Enrichment of omega-3 fatty acids in cod liver oil via alternate solvent winterization and enzymatic interesterification

Enrichment of omega-3 fatty acids in cod liver oil via alternate operation of solvent winterization and enzymatic interesterification was attempted. Variables including separation method, solvent, oil concentration, time and temperature were optimized for the winterization. Meanwhile, Novozyme 435, Lipozyme RM IM and Lipozyme TL IM were screened for interesterification efficiency under different system air condition, time and temperature. In optimized method, alternate winterization (0.1 g/mL oil/acetone, 24 h, −80 °C, precooled Büchner filtration) and interesterification (Lipozyme TL IM, N2 flow, 2.5 h, 40 °C) successfully doubled the omega-3 fatty acid content to 43.20 mol%. 1H NMR was used to determine omega-3 fatty acid content, and GC-MS to characterize oil product, which mainly contained DHA (15.81 mol%) and EPA (20.23 mol%). The proposed method offers considerable efficiency and reduce production cost drastically. Oil produced thereof is with high quality and of particular importance for the development of omega-3 based active pharmaceutical ingredients.