CAS NUMBER: 97-67-6
EC NUMBER: 202-601-5
MOLECULAR FORMULA: HO2CCH2CH(OH)CO2H
MOLECULAR WEIGHT: 134.09
L-Malic acid is the naturally occurring isomer of malic acid, found mainly in sour and unripe fruits.
L-Malic acid acid is an organic acid that is commonly found in wine. It plays an important role in wine microbiological stability.
L-Malic acid acid is a selective α-amino protecting reagent for amino acid derivatives.
L-Malic acid is also a versatile synthon for the preparation of chiral compounds including κ-opioid receptor agonists, 1α,25-dihydroxyvitamin D3 analogue, and phoslactomycin B.
L-Malic acid is an organic compound with the molecular formula C4H6O5.
L-Malic acid is a dicarboxylic acid that is made by all living organisms, contributes to the sour taste of fruits, and is used as a food additive.
L-Malic acid has two stereoisomeric forms, though only the L-isomer exists naturally.
The salts and esters of malic acid are known as malates.
L-Malic acid anion is an intermediate in the citric acid cycle.
L-Malic acid plays an important role in biochemistry.
In the C4 carbon fixation process, malate is a source of CO2 in the Calvin cycle.
In the citric acid cycle, (S)-malate is an intermediate, formed by the addition of an -OH group on the si face of fumarate.
It can also be formed from pyruvate via anaplerotic reactions.
L-Malic acid is nearly odorless (sometimes a faint, acrid odor) with a tart, acidic taste.
L-Malic acid is nonpungent. May be prepared by hydration of maleic acid; by fermentation from sugars.
L-Malic acid is also synthesized by the carboxylation of phosphoenolpyruvate in the guard cells of plant leaves.
L-Malic acid, as a double anion, often accompanies potassium cations during the uptake of solutes into the guard cells in order to maintain electrical balance in the cell.
The accumulation of these solutes within the guard cell decreases the solute potential, allowing water to enter the cell and promote aperture of the stomata.
L-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—as is its genus name Malus.
In German it is named Äpfelsäure (or Apfelsäure) after plural or singular of the fruit apple, but the salt(s) Malat(e).
L-Malic acid is the main acid in many fruits, including apricots, blackberries, blueberries, cherries, grapes, mirabelles, peaches, pears, plums, and quince and is present in lower concentrations in other fruits, such as citrus.
L-Malic acid contributes to the sourness of unripe apples. Sour apples contain high proportions of the acid.
L-Malic acid is present in grapes and in most wines with concentrations sometimes as high as 5 g/l.
L-Malic acid confers a tart taste to wine; 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.
L-Malic acid is also a component of some artificial vinegar flavors, such as "salt and vinegar" flavored potato chips.
In citrus, fruits produced in organic farming contain higher levels of malic acid than fruits produced in conventional agriculture.
The process of malolactic fermentation converts malic acid to much milder lactic acid.
L-Malic acid occurs naturally in all fruits and many vegetables, and is generated in fruit metabolism.
L-Malic acid, when added to food products, is denoted by E number E296.
L-Malic acid is sometimes 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.
L-Malic acid is approved for use as a food additive in the EU, US and Australia and New Zealand.
L-Malic acid is a 2-hydroxydicarboxylic acid that is succinic acid in which one of the hydrogens attached to a carbon is replaced by a hydroxy group.
L-Malic acid has a role as a food acidity regulator and a fundamental metabolite.
L-Malic acid is a 2-hydroxydicarboxylic acid and a C4-dicarboxylic acid.
L-Malic acid derives from a succinic acid.
L-Malic acid is a conjugate acid of a malate(2-) and a malate.
L-Malic acid, a hydroxydicarboxylic acid, is found in all forms of life.
L-Malic acid exists naturally only as the L-enantiomer.
L-Malic acid should not be confused with the similar sounding maleic and malonic acids.
L-Malic acid, like citric acid, is a general purpose acidifier.
The name malic acid is normally associated with apples.
In fact, the common name malik derives from the Latin word mala, although it has an important acid component such as cranberry, grape, guava, blueberry, papaya, passionfruit, peach, pear, pineapple, plum, and raspberry.
Although malic acid is used in many food products, it is often preferred in apple-containing foods such as cider due to its aroma and relatively higher cost than citric acid.
L-Malic acid, however, has a fuller and smoother flavor than citric acid, which is useful in low-energy drinks where malic acid masks the unpleasant taste of some artificial sweeteners.
L-Malic acid is economically positioned between citric and tartartic acids in price.
L-Malic acid gives many fruits, particularly apples, their characteristic flavor.
L-Malic acid 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 L-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.
L-Malic acid is a tart-tasting organic dicarboxylic acid that plays a role in many sour or tart foods.
Apples contain malic acid, which contributes to the sourness of a green apple. Malic acid can make a wine taste tart, although the amount decreases with increasing fruit ripeness.
In its ionized form malic acid is called malate. Malate is an intermediate of the TCA cycle along with fumarate.
L-Malic acid can also be formed from pyruvate as one of the anaplerotic reactions.
In humans, malic acid is both derived from food sources and synthesized in the body through the citric acid cycle or Krebs cycle which takes place in the mitochondria. Malate's importance to the production of energy in the body during both aerobic and anaerobic conditions is well established.
Under aerobic conditions, the oxidation of malate to oxaloacetate provides reducing equivalents to the mitochondria through the malate-aspartate redox shuttle.
During anaerobic conditions, where a buildup of excess of reducing equivalents inhibits glycolysis, malic acid's simultaneous reduction to succinate and oxidation to oxaloacetate is capable of removing the accumulating reducing equivalents.
This allows malic acid to reverse hypoxia's inhibition of glycolysis and energy production.
In studies on rats it has been found that only tissue malate is depleted following exhaustive physical activity.
Other key metabolites from the citric acid cycle needed for energy production were found to be unchanged.
Because of this, a deficiency of malic acid has been hypothesized to be a major cause of physical exhaustion.
Notably, the administration of malic acid to rats has been shown to elevate mitochondrial malate and increase mitochondrial respiration and energy production.
L-Malic acid is a chemical found in certain fruits and wines. It is used to make medicine.
L-Malic acid (E 296) is preferred in the beverage industry due to its compatibility with aroma substances, its long-lasting taste on the palate and its easy dissolution feature.
L-Malic acid is used in leavening products and concentrated beverages due to its ability to extend the shelf life of food products.
L-Malic acid is also used in canned food as it provides pH control in food products.
L-Malic acid is used in the production of dairy products and beer, as it reduces the formation of sediment.
L-Malic acid is used in the production of hard candy with its ability to increase brightness and clarity.
L-Malic acid (E296) It is used for cleaning metal surfaces except food.
L-Malic acid (Malic Acid) salts are a general purpose acidity regulator.
L-Malic acid is used in the food industry to create and accentuate the natural flavor effect.
An application has been filed to include the use of malic acid in organic food processing operations.
Synthetic DL malic acid is used as a pH adjuster in food processing operations.
L-Malic acid is a food processing aid used in bottled iced teas, dry mix drinks, sodas, baked goods, juices, confectionery, gelatins, desserts, frozen specialties and sports drinks.
Non-food uses of malic acid include pharmaceuticals, paints, metal cleaning, electroplating, soaps.
The NOP final rule does not list malic acid as an approved substance allowed in the processing of "organic" products under sections 205.605 or 205.606.
However, the rule lists citric acid as an approved processing aid in section 205.605 if citric acid is produced by microbial fermentation of carbohydrate substances (non-synthetic).
L-Malic acid standards state that malic acid should not be used solely as a flavor, color, or texture enhancer or preservative.
L-Malic acid is in demand for use as a pH adjuster.
L-Malic acid is also used in beverage dry mixes, sodas, baked goods, juices, candies, gelatins, desserts, frozen specialties, and other foods.
L-Malic acid is often used in the production of low-calorie beverages.
L-Malic acid is slightly less expensive than citric acid and can replace citric acid in some flavored CBs.
L-Malic acid enhances fruit flavors in soft drinks by prolonging their release and thus receptor cells are stimulated for a longer period of time, which is translated by the brain as a stronger fruit flavor.
L-Malic acid provides more acidity per weight unit than other acidifiers used in carbonated soft drinks.
The result is a reduced weight of pre-weighed acidifier packs.
L-Malic acid can also save cost, and if used, it is recommended to be dissolved in beverage syrup (0.03% - 0.90%) after the addition of benzoates is completely dissolved.
Despite L-Malic acids ominous-sounding name, the word malic acid comes from the Latin word malum, meaning apple.
L-Malic acid was first isolated from apple juice in 1785, and it is what gives some foods and beverages a sour taste.
If you're a fan of slightly acidic wines, malic acid probably played a big part.
L-Malic acid, also known as "apple acid" and "fruit acid", is an organic compound and is found in many prepared foods.
L-Malic acid is found naturally in apples, especially its skin and other fruits.
L-Malic acid is the so-called alpha-hydroxy organic acid and is also found in many plant and animal species.
This intermediate is the key element in the Krebs cycle (also known as the citric acid cycle), the main cellular energy production cycle.
L-Malic acid is usually found on the food label, but it is not dangerous or toxic to human health.
L-Malic acids purpose is to increase the acidity of food, to give it more flavor, but it is also used as a flavoring agent and color stabilizer.
L-Malic acid is identified by the abbreviation E296.
This acidifying compound is widely used in the food industry and is usually obtained through a chemical synthesis.
L-Malic acid is normally found in fruit juices (mostly grapes or apples), but also in jellies, fruit spreads, jams, wine and some low-calorie foods.
Malic acid is found in nature in small amounts in foods such as prunes, currants, tomatoes, and even bananas.
This fruit acid is closely related to acid and is characterized by a sour, bitter, strong and penetrating taste.
L-Malic acid is used as a flavor enhancer and food acidifier.
People take malic acid by mouth for tiredness and fibromyalgia.
In foods, malic acid is used as a flavoring agent to give food a tart taste.
In manufacturing, malic acid is used to adjust the acidity of cosmetics.
L-Malic acid is a commodity chemical that was first isolated in the crystalline form in the 18th century, yet it has been troublesome for more than 100 years because of its resistance to forming crystals that are suitable for optical or X-ray analysis.
L-Malic acid crystallizations from the melt and from solutions are reevaluated here. Indeed, LMA crystallizes poorly from water.
L-Malic acid is a substance found naturally in apples and pears. It's considered an alpha-hydroxy acid, a class of natural acids commonly used in skin-care products.
Also sold in dietary supplement form, malic acid is said to offer a variety of benefits.
L-Malic acid is found naturally in fruits including apricots, blackberries, blueberries, cherries, grapes, peaches, pears, and plums.
L-Malic acid is also found in some citrus fruits.
In food, malic acid may be used to acidify or flavor foods or prevent food discoloration. It may also be used with other ingredients in cosmetics.
Using malic acid as part of your skin care routine may help with concerns such as pigmentation, acne, or skin aging. But keep in mind that it's a good idea to patch test when using new products and to avoid the eye area.
If you choose to take a malic acid supplement, the National Institutes of Health (NIH) offers tips to consumers. The organization recommends that you look for a Supplement Facts label on the product. This label will contain vital information including the amount of active ingredients per serving, and other added ingredients.
Lastly, the organization suggests that you look for a product that contains a seal of approval from a third party organization that provides quality testing. These organizations include U.S. Pharmacopeia, ConsumerLab.com, and NSF International. A seal of approval from one of these organizations does not guarantee the product's safety or effectiveness but it does provide assurance that the product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants.
USES:
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.
White or nearly white, crystalline powder or granules having a slight odor and a strongly acidic taste.
L-Malic acid is hygroscopic. The synthetic material produced commercially in Europe and the USA is a racemic mixture, whereas the naturally occurring material found in apples and many other fruits and plants is levorotatory.
L-Malic acid is the third smallest alpha hydroxy acid in terms of molecular size.
Although it is used in numerous cosmetic products, particularly those indicating a “fruit acid” content and generally designed for anti-aging, unlike glycolic and lactic acids, its skin benefits have not been extensively studied.
Some formulators consider it difficult to work with, particularly when compared to other AHAs, and it can be somewhat irritating.
L-Malic acid is rarely used as the only AHA in a product. It is found naturally occurring in apples.
L-Malic acid is an acidulant that is the predominant acid in apples.
L-Malic acid exists as white crystalline powder or granules and is considered hygroscopic.
As compared to citric acid, it is slightly less soluble but is still readily soluble in water with a solubility of 132 g/100 ml at 20°c.
L-Malic acid has a stronger apparent acid taste and has a longer taste retention than citric acid which peaks faster but does not mask the aftertaste as effectively.
A quantity of 0.362–0.408 kg of malic acid is equivalent to 0.453 kg of citric acid and to 0.272–0.317 kg of fumaric acid in tartness.
At temperatures above 150°c it begins to lose water very slowly to yield fumaric acid.
L-Malic acid is used in soft drinks, dry-mix beverages, puddings, jellies, and fruit filling.
L-Malic acid is used in hard can- dies because L-Malic acid has a lower melting point (129°c) than citric acid which improves the ease of incorporation.
APPLICATION:
When L-Malic acid is used to enhance flavor in the food industry, fewer flavor additives are generally needed.
This improves economies while the overall flavor profile is wider and more natural.
In soft drinks, malic acid is a preferred acidifier as it can enhance fruit flavors and mask the aftertaste of some salts.
L-Malic acid is preferred in powdered mixtures because of its fast dissolution rate.
In beverages containing intense sweeteners, the long-lasting sourness of malic acid masks the sweetener afterward, and its blending and fixing abilities provide a balanced flavor.
Using malic acid instead of citric acid in calcium-fortified beverages prevents cloudiness caused by precipitation of calcium citrate.
L-Malic acid has a lower melting point than other food acids - meaning it can be added to melted hard candy without added water increasing shelf life because the initial moisture level in hard candy is lower.
Fruit-filled baked goods (cookies, snacks, pies, and cakes) have a stronger and more naturally balanced fruit flavor when the fruit filling contains malic acid.
The pectin gel texture is more consistent due to the buffering capacity of Malic Acid.
L-Malic acid is the predominant active component of prune juice concentrate as a natural mold inhibitor in the cooking of products.
L-Malic acid may be used to prepare:
-diethyl (S)-malate
-ethyl (R)-2-hydroxyl-4-phenylbutanoate
-ethyl (S)-2-hydroxyl-4-phenylbutanoate
-D-homophenylalanine ethyl ester hydrochloride
-furo[3,2-i]indolizines
PHARMACEUTICAL APPLICATION:
L-Malic acid is used in pharmaceutical formulations as a generalpurpose acidulant.
L-Malic acid possesses a slight apple flavor and is used as a flavoring agent to mask bitter tastes and provide tartness.
L-Malic acid is also used as an alternative to citric acid in effervescent powders, mouthwashes, and tooth-cleaning tablets.
In addition, L-Malic acid has chelating and antioxidant properties.
L-Malic acid may be used with butylated hydroxytoluene as a synergist in order to retard oxidation in vegetable oils.
In food products it may be used in concentrations up to 420 ppm.
Therapeutically, L-Malic acid has been used topically in combination with benzoic acid and salicylic acid to treat burns, ulcers, and wounds.
L-Malic acid has also been used orally and parenterally, either intravenously or intramuscularly, in the treatment of liver disorders, and as a sialagogue.
BENEFITS:
L-Malic acid is found in fruits and vegetables and is produced naturally in the body when carbohydrates are converted into energy.
While some research suggests that L-Malic acid supplements may help people with certain conditions, high-quality clinical trials are needed.
When applied to the skin, malic acid is said to reduce signs of aging, remove dead skin cells, aid in the treatment of acne, and promote skin hydration.
A number of early studies published in the 1990s and early 2000s indicate that malic acid may be beneficial when applied to the skin.
In tests on animals and human cells, the studies' authors found that malic acid may help increase collagen production and reverse sun-induced signs of skin aging.
More recent research on topically applied malic acid includes a small study published in the Journal of Drugs in Dermatology in 2013.
For the study, researchers assigned people with melasma (a common disorder marked by patches of abnormally dark skin) to a skin-care regimen that included the use of topical vitamin C and malic acid.
At an average follow-up of 26 months, the regimen was found to be an effective short-term treatment for melasma.
L-Malic acid is also used to boost sports performance when taken in supplement form.
L-Malic acid is sometimes combined with creatine supplements in order to improve the body's absorption of creatine.
Proponents claim that malic acid can promote energy production, increase exercise endurance, and help fight off muscle fatigue.
For a study published in Acta Physiologica Hungarica in 2015, researchers investigated the effectiveness of a creatine-malate supplement in sprinters and long-distance runners.
After six weeks of supplementation combined with physical training, there was a significant increase in the physical performance in sprinters, measured by peak power, total work, body composition, and elevated growth hormone levels.
In long-distance runners, there was a significant increase in distance covered.
L-Malic acid is a precursor to citrate, a substance believed to prevent calcium from binding with other substances in urine that form kidney stones.
Citrate may also prevent crystals from getting bigger by preventing them from sticking together.
According to a preliminary laboratory study published in 2014, malic acid consumption may increase urine pH and citrate levels, making stone formation less likely.
The study authors concluded that malic acid supplementation may be useful for the conservative treatment of calcium kidney stones.3
In a 2016 review, scientists suggested that given the high malic acid content in pears, future research should explore whether a diet supplemented with pears and low in meat and sodium may reduce stone formation.
In addition to the food industry, L-Malic acid is used very often in cosmetics.
In fact, there are numerous beauty creams, scrubs, and facial and body-specific products containing more or less percentages of this substance.
The reason behind the widespread use of the so-called apple acid is closely related to its biochemical function.
L-Malic acid is, in fact, involved in the metabolic life of the Krebs cycle and increases the levels of oxygen in the muscles.
Since its intake through food, a wide range of benefits is therefore available:
-L-Malic acid improves the food energy
-L-Malic acid increases the physical strength in those who carry out intense sports activities
-L-Malic acid reduces the perception of pain due to chronic fibromyalgia
ADVANTAGES:
-L-Malic acid in foods provides a number of benefits such as:
-L-Malic acid supports the body in releasing energy from food;
-Increases the physical endurance of athletes and athletes;
-Provides valuable support during the hypoxic phase of training;
-L-Malic acid can relieve the symptoms of chronic fibromyalgia, which reduces pain.
-For the above reasons, L-Malic acid is highly recommended to consume foods containing malic acid, which is believed to increase physical performance, especially in cases of oxygen deficiency in the cells, for those who do intense, competitive or professional sports.
-L-Malic acid may prolong sports performance during the hypoxic phases of training, especially when taken as a nutritional supplement.
CHEMICAL PROPERTIES:
-L-Malic acid is nearly odorless (sometimes a faint, acrid odor).
-This compound has a tart, acidic, nonpungent taste.
FUNCTION:
L-Malic acid has a clean, soft, smooth, persistent sourness.
L-Malic acid has flavor enhancing and blending abilities.
L-Malic acid helps the formulator because it intensifies the effect of many flavors in foods or beverages and reduces the amount of flavoring usually needed.
L-Malic acid blends different flavors resulting in a versatile flavor experience, enhancing the effect of some flavors and improving aftertaste.
L-Malic acid enhances the explosion and aromaticity of certain taste notes in some beverage applications, and enhances and deepens appetizing flavors such as cheese and chili peppers in snack food coatings.
L-Malic acid expands the flavor profile of many products, providing a richer, more natural flavor experience.
L-Malic acid has a high resolution ratio.
L-Malic acid has lower hygroscopicity than citric or tartaric acids.
It has a lower melting point than other acids for easier incorporation into melted candies.
L-Malic acid has good chelating properties with metal ions.
L-Malic acid has two stereoisomeric forms, and only the L-isomer is naturally present.
Commercial production of malic acid is done by hydration of fumaric acid or maleic acid, and the resulting product is L-Malic acid.
PRODUCTION:
Racemic L-Malic acid is produced industrially by the double hydration of maleic anhydride.
In 2000, American production capacity was 5000 tons per year.
Both enantiomers may be separated by chiral resolution of the racemic mixture, and the (S)- enantiomer may be specifically obtained by fermentation of fumaric acid.
Malic acid was important in the discovery of the Walden inversion and the Walden cycle, in which (−)-malic acid first is converted into (+)-chlorosuccinic acid by action of phosphorus pentachloride.
Wet silver oxide then converts the chlorine compound to (+)-malic acid, which then reacts with PCl5 to the (−)-chlorosuccinic acid.
The cycle is completed when silver oxide takes this compound back to (−)-malic acid.
MECHANISM OF ACTION:
L-Malic acid is absorbed from the gastrointestinal tract from whence it is transported via the portal circulation to the liver.
There are a few enzymes that metabolize malic acid.
L-Malic acid enzyme catalyzes the oxidative decarboxylation of L-malate to pyruvate with concomitant reduction of the cofactor NAD+ (oxidized form of nicotinamide adenine dinucleotide) or NADP+ (oxidized form of nicotinamide adenine dinucleotide phosphate).
These reactions require the divalent cations magnesium or manganese.
Three isoforms of malic enzyme have been identified in mammals: a cytosolic NADP+-dependent malic enzyme, a mitochondrial NADP+- dependent malic enzyme and a mitochondrial NAD(P)+-dependent malic enzyme.
The latter can use either NAD+ or NADP+ as the cofactor but prefers NAD+.
Pyruvate formed from malate can itself be metabolized in a number of ways, including metabolism via a number of metabolic steps to glucose.
L-Malic acid can also be metabolized to oxaloacetate via the citric acid cycle.
The mitochondrial malic enzyme, particularly in brain cells may play a key role in the pyruvate recycling pathway, which utilizes dicarboxylic acids and substrates, such as glutamine, to provide pyruvate to maintain the citric acid cycle activity when glucose and lactate are low.
SAFETY:
L-Malic acid is used in oral, topical, and parenteral pharmaceutical formulations in addition to food products, and is generally regarded as a relatively nontoxic and nonirritant material.
However, concentrated solutions may be irritant.
STORAGE:
L-Malic acid is stable at temperatures up to 150°C.
At temperatures above 150°C it begins to lose water very slowly to yield fumaric acid; complete decomposition occurs at about 180°C to give fumaric acid and maleic anhydride.
L-Malic acid is readily degraded by many aerobic and anaerobic microorganisms.
Conditions of high humidity and elevated temperatures should be avoided to prevent caking.
The effects of grinding and humidity on malic acid have also been investigated.
The bulk material should be stored in a well-closed container, in a cool, dry place.
SYNONYM:
DL-malic acid
6915-15-7
2-Hydroxysuccinic acid
2-Hydroxybutanedioic acid
617-48-1
malate
Butanedioic acid, hydroxy-
hydroxysuccinic acid
Kyselina jablecna
Deoxytetraric acid
hydroxybutanedioic acid
Pomalus acid
Malic acid, DL-
Musashi-no-Ringosan
alpha-Hydroxysuccinic acid
Hydroxybutandisaeure
dl-Hydroxybutanedioic acid
Caswell No. 537
Monohydroxybernsteinsaeure
Succinic acid, hydroxy-
2-Hydroxyethane-1,2-dicarboxylic acid
Kyselina jablecna [Czech]
FDA 2018
DL-2-hydroxybutanedioic acid