Selective Hydrolysis of Fish Oil by Lipase to Concentrate n-3 Polyunsaturated Fatty Acids

Abstract

Six lipases were examined for concentrating the n-3 polyunsaturated fatty acid (n-3 PUFA) of two kinds of fish oil (cod liver oil and refined sardine oil). Although all lipases could increase the n-3 PUFA content of the remaining glycerides, Candida cylindracea and spergillus niger lipases gave glycerides with a more than two-fold increase in n-3 PUFA content over the original fish oils.
Candida cylindracea lipase seems the most promising with respect to recovery of triacylglycerol. Aspergillus niger lipase increased not only the docosahexaenoic acid (DHA) content but also eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA), although the absolute value of the latter was quite low. The effects of temperature (15-40°C) on the concentration of n-3 PUFA were investigated. Lower temperatures did not improve the concentration of n-3 PUFA, but prevented the development of an unpleasant odor in the product.