Response surface modelling of the production of ω-3 polyunsaturated fatty acids-enriched fats by a commercial immobilized lipase

Abstract

The aim of this study was to model the production of fats, enriched with ω-3 polyunsaturated fatty acids (ω-3 PUFA) for nutraceutical purposes, via the response surface methodology. These fats were obtained by transesterification of palm oil stearin (POS) with a concentrate (EPAX 2050TG) of triglycerides enriched with ω-3 PUFA and soybean oil, catalysed by a commercial immobilized Candida antarctica lipase (“Novozym 435”).The initial water activity (aw) of the biocatalyst, POS and EPAX 2050TG concentrations, time and temperature showed a significant effect on the transesterification reaction, as well as on the competing reactions of hydrolysis and lipid oxidation.Depending on the factors included, the transesterification reaction was described either by first- or second-order models.The production of free fatty acids, which is ascribed both to the hydrolytic reaction and the mechanism of lipase-catalysed transesterification, showed a second-order dependence on the initial aw of the biocatalyst.