Method for producing a concentrate of eicosapentaenoic and docosahexaenoic acid esters

Process for obtaining a concentrate of esters of EPA and DHA from crude or refined marine oils, which comprises:

• a) contacting crude or refined marine oil with at least one alkali and water at a temperature no higher than 100° C. to obtain a mixture comprising saponified marine oil;
• b) contacting the saponified mixture with at least one organic solvents to form a refined phase comprising alkaline salts of fatty acids and an extracted phase;
• c) separating the extracted phase from the refined phase;
• d) mixing the refined phase with an aqueous solution of an acid to form a non aqueous phase comprising fatty acids and an aqueous phase;
• e) separating the aqueous phase of the non-aqueous phase;
• f) mixing the separated non aqueous phase with an alcohol and an esterification catalyst at a temperature of at most 150° C. until an esterified mixture comprising esters of fatty acids is obtained;
• g) removing the catalyst from the esterified mixture to obtain the catalyst-free esterified mixture;
• h) removing any solvents from the catalyst-free esterified mixture to obtain esters of fatty acids, and
• i) distilling the esters of fatty acids in a short path distillation column at a temperature of at most 180° C. and a pressure of less than 1 mbar to obtain a concentrate comprising esters of EPA and DHA.