E270

E270 is the food additive designation for lactic acid, a weak organic acid used widely in the food industry. It occurs naturally in many fermented foods and in the human body and is produced commercially mainly by fermentation of sugars using lactic acid bacteria, though it can also be prepared synthetically. Lactic acid exists in several isomeric forms, including the L- and D- isomers, and commercial preparations may be racemic (DL-lactic acid).

In foods, E270 serves primarily as an acidity regulator and acidulant, helping to adjust pH and contribute a sour taste. It also acts as a preservative by inhibiting some spoilage organisms. Depending on the product and regulatory framework, lactic acid may be used in liquid and solid foods, and is compatible with a range of processing methods. The additive can be employed in a variety of forms and may be combined with other acidity regulators and stabilizers.

Common applications include dairy products (such as yogurt, sour cream, and cultured dairy beverages), fermented vegetables (like sauerkraut and pickles), meat products, canned fruits and vegetables, beverages, and bakery products. It is also used in cheese production to influence fermentation and texture, and to adjust acidity in many processed foods.

Regulatory status and safety notes vary by jurisdiction. Lactic acid is generally recognized as safe (GRAS) or approved as a standard food additive when used within specified limits. Concentrated solutions are corrosive and can irritate skin and mucous membranes; certain metabolically sensitive individuals may react differently to D-lactic acid in high quantities, though typical dietary use is considered safe.