Enzymatic Esterification of River Catfish (Mystus nemurus) Fatty Acids to Enrich w-3 Polyunsaturated Fatty Acids

Abstract

The health benefits of w-3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexanoic acid (DHA, 22:6 n-3) are widely recognized and fish oil is an important source of polyunsaturated fatty acids. In this work, the effect of reaction conditions on esterification of river catfish (M. nemurus) free fatty acid (FFA) with oleyl alcohol, catalyzed by immobilized R. meihei lipase in order to enrich polyunsaturated fatty acids was studied. The fatty acid compositions of the reaction products were analyzed using gas chromatography on conversion to fatty acid methyl ester (FAME). The highest ratio of especially eicosapentaenoic acid and docosahexanoic acid was observed after 4 h and hexane (log P = 3.5) was found to be the best solvent. The highest especially eicosapentaenoic acid and docosahexanoic acid enrichment was achieved when the molar ratio of oleyl alcohol and free fatty acid is 2:1. In conclusion, river catfish-free fatty acid was successfully enriched by enzymatic esterification.