Immobilization of lipase for two-step hydrolysis to enrich n-3 polyunsaturated fatty acids in glyceride form.

N-3 Polyunsaturated fatty acids (PUFAs) in acylglycerol form offer physiological functions and high bioavailability, attracting industrial interest. This study evaluated six carriers for immobilizing free Candida cylindraceav lipase AY "Amano" 400SD and Candida antarctica lipase A (CAL-A) to prepare n-3 PUFA-rich acylglycerols via a two-step enzymatic hydrolysis. Macroporous resin NKA-9 showed optimal immobilization performance, with the adsorption protein loading of 129.23 mg/g (AY "Amano" 400SD) and 107.33 mg/g (CAL-A). The optimized process was applied to fish oil, algae oil, and tuna oil with different fatty acid compositions. The n-3 PUFA content in the final acylglycerols increased from 38.16 % to 68.66 % in fish oil, from 47.84 % to 73.30 % in algae oil, and from 34.30 % to 70.64 % in tuna oil, confirming the effectiveness and broad applicability of the enzymatic approach. This study provided a reference for the industrial-scale production of n-3 PUFA oils, aiming for potential cost reduction and greener processing.