Preparation of Triacylglycerol Molecular Species by Interesterification Using Endocellular Lipase in n-Hexane

The interesterification of triacylglycerol with fatty acid was done to prepare triacylglycerol molecular species. Optimum operating conditions for the interesterification using a 1,3-positional specific endocellular lipase from Rhizopus japonicus NR400 in a batch system were investigated. The reaction was done at 40°C for 5 hr in the following system: Trioleoylglycerol-palmitic acid = 1:3.5 (mol/mol), 10 ml n-hexane/g trioleoylglycerol, and 2500 units of enzyme/g trioleoylglycerol. Under these conditions, the content of palmitoyl groups in 1,3-positions of triacylglycerol was about 60 mol%. Additional interesterification (2-cycle reaction) using palmitic acid and the novel triacylglycerol prepared by one-step interesterification (1-cycle reaction) resulted in a preparation of highly pure 1,3-dipalmitoyl-2-oleoylglycerol.