monoacylglycerides

Monoacylglycerides are glycerol molecules bearing a single fatty acid attached by an ester bond to one of glycerol’s three hydroxyl groups. Because the fatty acid can occupy either the first or second hydroxyl position, two positional isomers exist: 1-monoacylglycerol and 2-monoacylglycerol. In practice, 2-monoacylglycerol is the main product of triglyceride digestion by pancreatic lipase, though small amounts of the 1-position isomer can also form.

Monoacylglycerides occur naturally as intermediates of fat digestion and can be prepared industrially by glycerolysis or esterification of glycerol with fatty acids, or by transesterification of triglycerides. They are widely used as food emulsifiers and texturizers and are commonly sold as mono- and diglycerides of fatty acids (E471).

During digestion, pancreatic lipase preferentially hydrolyzes triglycerides at the sn-1 and sn-3 positions, yielding predominantly 2-monoacylglycerol and free fatty acids, which are absorbed by the intestines. Within enterocytes, MAGs may be re-esterified to form triglycerides for chylomicron assembly or hydrolyzed to glycerol and fatty acids for energy or resynthesis elsewhere.

Chemically, MAGs are amphiphilic, which underpins their role as emulsifiers. They help stabilize oil-in-water emulsions, influence texture in baked goods and dairy products, and can function as partial fat replacers in reduced-fat formulations.

Regulatory agencies widely recognize monoacylglycerides as food ingredients. They are generally regarded as safe when used within approved limits and are listed in many jurisdictions as mono- and diglycerides of fatty acids (E471).