Làctics

Làctics is a term used in chemistry, biology, and food science to denote lactic acid and its derivatives, including lactates and related esters. The name comes from lactis, the Latin word for milk, reflecting lactic acid’s historical discovery in sour milk.

In chemistry, lactic acid is a chiral alpha-hydroxycarboxylic acid (2-hydroxypropanoic acid) with the formula C3H6O3. It exists as two enantiomers, L- and D-lactic acid; in most organisms, the L form predominates. In solution, it dissociates to lactate and a proton; lactate salts are commonly used as food additives and buffers.

In biology, lactic acid bacteria ferment sugars to lactic acid, a key step in the production of yogurt, cheese, sauerkraut, and sourdough. Bacteria can be homofermentative (primarily lactic acid) or heterofermentative (lactic acid plus other products).

In human physiology, lactate is produced by anaerobic metabolism in muscle during intense exercise. It can be transported to other tissues and used as an energy source; the lactate shuttle concept describes its distribution. Excess lactate can contribute to lactic acidosis in certain medical conditions.

Industrially, lactic acid is produced by fermentation using Lactobacillus species or by chemical synthesis. It is a precursor to polylactic acid (PLA), a biodegradable polymer, and is used as an acidifier, preservative, and humectant in foods, cosmetics, and pharmaceuticals; various lactate salts serve as buffers and electrolytes.

Historically, lactic acid was isolated by Carl Wilhelm Scheele in the 1780s from sour milk, leading to its name.