Abstract
Commercially available preparations of CLA are composed of almost equal amounts of 9-cis ,11-trans(9c,11t)-CLA and 10-trans,12-cis(10t,12c)-CLA. Each isomer was fractionated and enriched, for availability as a food supplement, by a process comprising selective esterification with L-menthol by Candida rugosa lipase, distillation, and n -hexane extraction. The first selective esterification of CLA isomers was conducted with an equimolar amount of L-menthol at 30C. The oil phase of the reaction mixture was fractionated into an L-menthyl ester fraction (9c,11t-CLA rich) and an FFA fraction (10t,12c-CLA rich) by distillation. The FFA fraction was esterified again with an equimolar amount of L-menthol to enrich 10t,12c-CLA. The 10t,12c-CLA preparation was obtained as the resulting FFA fraction by distillation. 10t,12c-CLA was enriched to 91 percent with 40 percent recovery. To enrich 9c,11t-CLA, the L-menthyl ester fraction in the first esterification was chemically hydrolyzed, and the resulting FFA were esterified again with an equimolar amount of L-menthol. The 9c,11t-CLA preparation was obtained by chemical hydrolysis of the resulting L-menthyl ester fraction, followed by n-hexane extraction. 9c,11t-CLA was enriched to 94 percent with 42 percent recovery. This effective process for purification of CLA isomers using L-menthol is applicable to the production of food supplements.Commercially available preparations of CLA are composed of almost equal amounts of 9-cis ,11-trans(9c,11t)-CLA and 10-trans,12-cis(10t,12c)-CLA. Each isomer was fractionated and enriched, for availability as a food supplement, by a process comprising selective esterification with L-menthol by Candida rugosa lipase, distillation, and n -hexane extraction. The first selective esterification of CLA isomers was conducted with an equimolar amount of L-menthol at 30C. The oil phase of the reaction mixture was fractionated into an L-menthyl ester fraction (9c,11t-CLA rich) and an FFA fraction (10t,12c-CLA rich) by distillation. The FFA fraction was esterified again with an equimolar amount of L-menthol to enrich 10t,12c-CLA. The 10t,12c-CLA preparation was obtained as the resulting FFA fraction by distillation. 10t,12c-CLA was enriched to 91 percent with 40 percent recovery. To enrich 9c,11t-CLA, the L-menthyl ester fraction in the first esterification was chemically hydrolyzed, and the resulting FFA were esterified again with an equimolar amount of L-menthol. The 9c,11t-CLA preparation was obtained by chemical hydrolysis of the resulting L-menthyl ester fraction, followed by n-hexane extraction. 9c,11t-CLA was enriched to 94 percent with 42 percent recovery. This effective process for purification of CLA isomers using L-menthol is applicable to the production of food supplements.