Lipase-catalyzed two-step hydrolysis for concentration of acylglycerols rich in ω-3 polyunsaturated fatty acids

In this study, enzymatic two-step hydrolysis of tuna oil was performed to release saturated (SFAs) and monounsaturated fatty acids (MUFAs) from triacylglycerols (TAGs) to obtain acylglycerols rich in ω-3 polyunsaturated fatty acids (PUFAs). At the first step, AY "Amano" 400SD was chosen to mainly hydrolyze MUFAs from tuna oil under the conditions as described previously. At the second step, second hydrolysis by Candida antarctica lipase A (CAL-A) was conducted to mainly remove SFAs in acylglycerols isolated from the hydrolysate obtained at the first step. The second hydrolysis conditions were optimized. Under the optimum conditions, the content of ω-3 PUFAs in acylglycerols increased from initial 34.3% in tuna oil to 57.65% after initial hydrolysis and further to 68.94% after second hydrolysis. The most important finding in this study is that AY "Amano" 400SD and CAL-A selectively hydrolyze MUFAs and SFAs, respectively, which may have the potential application for PUFAs concentration.