Preparation of glycerides enriched with n-3 long-chain polyunsaturated fatty acids by Thermomyces lanuginosus lipase-catalyzed hydrolysis of tuna oil

Abstract

n-3 Long-chain polyunsaturated fatty acids (LC-PUFAs) in glyceride form have attracted much attention due to their nutritional value and high bioavailability. In this work, Thermomyces lanuginosus lipase (TL 100 L) was used to selectively hydrolyze tuna oil for preparing glycerides enriched with n-3 LC-PUFAs. Effects of reaction variables on the hydrolysis reaction were optimized by response surface methodology, and the optimal conditions were as follows: reaction temperature 54 °C, enzyme load 3%, reaction time 6 h, mass ratio of water to tuna oil 1.5:1. Under these conditions, the resulting degree of hydrolysis was 55.01%, and the total content of eicosapentaenoic acid and docosahexaenoic acid in the glyceride fraction was found to be 46.39%. The final product was mainly composed of diacylglycerols (53.93%) and triacylglycerols (34.58%) after removal of the free fatty acids. This paper provides a simple and suitable method for industrial production of glycerides enriched with n-3 LC-PUFAs.