Highly concentrated omega-3 fatty acid ethyl esters by urea complexation and molecular distillation.

Abstract

Raya liver deodorized oil contains high concentrations of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). The present study investigated the processes of urea complexation (UC) and molecular distillation (MD) to determine the most adequate operation conditions for each process, separately and together, aiming to obtain highly concentrated EPA, DPA and DHA ethyl esters with chemical indicator values permitted by the current legislation for edible oils. In the second stage of MD, a concentration of 820.27 g kg-1 in the distillate and 951.06 g kg-1 of omega-3 fatty acid ethyl esters in the residue was obtained. The distillate showed values of free fatty acids, peroxide and p-anisidine lower than the maximum allowed for edible oils in accordance with the current legislation. The use of UC and MD together has revealed a significant improvement in the total concentration of omega-3 fatty acid ethyl esters in the final product and good application prospects. © 2018 Society of Chemical Industry.