One-step extraction and concentration of polyunsaturated fatty acids from fish liver

The fatty acids (FA) eicosapentaenoic acid (20:5 omega-3; EPA) and docosahexaenoic acid (22:6 omega-3; DHA), which have several health benefits, have been concentrated from mako shark liver (Isurus oxyrinchus). The process was carried out in one single step, in which fish liver oil was simultaneously extracted, saponified and concentrated. Additionally, the polyunsaturated fatty acids (PUFA) concentrate was winterized to crystallize the remaining saturated FA, resulting in a further increase in the concentration of DHA and EPA. Two variables, temperature and water concentration in the saponification mixture, were optimized to increase the concentration of omega-3 PUFA. Best results were obtained at 12 degrees C and 0% water content in the mixture, obtaining 17.8% purity and 77.6% yield of EPA; DHA purity and yield were 33.3 and 82.2%, respectively.