malico

Malico is a term used in several Romance languages to refer to malic, particularly malic acid and substances derived from it. In scientific contexts, malico commonly denotes the malic acid molecule itself, as well as salts, esters, and other derivatives of malic acid. The name derives from Latin malum, meaning apple, reflecting the high concentration of malic acid found in apples and many fruits.

Chemistry and properties: Malic acid is a dicarboxylic acid with the formula C4H6O5. It is an alpha-hydroxy dicarboxylic acid, featuring two carboxyl groups and one hydroxyl group. Naturally occurring malic acid is mainly in the L-form (L-malic acid), which is chiral. It has two dissociable protons with approximate pKa values around 3.4 and 5.1, making it a moderately strong organic acid. It is highly soluble in water and forms various salts and esters used in different applications. In food chemistry, malic acid acts as an acidulant and flavor enhancer.

Occurrence and uses: Malic acid occurs widely in fruits, particularly apples, grapes, and cherries. It is used as a food additive (often labeled as E296) to provide tartness and to adjust acidity in beverages, candies, and processed foods. In winemaking, malic acid influences taste and mouthfeel, and malolactic fermentation converts malate to lactic acid, softening acidity. Malic derivatives are used in cosmetics and some pharmaceutical formulations.

Biological role: In metabolism, malate is an intermediate of the citric acid cycle. Malate participates in gluconeogenesis and redox reactions, and malate dehydrogenase catalyzes the reversible conversion between malate and oxaloacetate.

History: The compound was first identified from apples in the late 18th century. Its name reflects its association with apples, a prominent natural source.