Hydrolysis principle of edible oil catalyzed by phospholipase A1 (Lecitase Ultra)(II): stereoselectivity and hydrolysis route

Phospholipase A1(Lecitase Ultra)(PLA1) was deduced to possess Sn-1,3-stereoselectivity to triacylglycerol by comparing the composition of the released fatty acid by PLA1 with that by pancreatic lipase during partial hydrolysis of soybean oil.The equilibrium constant of partial hydrolysis of soybean oil with PLA1 was determined.By analyzing the composition of hydrolysate,it was deduced that at the initial stage,triacylglycerol(TAG) was hydrolyzed according to the hydrolysis route of 1,2-diacylglycerol(DAG),and the major portion of DAG was 1,2-DAG.Along with the increase of 1,2-DAG content,TAG was hydrolyzed according to the hydrolysis route of 1,3-DAG at the same time.At the last stage,TAG was mainly hydrolyzed by route of 1,3-DAG and the concentration of 1,3-DAG decreased gradually because 1,3-DAG was hydrolyzed more easily.