Enzymatic Production of ABA-Type Structured Lipids Containing Omega-3 and Medium-Chain Fatty Acids: Effects of Different Acyl Donors on the Acyl Migration Rate

Enzymatic production of ABA-type structured lipids (SLs) containing marine-derived long-chain polyunsaturated fatty acid (n-3 PUFA) and medium-chain fatty acids was investigated. Response surface methodology was applied to optimize the reaction system and evaluate the effects of reaction factors and different acyl donors namely n-3 PUFA and n-3 PUFA ethyl esters (n-3 PUFA-EE). Well-fitting models were obtained by multiple regressions with backward elimination. For both n-3 PUFA and n-3 PUFA-EE systems, both reaction time and enzyme load had significant (P < 0.05) positive effects on incorporation and acyl migration rate. Water content were found to have significant (P < 0.05) negative effects on incorporation but positive effects on acyl migration in the n-3 PUFA-EE system. Although there were no significant difference in terms of incorporation rate, n-3 PUFA were found to produce five times higher acyl migration rate than n-3 PUFA-EE. The optimal reaction conditions to produce high yield of ABA-type SLs of 49.6% with low acyl migration rate of 2.6% were as follows: n-3 PUFA-EE as acyl donors; enzyme load, 6 wt.%; reaction time, 6 h; and water content, 3 wt.%. Thus, n-3 PUFA-EE was found to be a suitable acyl donor to produce high yield of ABA-type SLs with low acyl migration rate.