Structured Lipids Produced through Lipase-Catalyzed Acidolysis of Canola Oil

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Enzymatic acidolysis of canola oil through caprylic acid was investigated to produce certain medium chain Ttriacyliglycerol (TAG) structured lipids (SLs). Lipozyme TL IM, an sn-1,3 specific Thermomyces lanuginosa lipase, and Novozym 435, a non-specific Candida antarctica lipase, were utilized as the biocatalysts in a batch reactor. Reaction conditions were designed according to Taguchi’s approach, considering three levels of fatty acid to oil ratio (1:1, 2:1, and 3:1), three levels of enzyme load (4, 8 and 12%, w/w), three levels of temperature (45, 55, and 65°C) as well as three levels of reaction time (15, 30 and 45 hours). Results indicated that fatty acid composition of canola oil was modified by the above acidolysis reactions. The highest mole percent of caprylic acid incorporation (37.2 mole%) was obtained after 15 hours of incubation in the presence of Lipozyme TL IM at 55°C, fatty acid to oil ratio of 3:1 and at 12% of enzyme level. However, with Novozym 435 the highest level of incorporation (38.5 mole%) was obtained after 45 hours of reaction at 45°C, fatty acid to oil ratio of 3:1, and at 8% enzyme level. Novozym 435 was able to incorporate more caprylic acid in the oil than did Lipozyme TL IM. SLs prepared using either Lipozyme TL IM or Novozym 435 differed in terms of their TAG compositions. According to the obtained results, SLs produced by use of Lipozyme TL IM lipase contained higher levels of MLM-type (Medium-Long-Medium) triacylglycerols than those produced using Novozym 435 lipase (21.2 and 9.9%, respectively).