Production of stearidonic acid-rich triacylglycerol via a two-step enzymatic esterification

Abstract The aim of this study was to synthesize stearidonic acid (SDA)-rich triacylglycerol (TAG) via a two-step lipase-catalyzed esterification under vacuum. SDA-rich fatty acid, which was prepared from echium oil via Candida rugosa lipase-catalyzed selective esterification, was used as the substrate. Two different immobilized lipases, Novozym 435 from Candida antarctica and Lipozyme TL IM from Thermomyces lanuginosus , were employed for the synthesis of SDA-rich TAG. In the first step, Novozym 435-catalyzed esterification of the SDA-rich fatty acid with glycerol was carried out for 2 h. In the second step, Lipozyme TL IM-catalyzed esterification of the reaction mixture from the first step was performed for an additional 10 h. The optimal reaction conditions for the second step were a temperature of 65 °C, an enzyme loading of 20%, and a vacuum of 0.7 kPa. Consequently, the maximum TAG conversion of ca. 86.4 wt% was obtained after 12 h via a two-step lipase-catalyzed esterification.