Carbohydrate Laboratory, College of Light Industry and Food Science, South China University of Technology , Guangzhou 510640, China.
J Agric Food Chem. 2013 Oct 16;61(41):9882-91. doi: 10.1021/jf401467u. Epub 2013 Oct 7.
Enzymatic esterification of starch with long-chain fatty acid was investigated by using ionic liquids 1-butyl-3-methylimidazolium choride ([BMIm]Cl) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) as reaction media. An industrial lipase produced by Candida rugosa was used to modify starch with lauric acid. The effect of reaction parameters such as the lipase dosage, the molar ratio of lauric acid/anhydroglucose unit (AGU) in starch, and the reaction temperature as well as the reaction time on the degree of substitution (DS) of long-chain fatty acid starch esters was studied. The maximum DS value was 0.171 under the given conditions. The maximum solubility of high-amylose starch measured by turbidity was 11.0/100 g of [BMIm]Cl. The esterification products were confirmed according to Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) analysis. The morphological and crystallographic properties of native starch were largely disrupted during modification process as indicated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) data. The thermal stability of the starch laurates was found to decrease compared to native starch. After reaction, the ionic liquid was effectively recycled and reused. This paper explores the potential of ionic liquids as solvent for the enzymatic synthesis of long-chain fatty acid starch esters.
采用离子液体 1-丁基-3-甲基咪唑氯([BMIm]Cl)和 1-丁基-3-甲基咪唑四氟硼酸盐([BMIm][BF4])作为反应介质，研究了长链脂肪酸与淀粉的酶酯化反应。使用由 Candida rugosa 产生的工业脂肪酶对淀粉进行改性，用月桂酸进行修饰。研究了反应参数（如脂肪酶用量、淀粉中天冬酰胺葡萄糖单元（AGU）与月桂酸的摩尔比、反应温度和反应时间）对长链脂肪酸淀粉酯取代度（DS）的影响。在给定条件下，DS 值的最大值为 0.171。通过浊度法测量高直链淀粉的最大溶解度为 11.0/100 g [BMIm]Cl。根据傅里叶变换红外（FT-IR）和核磁共振（NMR）分析确认了酯化产物。扫描电子显微镜（SEM）和 X 射线衍射（XRD）数据表明，在改性过程中，天然淀粉的形态和结晶性能发生了很大的破坏。与天然淀粉相比，淀粉月桂酸酯的热稳定性有所降低。反应后，离子液体得到了有效回收和再利用。本文探讨了离子液体作为溶剂在酶法合成长链脂肪酸淀粉酯中的应用潜力。
