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

glyceride Glycerides, also 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 to form mo ...

s which are composed of a molecule of

glycerol Glycerol () is a simple triol compound. It is a colorless, odorless, sweet-tasting, viscous liquid. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pha ...

linked to a

fatty acid In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an ...

via an

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

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

s such as

olive oil Olive oil is a vegetable oil obtained by pressing whole olives (the fruit of ''Olea europaea'', a traditional Tree fruit, tree crop of the Mediterranean Basin) and extracting the oil. It is commonly used in cooking for frying foods, as a cond ...

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. Historica ...

and

cottonseed oil Cottonseed oil is cooking oil from the seeds of cotton plants of various species, mainly ''Gossypium hirsutum'' and ''Gossypium herbaceum'', that are grown for cotton fiber, animal feed, and oil. cottonseed, Cotton seed has a similar structure to ...

. 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 reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

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

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

diglyceride A diglyceride, or diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages. Two possible forms exist, 1,2-diacylglycerols and 1,3-diacylglycerols. Diglycerides are ...

s by diacylglycerol lipase; or as an intermediate in the alkanoylation of glycerol to form

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers specif ...

s. Several monoglycerides are pharmacologically active (e.g. 2-oleoylglycerol,

2-arachidonoylglycerol 2-Arachidonoylglycerol (2-AG) is an endocannabinoid, an endogenous agonist of the CB1 receptor and the primary endogenous ligand for the CB2 receptor. It is an ester formed from the omega-6 fatty acid arachidonic acid and glycerol. It is pres ...

). Industrial production is primarily achieved by a glycerolysis reaction between

triglycerides A triglyceride (from ''wikt:tri-#Prefix, tri-'' and ''glyceride''; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and oth ...

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 edible plants. Like animal fats, vegetable fats are ''mixtures'' of triglycerides. Soybean oil, grape seed oil, and cocoa butter are examples of seed ...

s or

animal fat Animal fats are lipids derived from animals which are used by the animal for a multitude of functions, or can be used by humans for dietary, sanitary, and cosmetic purposes. Depending on the temperature of the fat, it can change between a solid s ...

Uses

Monoglycerides are primarily used as

surfactant Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word ''surfactant'' is a Blend word, blend of "surface-active agent", coined in ...

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 Mono- and diglycerides of fatty acids ( E471) are a naturally occurring class of food additive composed of diglycerides and monoglycerides used as an emulsifier in foods such as infant formula, fresh pasta, jams and jellies, chocolate, creams ...

), which helps to prevent mixtures of oils and water from separating. They are also often found in bakery products, beverages,

ice cream Ice cream is a frozen dessert typically made from milk or cream that has been flavoured with a sweetener, either sugar or an alternative, and a spice, such as Chocolate, cocoa or vanilla, or with fruit, such as strawberries or peaches. Food ...

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 tex ...

shortening Shortening is any fat that is a solid at room temperature and is used to make crumbly pastry and other food products. The idea of shortening dates back to at least the 18th century, well before the invention of modern, shelf-stable vegetable ...

, whipped toppings,

margarine Margarine (, also , ) is a Spread (food), 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 ...

, spreads, and peanut butter, and

confection Confectionery is the art of making confections, or sweet foods. Confections are items that are rich in sugar and carbohydrates, although exact definitions are difficult. In general, however, confections are divided into two broad and somew ...

s. 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, 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

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

Synthesis

Uses

Examples

See also

References