Concentration of Docosahexaenoic Acid-containing Phospholipid through Lipozyme IM-mediated Hydrolysis

Abstract

A selective partial hydrolyses of egg-yolk lecithin from fish-oil fed hens and squid-skin lecithin were carried out with immobilized Rhizomucor miehei lipase (Lipozyme IM) in n-hexane media in order to concentrate docosahexaenoic acid (DHA) -containing phospholipids. DHA were abundant in phospholipid fractions that had recovered from the partial hydrolysates than the corresponding substrates i.e. egg-yolk lecithin and squid lecithin. Thus, it was clear that DHA ester bonds were less susceptible against hydrolysis than other fatty acid ester bonds. Optimum water activity (a_w) for Lipozyme IM to concentrate DHA-containing phospholipids was a_w=0.44. Under this a_w, DHA showed to three fold increase compared to that of the original egg-yolk lecithin from fish-oil fed hens, after 8 h reaction at 40°C. Water activity-controlled partial hydrolysis with Lipozyme IM was borned out to be a useful method for concentrating functional phospholipids.