Preparation of 1, 3-dioleoyl-2-palmitoylglycerol-rich structured lipids from basa catfish oil: Combination of fractionation and enzymatic acidolysis

摘要

1,3-dioleoyl-2-palmitoylglycerol (OPO)-rich structured lipids were successfully prepared from basa catfish oil by a two-step process, namely, fractionation to enrich triacylglycerol (TAG) fractions with high content of sn-2 palmitic acid and Lipozyme RM IM-catalyzed acidolysis of the fractionated products with free fatty acids from high oleic acid sunflower oil to increase the content of OPO. In the first step, the content of sn-2 palmitic acid of solid fraction was increased from 49.34 to 60.42% after programmed temperature treatment of basa catfish oil at 60 degrees C for 30 min followed by 30 degrees C for 12 h. In the second step, the solid fraction was used for transesterification with the fatty acids from high oleic acid sunflower oil and the conditions selected for acidolysis reactions were as follows: substrate molar ratio, 1: 6 (fatty acids/solid fat); enzyme load, 12 wt%; reaction temperature, 50 degrees C; and reaction time, 2 h. Under these conditions, the contents of sn-2 plamitic acid and sn-1, 3 oleic acid were 57.80 and 79.21%, respectively, and the content of POO was increased from 20.13% in the basa catfish oil to 43.80% in the enzymatic product, which indicated high content of OPO.