In biochemistry and nutrition, monounsaturated fats or MUFA (MonoUnsaturated Fatty Acid) are fatty acids that have a single double bond in the fatty acid chain and all of the remainder of the carbon atoms in the chain are single-bonded. By contrast, polyunsaturated fatty acids have more than one double bond.
Fatty acids are long-chained molecules having a methyl group at one end and a carboxylic acid group at the other end. Fatty acid viscosity (thickness) and melting temperature increases with decreasing number of double bonds. Therefore, monounsaturated fatty acids have a higher melting point than polyunsaturated fatty acids (more double bonds) and a lower melting point than saturated fatty acids (no double bonds). Monounsaturated fatty acids are liquids at room temperature and semisolid or solid when refrigerated.