Lipase-catalyzed production of structured lipids via acidolysis of fish oil with caprylic acid

Structured lipids containing eicosapentaenoic and docosahexaenoic acids wer e manufactured in a batch reactor by lipase-catalyzed acidolysis of fish oi l with caprylic acid. The following free lipases (Lipase AP, Aspergillus ni ger; Lipase P, Pseudomonus sp.; Lipase AY, Candida rugosa; Lipase AK, Pseud omonas fluoresescens; Lipase F, Rhizopus oryzae; Lipase D, Rhizopus delemar ) were screened under selected reaction conditions. The conditions were enz yme load 5%, substrate mole ratio 1:6 (fish oil: caprylic acid), and reacti on temperature of 50C. Lipase AK had the highest activity and was suitable for production of structured lipids from fish oil. The optimal mole substra te ratio of fish oil to caprylic acid for Lipase AK was 1:6 to 1:8. The lim e course of the reaction at different enzyme loads demonstrated that 40% in corporation of caprylic acid could be obtained for Lipase AK in 5 h with 10 % enzyme load. Addition of water had little effect on the activity of the l ipase. Lipase AK and Lipozyme IM were further compared under the same condi tions, in which Lipase AK had a slightly higher incorporation of caprylic a cid, similar acyl migration of caprylic acid from sn-1,3 positions to the s n-2 position, and a slightly lower selectivity towards docosahexaenoic acid .