monounsaturated

Monounsaturated refers to a class of chemical compounds that contain exactly one carbon–carbon double bond in their hydrocarbon chain. In fatty acids, monounsaturated fatty acids (MUFAs) have one double bond per molecule, distinguishing them from saturated fatty acids (no double bonds) and polyunsaturated fatty acids (two or more double bonds). Common MUFAs include oleic acid (C18:1) and palmitoleic acid (C16:1). Oleic acid is abundant in olive oil and many Mediterranean foods.

In nutrition, MUFAs are considered healthier fats when used in place of saturated fats. Replacing saturated fat with MUFAs can modestly lower LDL cholesterol and may improve HDL cholesterol; observational studies associate high MUFA intake with reduced cardiovascular risk, while randomized trials show variable effects depending on the overall dietary pattern. The Mediterranean diet emphasizes MUFAs from olive oil, nuts, and avocados.

Chemically, the double bond in MUFAs is typically in the cis configuration in natural fats, contributing to a kink that affects melting point and texture. Trans-MUFA fats can form through partial hydrogenation or in some ruminant fats, and are associated with adverse health effects. MUFAs are generally more stable than polyunsaturated fats but less so than saturated fats, influencing their culinary use and shelf life.

In food labeling, MUFAs are reported as part of total fat content, with separate reporting often including saturated, monounsaturated, and polyunsaturated fats. The omega-9 family is a common category of MUFAs, with oleic acid being a prominent member.