Lipase-catalyzed glycerolysis of anchovy oil in a solvent-free system: Simultaneous optimization of monoacylglycerol synthesis and end-product oxidative stability

Abstract

The production of mono- and diacylglycerols rich in polyunsaturated fatty acids is achieved in this study, by solvent-free glycerolysis of anchovy oil with lipase PS-DI from Burkholderia cepacia. Attention is focused on the oxidative stability of the reaction products, determined in terms of induction time (I_t). The effects of glycerol/triacylglycerol molar ratio, enzyme concentration, and reaction temperature on mono- and diacylglycerol production and I_t are all assessed. The operating conditions that optimized monoacylglycerol yields and oxidative stability were a glycerol/triacylglycerol ratio of 3/1, 9.0% (w/w) Lipase PS-DI, a stirring rate of 200 rpm, and a reaction time of 4 h, at 45.8 °C, producing a content of 24.8% and 51.9% of mono- and diacylglycerols, respectively, over an I_t of 1.41 h. The glycerolysis conditions determined by simultaneous optimization strategy increased the oxidative stability of the glycerolysis products by 68%, which rose from 0.84 h (individual optimization) to 1.41 h.