FATTY-ACID SELECTIVITY OF LIPASES - GAMMA-LINOLENIC ACID FROM BORAGE OIL

The gamma-linolenic acid (Z,Z,Z-6,9,12-octadecatrienoic acid, CLA) pre sent in borage oil free fatty acids was concentrated in esterification reactions that were catalyzed by several preparations of the acyl-spe cific lipase of Geotrichum candidum. In this manner, a 95% recovery of the CLA originally present in borage oil (25% CLA) was obtained as a highly enriched fatty acid fraction with a GLA content of >70%. Other fatty acids concentrated in this fraction were the monounsaturated fat ty acids with chainlengths of C-20 and longer that were present in the oil. An immobilized preparation of G. candidum on silica gel also was used for the enrichment of GLA in borage oil. In this instance, a 75% recovery of GLA was obtained, and the supported lipase was reusable ( three cycles) with minimal loss in activity.