Lactic acid

Lactic acid is identified in the U.S. regulations as 2-hydroxypropanoic acid. It occurs naturally in several foods, and it is also made commercially, either by fermenting sugars such as glucose, sucrose or lactose, or by a chemical process.

The regulation lists its roles in food as an antimicrobial agent, curing and pickling agent, flavor enhancer, pH control agent, and solvent and vehicle. It may be used in food with no limit other than current good manufacturing practice, except in infant foods and infant formulas.

In the baking world, lactic acid is best known for the gentle tang it brings to cultured and fermented foods, and it appears in the ingredient lists of some candies, icings and fillings, where it helps balance sweetness and adjust acidity. Because it is a milder acid than citric acid, it is often chosen for softer, rounder sourness.