Department of Food Engineering, Inonu University, 44280 Malatya, Turkey.
J Agric Food Chem. 2009 Nov 11;57(21):10466-70. doi: 10.1021/jf902816e.
With the aim of determining the fatty acid (FA) selectivity of lipases, a mixture of oleic acid and monoacid triacylglycerols (TAGs) including tricaproin (T6), tricaprylin (T8), tricaprin (T10), trilaurin (T12), trimyristin (T14), tripalmitin (T16) and tristearin (T18) was used as the substrate in acidolysis performed in hexane. Three immobilized lipases, namely, Lipozyme TL IM from Thermomyces lanoginosus, Lipozyme RM IM from Rhizomucor miehei and Novozym 435 from Candida antarctica, were used as biocatalyst. The effects of operating variables including the mole ratio of oleic acid to monoacid TAG, temperature, enzyme dosage and reaction time on incorporation were also investigated. Significantly different incorporation rates were obtained for different TAGs used (P < 0.05). Incorporation of oleic acid into TAGs except tricaproin and tricaprylin was higher for all the TAGs with Lipozyme TL IM catalyzed reactions than those of other two enzymes tested. Incorporation of oleic acid decreased as the acyl chain length of FA in the TAG increased with Novozyme 435 catalyzed acidolysis. Compared to the other substrate mixtures, the highest incorporation was observed for oleic acid and tricaproin mixture with three lipases tested. It was shown that the FA selectivity of the lipases is strongly dependent on the acyl chain length of FA in a TAG.
为了确定脂肪酶对脂肪酸（FA）的选择性，使用油酸和单酸三酰基甘油（TAG）的混合物（包括三辛酸甘油酯（T6）、三辛酸甘油酯（T8）、三辛酸甘油酯（T10）、三辛酸甘油酯（T12）、三肉豆蔻酸甘油酯（T14）、三棕榈酸甘油酯（T16）和三硬脂酸甘油酯（T18））作为在正己烷中进行酸解的底物。使用了三种固定化脂肪酶，即来自Thermomyces lanoginosus 的 Lipozyme TL IM、来自 Rhizomucor miehei 的 Lipozyme RM IM 和来自 Candida antarctica 的 Novozym 435，作为生物催化剂。还研究了操作变量（包括油酸与单酸 TAG 的摩尔比、温度、酶剂量和反应时间）对结合的影响。不同 TAG 得到的结合率有显著差异（P<0.05）。用 Lipozyme TL IM 催化的反应中，除三辛酸甘油酯和三辛酸甘油酯外，油酸与所有其他 TAG 的结合率均高于测试的其他两种酶。随着 TAG 中 FA 的酰基链长的增加，Novozyme 435 催化的酸解中油酸的结合率降低。与其他底物混合物相比，在三种测试的脂肪酶中，油酸和三辛酸甘油酯混合物的结合率最高。结果表明，脂肪酶对 FA 的选择性强烈依赖于 TAG 中 FA 的酰基链长。
