Malic acid is an organic compound with the formula HO2CCH2CHOHCO2H. It is a dicarboxylic acid that is made from living organisms which contributes to the pleasantly sour taste of fruits and is used as a food additive. Malic acid has two stereoisomeric forms (L- and D-enantiomers), though only the L-isomer exists naturally. The salts and esters of malic acid are known as malates. The malate anion is an intermediate in the citric acid cycle.
Oxidation of Benzene and Butane produces Malic Anhydride which further hydrolyses to give Malic Acid.
Malic acid is added to many food and candies to give a tart taste. Fruity-tasting candies and confections rely on malic acid as a flavoring agent, as do some sodas. Malic acid can be used to preserve or enhance some flavours in processed foods that lose some of their natural flavouring during the processing, like canned fruits.
Malic acid is beneficial in lowering blood pressure. It is also used as a cleansing agent for tooth cavity filling. The malic acid removes food particles in the mouth and leaves a completely clean surface for the dentist to work on, all while being safe to swallow in small amounts. Malic acid is a common ingredient in chemical peels. A chemical peel is applied to the skin to burn away the first layer of dead skin, leaving smooth, fresh skin underneath.
Malic acid is a pH-balancing agent in many cosmetics, rendering these products safer for skin application.