Preparation of medium- and long-chain triacylglycerols rich in n-3 polyunsaturated fatty acids by bio-imprinted lipase-catalyzed interesterification.

ABSTRACT

Medium and long-chain triacylglycerol (MLCT) rich in n-3 polyunsaturated fatty acids (PUFAs) were obtained in three-hour interesterification of fish oil with medium-chain triacylglycerol (MCTs), using lipase bio-imprinted with surfactant as a catalyst. Initially, for bio-imprinted lipase preparation, the interesterification reaction conditions were optimized, resulting in a lipase with 1.47 times higher catalytic activity compared to control (non-bio-imprinted). Afterwards, the reaction conditions for MLCT synthesis were optimized, using bio-imprinted lipase as a catalyst. The reaction reached equilibrium within first three hours at 70 °C temperature, 4 wt% lipase load, and molar ratio of substrate 11.5. Under these conditions, final product contained 18.52% MCT, 56.65% MLCT, and 24.83% long-chain triacylglycerol (LCT). To reduce the MCT content, a solvent extraction process was performed, yielding 2.42% MCT, 56.19% MLCT, and 41.39% LCT. The obtained structured lipids (SLs), enriched in n-3 PUFAs, offer significant health benefits, enhanced bioavailability, with potential applications in functional foods and nutraceuticals.