Where Does Malic Acid Come From?
Malic acid is a naturally occurring organic compound found mostly in unripe fruits. It is a white crystal in solid state and is very soluble in water. The refreshing and pleasant experience of biting into a juicy cherry or apple is partially caused by malic acid. Malic acid is used to create distinct taste experience in foods, drinks and concoctions by blending it with a number of food acids, flavors, sweeteners and sugars.
Other People Are Reading
-
History
-
Carl Wilhelm Scheele first isolated malic acid from apple juice in 1785. The term "malic acid" was first proposed by Antoine Lavoisier in 1787. It was actually derived from a Latin word meant for apple.
Biological Sources
-
Malic acid is a dicarboxylic acid, the key ingredient in many tart and sour foods. Malic acid occurs naturally in all eukaryotic cells. Malic acid is derived from food sources and produced in metabolic cycles (citric acid cycle) in both plants and animals, including humans. Large amounts of malic acid are produced in the human body on a daily basis. The most prolific source of malic acid is fruits and vegetables. Among fruits, apples are the richest source of malic acid, this is the reason malic acid is also called "apple acid."
-
Biochemistry
-
Malic acid plays an important part in biochemistry. In the environment, malic acid displays "homochirality" (homochirality refers to molecules that may or may not be from the same compound but similar groups follow a distinct pattern in their arrangements around a central atom). Malic acid is a source of carbon dioxide in the carbon fixation of Kelvin cycle. It is also formed in the citric acid cycle during respiration.
Plant Source
-
Autotrophs--organisms that are able to make their own food--produce malic acid in their guard cells from starch. Hence, it plays an important role in the opening and closing of stomata--small pores on the surface of plants--during transpiration. A buildup of malic acid usually results in a low water potential. It will subsequently draw more water into the guard cells in order to increase its water pressure. This will induce the opening of stomata.
Grape
-
Malic acid also occurs in grapes. It confers the sourness to green grapes and tartness to wine. The amount of tart taste decreases with increasing ripeness of fruit because malic acid is converted into mild lactic acid through malolactic fermentation.
-
