oleic

Oleic acid, or simply oleic, is a monounsaturated fatty acid with the chemical formula C18H34O2. Its systematic name is cis-9-octadecenoic acid, reflecting a single cis double bond at carbon 9 in an eighteen-carbon chain. In biological lipids, it occurs as the acid component of triglycerides and phospholipids, and it is a principal monounsaturated fatty acid in many edible fats and oils.

Oleic acid is most abundant in olive oil, where it can comprise about 55 to 83 percent of the fatty acids. It is also found in canola, peanut, and sunflower oils, as well as in animal fats. The naturally occurring isomer is cis-9-oleic acid; the trans isomer, elaidic acid, is formed mainly during some industrial hydrogenation processes or in certain processed foods.

Chemically, oleic acid is an 18-carbon unsaturated fatty acid with one cis double bond. It is a liquid at room temperature. In humans, oleic acid is not considered essential, since the body can synthesize it, but it is a common component of cellular membranes and energy stores. Diets that replace saturated fats with oleic acid-containing fats are associated with favorable changes in blood lipids in some studies.

Commercially, oleic acid serves as a versatile precursor for soaps, detergents, lubricants, and various esters. It is used to produce biodiesel esters, cosmetics, and polymer applications. The glyceride form is the primary form in edible fats and oils, contributing to texture and flavor.