ω-3 Polyunsaturated fatty acids (PUFAs)

such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)

have some pharmacological and physiological effects on human health. They are mainly from fish oil. The present study was made to enrich PUFAs in glyceride from fish oil by the selective hydrolysis of immobilized lipase. The method of combining adsorption with crosslinking was used for Aspergillus oryzae lipase immobilization. Lipase was immobilized by adsorption onto diatomite at 25℃ for 6 h and then crosslinked with 0.5% glutaraldehyde for 1.5 h. The effects of hydrolysis of fish oil with this immobilized lipase were studied.The optimal temperature was 38℃

optimal rotating speed was 200 r8226;min-1

the optimal ratio of oil to water was 1∶1

the optimal amount of lipase was 150 U8226;(g oil)-1

and the optimum time for concentrating PUFAs in glyceride was 24 h. The results showed that under this hydrolysis conditions the contents of EPA

DHA and EPA+DHA in glyceride were increased respectively from 3.0% to 7.0%

from 4.3% to 14.5% and from 7.3% to 21.5%.