Interesterification of Butter Fat by Lipase From Mucor Miehei in Microemulsion System

Butter fat was interesterified in a microemulsion system containing Brig 35 as surfactant and 1‐heptanol as co‐surfactant at 1% water (v/v), using commercial microbial lipase from Mucor miehei. The interesterified triacylglycerols were separated and purified by preparative liquid chromatography on a silica gel G column. The purified triacylglycerols were analytically separated by high performance liquid chromatography. The positional distribution of fatty acids was determined by deacylation using pancreatic lipase. The interesterification of triacylglycerols of butter fat, using the microemulsion system, within 48 h of incubation resulted in the increase of high molecular weight triacylglycerols containing the C18:0 fatty acid at the sn‐2 position, located originally at sn‐1,3 positions; this fatty acid was favorably interchanged with C14:0 and C18:1 at the sn‐2 position of the triacylglycerol molecules. The use of higher amounts of Brij 35 surfactant (> 3.3 mM) suppressed the acyl exchange reaction.