ENRICHMENT OF POLYUNSATURATED FATTY-ACIDS WITH GEOTRICHUM-CANDIDUM LIPASE

Three lipases, isolated previously in our laboratory, each with different fatty acid and positional specificities, and a known lipase from Candida cylindracea were screened for concentrating docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids in glycerides. Geotrichum candidum lipase was found to be suitable for their concentration in glycerides. Tuna oil was treated at 30 degrees C with this lipase for 16 h, and 33.5% hydrolysis resulted in the production of glycerides containing 48.7% of DHA and EPA. The hydrolysis was not increased despite adding further lipase, so the glycerides were extracted, and the reaction was repeated. The second hydrolysis produced glycerides containing 57.5% of DHA and EPA in a 54.5% yield, with recovery of 81.5% of initial DHA and EPA. Of the total glycerides, 85.5% were triglycerides. These results showed that G. candidum lipase was effective in producing glycerides that contained a high concentration of polyunsaturated fatty acids in good yield.