of pyruvate during normal cell metabolism, and may build up during intense exercise when the production rate exceeds the processing rate.
Lactic acid is responsible for the tangy flavor of fermented milk products (e.g. yogurt, kefir), sour beers, and sourdough bread. Fermentation usually results in the racemate, although some fermenting bacteria produce the D-enantiomer only. In winemaking, some wines may go through a natural or induced process called malolactic fermentation, which converts malic acid to lactic acid, to reduce the sharpness of the acidity. Given its prevalence in nature, lactic acid is useful for manipulating food chemistry, and is therefore a common additive. It may be used as a preservative, an acidifier, a dairy culturing agent, or an ingredient in infant formulas. It may also be used in pharmaceuticals and cosmetics as a preservative and acidifier, and in contraceptive jellies as an active ingredient.
Common Uses and Applications
- Preservative
- Dairy culturing agent
- Contraceptive jellies
- Acidifier
- Pharmaceutical ingredient
- Cosmetic ingredient