Production of Structured Lipids by Enzymatic Incorporation of Caprylic Acid Into Soybean Oil

A MLM-type structured lipid was produced using lipase-catalyzed acidolysis of soybean oil and caprylic acid. An immobilized sn-1,3 specific lipase, Lipozyme TL IM from Thermomyces lanuginosus, was used as the biocatalyst in this study. Acidolysis reactions were carried in free-solvent system and the products were analyzed by gas chromatography. Mol% of caprylic acid incorporation into soybean oil was affected by enzyme load, substrate molar ratio, water added, reaction time and reaction temperature. The optimum reaction conditions were enzyme load 16% based on weight of reactants, molar ratio of caprylic acid to soybean oil 4:1, water added 4% based on enzyme load, 40t and 150 rpm for 20h according to orthogonal experimental results. Under these conditions, a SL containing 27.01% C8:0, 6.71% C16:0, 3.48% C18:0, 19.46% C18:l, 40.49% C18:2 and 2.85% C18:3 was obtained. The C8:0 incorporation decreased by 30% when the immobilized lipase was used after 10 cycles.