Evaluation of the use of surfactants as additives in enzymatic glycerolysis reactions

Abstract

MAGs and DAGs are widely used as emulsifiers in many industries. During glycerolysis reactions for their production, the immiscibility of the glycerol and the oil phases is an important drawback for practical purposes. For overcoming this problem, the use of a food grade surfactant can be an important alternative to improve system homogeneity, leading to high TAGs conversion in short reaction times. On the other hand, food grade surfactants have bonds that could be modified by lipases. The main interest of this work was to qualitatively verify the reactivity of different Tween and soy lecithin used as additives in glycerolysis reactions in the presence of Candida antarctica B lipase. The biocatalyst had activity toward all tested surfactants in the experimental conditions chosen for the tested reactions. Despite this, MAG and DAG could be produced when using Tween 85 as additive in the enzymatic glycerolysis of fish oil. Our results therefore suggest that tested Tween and soy lecithin can be used as surfactants in glycerolysis reactions, but one has to consider their reactivity in the presence of lipases. Practical applications: This work investigates the reactivity of synthetic (Tween) and natural (soy lecithin) surfactants in the presence of lipase during glycerolysis reactions. Tween 85 was further applied in different reaction media for a better understanding of the modifications it was undergoing. The biocatalyst had activity toward almost all tested surfactants in the experimental conditions chosen for the preliminary assays herein performed, as qualitatively verified by thin-layer chromatography. This result suggests that the use of phosphatides and polyoxyethylene esters as additives in glycerolysis systems has to be well evaluated as their enzymatic modification may generate problems during downstream processes for the recovery of the desirable products. The present report is part of a broader project aiming at building a platform to allow developing new processes for the production of emulsifiers through enzyme-catalyzed glycerolysis reaction. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.