Alpha hydroxy acid, or AHA, is a chemical compound made of hydrogen, carbon and oxygen structures. It is primarily derived from the sugar of milk, fruit and vegetable-like fruit, such as tomatoes. Because of their extensive use in a wide range of industries, AHAs are also synthetically created. However, they occur naturally in foods in the form of lactic acid, malic acid, citric acid, glycolic acid, sorbic acid and tartaric acid.
Lactic Acid
Lactic acid is naturally produced through a form of carbohydrate fermentation called lacto-fermentation, and was initially discovered through sour milk. While lactic acid is commonly known to occur in dairy products like yogurt, cottage cheese and leban, it’s also produced through the lacto-fermentation of nondairy foods such as sauerkraut, pickles and kimchi.
Lactic acid is also an acidulant. Acidulants are acidic substances added to products for flavor enhancement, preserving foods and stabilizing gels. Lactic acid is an additive used in various breads, meats and beverages. However, lactic acid is also used as an acidulant to bybass the lacto-fermentation process that occurs in foods like commercial dairy products, in order to control an item's quality and timely production.
Malic Acid
Malic acid is a product of metabolism in various plants. While malic acid is found in almost all fruits in varying degrees, it is usually associated with plums, apples and tomatoes. Malic acid is also used as an acidulant in numerous foods including jellies, chewing gum, candies, carbonated beverages and soy milk.
Citric Acid
Citric acid -- an organic acid discovered in 1784 -- is the primary component that gives fruit its tart taste. It is derived naturally from many citrus and noncitrus fruits including oranges, gooseberries, lemons, pineapples and grapefruits. Citric acid is an acidulant and is sometimes produced commercially by fermenting of sugar. It is used in an array of food products including carbonated beverages, drink mixes, jellies, canned and frozen food products. Citric acid is also an additive in the process of making various cheeses like mozzarella.
Glycolic Acid
Glycolic acid, also referred to as hydroxyacetic acid, is an odorless, colorless acid naturally found in sugar beets, cantaloupe, sugarcane, unripe grapes and pineapple. Glycolic acid functions as an acid and alcohol, so its use as an acidulant is predominately for nonfood items. For example, glycolic acid is used in many skin care and hair care products. Also, glycolic acid is used in industrial cleaners such as for concrete removers and cleaners, commercial food equipment cleaners and boiler system cleaners. Additionally, glycolic acid is used in leather tanning, oil refining and water treatment systems.
Sorbic Acid
Sorbic acid was originally discovered in 1816 and then later isolated in 1859. It occurs in the berries of rowan or mountain-ash trees -- members of the scientific genus Sorbus, from which sorbic acid’s name is derived. Sorbic acid is also an acidulant, used almost exclusively as preservative in many foods including wine, flour, carbonated drinks, jams and cheese.
Tartaric Acid
Tartaric acid, also referred to as dihydroxybutanedioic acid, is found in various fruits such as bananas and grapes, and is a byproduct of wine fermentation. It is one of the first, commercially wide-scale acidulants used, and is still added to a broad range of products from carbonated drinks to gelatin desserts.
References
- National Institutes of Health – National Library of Medicine: “Applications of hydroxy acids: classification, mechanisms, and photoactivity”; Andrija Kornhauser, etc.; November 2010
- Encyclopedia: Gale Encyclopedia of Alternative Medicine; Alpha Hydroxy; Paula Ford-Martin; 2005
- Encyclopedia: Dictionary of Food and Nutrition; Lactic Acid; David A. Bender; 2005
- Cooperative Purchasers: Acidulants
- Encyclopedia.com: Dictionary of Food and Nutrition; Malic Acid; David A. Bender; 2005
- Bartek Ingredients Inc.: Malic Acid
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