Malic acid is an organic compound with the formula HO2CCH2CHOHCO2H. It is a dicarboxylic acid that is made by all living organisms, 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.
Malic acid was first isolated from apple juice by Carl Wilhelm Scheele in 1785. Antoine Lavoisier in 1787 proposed the name acide malique which is derived from the Latin word for apple, mālum. Malic acid contributes to the sourness of green apples. It is present in grapes and in most wines with concentrations sometimes as high as 5 g/l. It confers a tart taste to wine, although the amount decreases with increasing fruit ripeness. The taste of malic acid is very clear and pure in rhubarb, a plant for which it is the primary flavor.
The process of malolactic fermentation converts malic acid to much milder lactic acid. Malic acid occurs naturally in all fruits and many vegetables, and is generated in fruit metabolism.
Malic acid, when added to food products, is denoted by E number E296. Malic acid is the source of extreme tartness in USA-produced confectionery, the so-called extreme candy. It is also used with or in place of the less sour citric acid in sour sweets. These sweets are sometimes labeled with a warning stating that excessive consumption can cause irritation of the mouth. It is approved for use as a food additive in the EU, USA and Australia and New Zealand (where it is listed by its INS number 296).
Malic acid provides 10 kJ/g of energy during digestion.
The pleasant, refreshing experience of biting into a juicy apple or cherry is partly caused by Malic acid.
Malic acid has:
• a clean, mellow, smooth, persistent sourness,
• flavour enhancement and blending abilities,
• a high solubility rate,
• lower hygroscopicity than Citric or Tartaric acids,
• a lower melting point than other acids for easier incorporation into molten confections,
• and good chelating properties with metal ions.
• economical acidulant blends with other acids,
• more soluble calcium salts than Citric acid, and
• effective buffering mixtures.
According to Health Services at Columbia University, malic acid breaks down tooth enamel causing dental decomposition, which is irreversible.
Adding Malic acid improves economies, especially in artificially sweetened products. Flavours are enhanced, allowing less flavour to be used, and the overall flavour profile is broader and more natural.
Malic acid is a preferred acidulant for still beverages (fruit drinks, nectars, iced-teas, sports drinks, calcium fortified juices), because it enhances fruit flavours, improves pH stability, and masks the aftertaste of some salts.
In iced tea, sports drink or fruit soup dry mixes, Malic acid is preferred due to its rapid dissolution rate and flavour enhancement qualities. Since Malic acid provides more sourness than Citric acid, less acidulant is required and unit weight can be reduced.
Low Calorie Beverages
In beverages containing intense sweeteners, less Malic acid than Citric is required to achieve the desired sourness and flavour at a higher pH. Malic acid’s extended sourness masks sweetener aftertaste (see Taste Retention Chart) and its blending and fixative abilities give a balanced taste. In a study with 14-30 year olds, aspartame sweetened low-calorie soft drinks acidified with Malic acid were preferred over those with Citric acid.
To see our Taste Retention Chart please click here.
Ciders and Wines
For „alcoholic” apple ciders, Malic acid is added to maintain a consistent „sharp” taste. In wines, malolactic fermentation improves the flavour profile of the wine.
Acidified „Dairy” Products
• Whey-based protein beverages acidified with Malic acid have enhanced fruit flavour and less noticeable whey flavour.
• Fruit flavoured milk drinks made with fruit juice and acidified with Malic acid have improved flavour and palatability.
• Coagulated soy-milk acidified with Malic acid produces a yoghurt-like product.
Calcium Supplements and Calcium-fortified Beverages
In liquid calcium supplements, Malic acid adds a tart and fruity flavour while controlling the pH. In calcium-fortified beverages, using Malic acid in place of Citric acid prevents turbidity due to precipitated calcium citrate.
Malic acid gives an appealing tartness to hard, soft, tabletted and sugarless candies as well as chewing gum. Blending multiple acids creates unique tasting confections. For example, to prolong the sourness in candy or chewing gum, Citric acid is used for an initial sour boost, Malic acid for a lingering sourness, and Fumaric acid to sustain the tartness even longer. Malic acid’s high solubility allows it be blended with cooled confections. Adding acids at the end of the candy making process minimizes sugar inversion.
Malic acid boosts sourness intensity and enhances fruit flavours. It has a lower melting point than other food acids – this means that it can be incorporated into the molten hard candy without added water – shelf life is increased since the initial moisture level in the hard candy is lower.
In agar, gelatin or pectin-based candies such as jellies and gummies, Malic acid is used to achieve a natural fruit flavour profile, proper gelling and good product clarity.
Malic acid is preferred over Citric acid in this application because it enhances flavour, especially fruit flavours, and boosts sweetness. Blending the sorbitol solution during the heating process is made easier by adding Malic acid.
Organic food acids combined with saccharin improve saliva stimulation in chewing gum. Malic acid is preferred due to its flavour enhancement properties. Using blends of acids with different partition coefficients results in a sequential release of acid – this creates prolonged juiciness and flavour during chewing.
FRUIT PREPARATIONS AND PRESERVES
Malic acid enhances fruit flavours and creates a more natural flavour profile in jams, jellies, and fruit preparations. Malic acid stabilizes pH to control pectin gel texture due to its strong buffering capacity at the pHs used for pectin gels. Fruit preparations are acidified with Malic acid so that the fruit flavour stays strong, even when the fruit preparation is used in dairy products, frozen desserts or baked goods.
• Fruit preparations for frozen desserts show enhanced fruit flavour when Malic acid is included.
• Malic acid is an economical fruit flavour enhancer in sherbets and water ices.
• In gelled desserts, Malic acid enhances fruit flavours and helps stabilize pH to control gel texture.
Bakery products with fruit fillings (cookies, snack bars, pies, and cakes) have a stronger and more naturally balanced fruit flavour when the fruit filling includes Malic acid. Pectin gel texture is more consistent due to Malic acid’s buffering capacity.
MEDICAL AND PERSONAL CARE PRODUCTS
In throat lozenges, cough syrups, and effervescent powdered preparations, Malic acid enhances fruit flavour and can diminish the flavour impact of active components. As Malic acid stimulates saliva flow, it can be used in tooth-cleaning preparations and mouthwashes. Germicidal compounds are used in combination with Malic acid in soaps, mouthwashes, and toothpaste.
Acid-Based Facial Products
Malic acid, an alpha hydroxy fruit acid, can be used in skin care products to rejuvenate and improve skin conditions.