Todero Larissa M, Bassi Jaquelinne J, Lage Flávia A P, Corradini Maria Carolina C, Barboza Jayne C S, Hirata Daniela B, Mendes Adriano A
Institute of Chemistry, Federal University of Alfenas, Alfenas, MG, 37130-000, Brazil.
Bioprocess Biosyst Eng. 2015 Aug;38(8):1601-13. doi: 10.1007/s00449-015-1402-y. Epub 2015 May 3.
Isoamyl butyrate (banana flavor) was synthesized by esterification reaction of isoamyl alcohol and butyric acid in heptane medium. Immobilized Thermomyces lanuginosus lipase (TLL) prepared via physical adsorption on mesoporous poly-methacrylate particles (PMA) was used as biocatalyst. The factors that affect the esterification reaction were optimized by response surface methodology (RSM). Under optimal experimental conditions, maximum ester conversion percentage of 96.1 and 73.6% was reached after 50 and 90 min, respectively, for esterification reaction performed at equimolar ratio alcohol:acid at 500 and 2000 mM of each substrate. Under these experimental conditions, the esterification reaction was not controlled by external and intra-particle mass transfer effects. The product (isoamyl butyrate) was confirmed by proton nuclear magnetic resonance ((1)H NMR) spectroscopy. Reusability tests showed that the biocatalyst retained around 96 and 31% of its initial activity after eight successive esterification cycles performed at 500 and 2000 mM, respectively. The application of the biocatalyst prepared showed to be a promising strategy to catalyze flavor ester synthesis in a non-aqueous medium.
以异戊醇和丁酸为原料，在庚烷介质中通过酯化反应合成了丁酸异戊酯（香蕉味香精）。采用物理吸附法将嗜热栖热放线菌脂肪酶（TLL）固定在介孔聚甲基丙烯酸酯颗粒（PMA）上，用作生物催化剂。采用响应面法（RSM）对影响酯化反应的因素进行了优化。在最佳实验条件下，当醇与酸的摩尔比为等摩尔比，每种底物浓度分别为500 mM和2000 mM时，酯化反应分别在50分钟和90分钟后达到最大酯转化率，分别为96.1%和73.6%。在这些实验条件下，酯化反应不受外部和颗粒内传质效应的控制。产物（丁酸异戊酯）通过质子核磁共振（¹H NMR）光谱进行了确认。重复使用性测试表明，在分别为500 mM和2000 mM的条件下连续进行八次酯化循环后，生物催化剂分别保留了其初始活性的约96%和31%。所制备的生物催化剂的应用显示出在非水介质中催化风味酯合成的一种有前景的策略。
