Synthesis of structured triacylglycerols by lipase-catalyzed acidolysis ina packed bed bioreactor

Structured triacylglycerols (ST) from canola oil were produced by enzymatic acidolysis in a packed bed bioreactor. A commercially immobilized 1,3-spec ific lipase, Lipozyme IM, from Rhizomucor miehei, was the biocatalyst and c aprylic acid the acyl donor. Parameters such as substrate flow rate, substr ate molar ratio, reaction temperature, and substrate water content were exa mined. Highperformance liquid chromatography was used to monitor the reacti on and product yields. The study showed that all of the parameters had effe cts on the yields of the expected di-incorporated (dicaprylic) ST products. Flow rates below 1 mL/min led to reaction equilibrium, and lower flow rate s did not raise the incorporation of caprylic acid and the product yield. I ncorporation of caprylic acid and the targeted di-incorporated ST was incre ased by similar to 20% with temperature increase from 40 to 70 degrees C. I ncreasing the substrate molar ratio from 1:1 to 7:1 increased the incorpora tion of caprylic acid and the product yield slightly. Water content in the substrate also had a mild influence on the reaction. Water content at 0.08% added to the substrate gave the lowest incorporation and product yield. Th e use of solvent in the medium was also studied, and results demonstrated t hat it did not increase the reaction rate at 55 degrees C when 33% hexane ( v/v) was added. The main fatty acids at the sn-2 position of the ST were C- 18:1, 54.7 mol %; C-18:2, 30.7 mol %; and C-18:3, 11.0 mol %.