Purification process for cod liver oil polyunsaturated fatty acids

The polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), which have several pharmaceutical properties, have been purified from cod liver oil. The process consisted o f four main steps: (i) saponification of the oil, (ii) use of urea inclusio n adducts method to obtain PUFA, (iii) PUFA methylation, and (iv) argentati on silica gel column chromatography of the methylated PUFA. Argentation sil ica get chromatography yielded highly pure DHA in the process (100% purity, 64% yield). For EPA, the recovery in the combined process was 29.6%, and t he final purity was 90.6%, owing to the simultaneous elution of other polyu nsaturated fatty esters. The recovery in the urea inclusion method was stro ngly enhanced by application of orbital agitation during the crystallizatio n process, in which EPA yield increased from 60-70% without agitation to 90 -97% at 800 rpm; stearidonic acid (18:4n-3) yield ranged from 60-75% withou t agitation to 87-95% at 800 rpm, and DHA yield varied from 53-73% without agitation to 85-99% at 800 rpm.