1 mol mol was added lipase derived from candida rugosa in a concentration of 30 u g of mixture and the resulting mixture was subjected to selective transesterification at 30 u00b0 c for 16 hours followed by molecular distillation according to the usual method to give a free fatty acid and a lauryl ester fractions the fatty acid fraction of the distillate containing 86 3 by weight of 10trans 12cis cla the distillate fraction of the molecular distillation thus obtained was subjected to the addition of urea in ethanol according to the conventional method and subsequently to filtration under gradual cooling to give 95 7 by weight of 10trans 12cis cla the lauryl ester fraction obtained in example 1 was subjected to hydrolysis in the presence of alkali naoh according to the conventional method to 760 g of a mixture of the free fatty acid fraction thus obtained and lauryl alcohol 1 1 mol mol was added lipase derived from candida rugosa in a concentration of 10 u g of mixture and the resulting mixture was subjected to selective transesterification at 30 u00b0 c for 16 hours to give an oil layer in a yield of 717 g the reaction product was subjected to molecular distillation according to the conventional method and the lauryl ester fractions collected were subjected to hydrolysis under the alkaline condition according to the conventional method to give the 9cis 11trans cla in a yield of 159 g 92 2 by weight male oletf rats 7 weeks old an animal model of non insulin dependent diabetes mellitus were assigned to three groups that were fed ad libitum with a semisynthetic diet ain 76 supplemented with 0 5 high linoleic safflower oil rinoru oil mills co ltd.