Structured Lipids Produced through Lipase-Catalyzed Acidolysis of Canola Oil

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-۱,۳ specific Thermomyces lanuginosa lipase, and Novozym ۴۳۵, 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 (۱:۱, ۲:۱, and ۳:۱), three levels of enzyme load (۴, ۸ and ۱۲%, w/w), three levels of temperature (۴۵, ۵۵, and ۶۵°C) as well as three levels of reaction time (۱۵, ۳۰ and ۴۵ 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 (۳۷.۲ mole%) was obtained after ۱۵ hours of incubation in the presence of Lipozyme TL IM at ۵۵°C, fatty acid to oil ratio of ۳:۱ and at ۱۲% of enzyme level. However, with Novozym ۴۳۵ the highest level of incorporation (۳۸.۵ mole%) was obtained after ۴۵ hours of reaction at ۴۵°C, fatty acid to oil ratio of ۳:۱, and at ۸% enzyme level. Novozym ۴۳۵ was able to incorporate more caprylic acid in the oil than did Lipozyme TL IM. SLs prepared using either Lipozyme TL IM or Novozym ۴۳۵ 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 ۴۳۵ lipase (۲۱.۲ and ۹.۹%, respectively).