Monoglycerides (also: acylglycerols or monoacylglycerols) are a class of

glyceride Glycerides, more correctly known as acylglycerols, are esters formed from glycerol and fatty acids, and are generally very hydrophobic. Glycerol has three hydroxyl functional groups, which can be esterified with one, two, or three fatty acids ...

s which are composed of a molecule of

glycerol Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known ...

linked to a

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, f ...

via an

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

bond. As glycerol contains both primary and secondary alcohol groups two different types of monoglycerides may be formed; 1-monoacylglycerols where the fatty acid is attached to a primary alcohol, or a 2-monoacylglycerols where the fatty acid is attached to the secondary alcohol.

Synthesis

Monoglycerides are produced both biologically and industrially. They are naturally present at very low levels (0.1-0.2%) in some seed oils such as

olive oil Olive oil is a liquid fat obtained from olives (the fruit of ''Olea europaea''; family Oleaceae), a traditional tree crop of the Mediterranean Basin, produced by pressing whole olives and extracting the oil. It is commonly used in cooking: ...

rapeseed oil Close-up of canola blooms Canola flower Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historicall ...

and cottonseed oil. They are biosynthesized by the enzymatic

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysi ...

triglyceride A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''tri-'' and ''glyceride''). Triglycerides are the main constituents of body fat in humans and other vertebrates, as ...

s by

lipoprotein lipase Lipoprotein lipase (LPL) (EC 3.1.1.34, systematic name triacylglycerol acylhydrolase (lipoprotein-dependent)) is a member of the lipase gene family, which includes pancreatic lipase, hepatic lipase, and endothelial lipase. It is a water-solubl ...

and the enzymatic hydrolysis of diglycerides by diacylglycerol lipase; or as an intermediate in the alkanoylation of glycerol to form fats. Several monoglycerides are pharmacologically active (e.g. 2-oleoylglycerol, 2-arachidonoylglycerol). Industrial production is primarily achieved by a glycerolysis reaction between triglycerides and glycerol. The commercial raw materials for the production of monoacylglycerols may be either

vegetable oil Vegetable oils, or vegetable fats, are oils extracted from seeds or from other parts of fruits. Like animal fats, vegetable fats are ''mixtures'' of triglycerides. Soybean oil, grape seed oil, and cocoa butter are examples of seed oils, or f ...

s or

animal fat Animal fats and oils are lipids derived from animals: oils are liquid at room temperature, and fats are solid. Chemically, both fats and oils are composed of triglycerides. Although many animal parts and secretions may yield oil, in commerci ...

Uses

Monoglycerides are primarily used as

surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsion#Emulsifiers , ...

s, usually in the form of

emulsifiers An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Although ...

. Together with diglycerides, monoglycerides are commonly added to commercial food products in small quantities as "E471" (s.a. Mono- and diglycerides of fatty acids), which helps to prevent mixtures of oils and water from separating. The values given in the nutritional labels for total fat, saturated fat, and ''trans'' fat do not include those present in mono- and diglycerides as fats are defined as being triglycerides. They are also often found in bakery products, beverages,

ice cream Ice cream is a sweetened frozen food typically eaten as a snack or dessert. It may be made from milk or cream and is flavoured with a sweetener, either sugar or an alternative, and a spice, such as cocoa or vanilla, or with fruit such as ...

chewing gum Chewing gum is a soft, cohesive substance designed to be chewed without being swallowed. Modern chewing gum is composed of gum base, sweeteners, softeners/ plasticizers, flavors, colors, and, typically, a hard or powdered polyol coating. Its t ...

shortening Shortening is any fat that is a solid at room temperature and used to make crumbly pastry and other food products. Although butter is solid at room temperature and is frequently used in making pastry, the term ''shortening'' seldom refers to b ...

, whipped toppings,

margarine Margarine (, also , ) is a spread used for flavoring, baking, and cooking. It is most often used as a substitute for butter. Although originally made from animal fats, most margarine consumed today is made from vegetable oil. The spread was or ...

, spreads and peanut butter, and confections. In bakery products, monoglycerides are useful in improving loaf volume and texture, and as antistaling agents. Monoglycerides are used to enhance the physical stability towards creaming in milk beverages.

Examples

Glyceryl_laurate.png,

Monolaurin Monolaurin (abbreviated GML; also called glycerol monolaurate, glyceryl laurate, and 1-lauroyl-glycerol) is a monoglyceride. It is the mono-ester formed from glycerol and lauric acid. Its chemical formula is C15H30O4. Uses Monolaurin is most comm ...

, commonly used in cosmetics and as a food additive GlycMonoStear-PlainSVG.svg, Glycerol monostearate, used in foods as a thickening, emulsifying, and preservative agent File:1,3-Dihydroxy-2-propanyl_2-hydroxyoctadecanoate.svg, Glyceryl hydroxystearate, found in a variety of cosmetic and skin care products.

References

{{Glycerides Fatty acid esters Lipids ja:モノアシルグリセロール

Synthesis

Uses

Examples

See also

References