L-Malic acid

Description

L-Malic acid is nearly odorless (sometimes a faint, acrid odor) with a tart, acidic taste. It is nonpungent. May be prepared by hydration of maleic acid; by fermentation from sugars.

Description

Malic acid, a hydroxydicarboxylic acid, is found in all forms of life. It exists naturally only as the L-enantiomer. It should not be confused with the similar sounding maleic? and malonic?acids.
L-Malic acid gives many fruits, particularly apples, their characteristic flavor. It is often referred to as “apple acid”. The word malic is derived from the Latin mālum, for which Malus, the genus that contains all apple species, is also named.
The global market size for malic acid (natural and manufactured1) is ≈US$200 million; the US market is ≈$35 million. The primary end use in the United States is for flavoring beverages, foods, and confectionaries, with much smaller quantities used in cosmetics and personal care products. The price of malic acid ranges from US$0.90 to $10.00/kg, depending on the purity, quantity, and end use.
1. The manufactured product is racemic.

Chemical properties

clear colourless solution

Chemical properties

L-Malic acid is nearly odorless (sometimes a faint, acrid odor). This compound has a tart, acidic, nonpungent taste.

Occurrence

Occurs in maple sap, apple, melon, papaya, beer, grape wine, cocoa, sake, kiwifruit and chicory root.

The Uses of L-Malic acid

L-Malic acid is used as a food additive, Selective α-amino protecting reagent for amino acid derivatives. Versatile synthon for the preparation of chiral compounds including κ-opioid receptor agonists, 1α,25-dihydroxyvitamin D3 analogue, and phoslactomycin B.

The Uses of L-Malic acid

The naturally occuring isomer is the L-form which has been found in apples and many other fruits and plants. Selective α-amino protecting reagent for amino acid derivatives. Versatile synthon for the preparation of chiral compounds including κ-opioid rece

The Uses of L-Malic acid

Intermediate in chemical synthesis. Chelating and buffering agent. Flavoring agent, flavor enhancer and acidulant in foods.

Definition

ChEBI: An optically active form of malic acid having (S)-configuration.

Preparation

L-Malic acid can be prepared by hydration of maleic acid; by fermentation from sugar.

General Description

L-Malic acid is an organic acid that is commonly found in wine. It plays an important role in wine microbiological stability.

Biochem/physiol Actions

L-Malic acid is a part of cellular metabolism. Its application is recognized in pharmaceutics. It is useful in the treatment of hepatic malfunctioning, effective against hyper-ammonemia. It is used as a part of amino acid infusion. L-Malic acid also serves as a nanomedicine in the treatment of brain neurological disorders. A TCA (Krebs cycle) intermediate and partner in the malic acid aspartate shuttle.

Purification Methods

Crystallise S-malic acid (charcoal) from ethyl acetate/pet ether (b 55-56o), keeping the temperature below 65o. Or dissolve it by refluxing in fifteen parts of anhydrous diethyl ether, decant, concentrate to one-third volume and crystallise it at 0o, repeatedly to constant melting point. [Beilstein 3 IV 1123.]