响应曲面优化葡甘露聚糖超声法磷酸酯化改性研究  

Response surface methodology for optimizing phosphate esterification of glucomannan by ultrasound methodology

作　　者：李小菊[1] 李治军 李惠成[1] 武芸[1] 张宾 仲超 刘维涛 LI Xiao-ju;LI Zhi-jun;LI Hui-cheng;WU Yun;ZHANG Bing;ZHONG Chao;LIU Wei-tao(College of Chemistry and Chemical Engineering,Longdong University,Xifeng 745000)

机构地区：[1]陇东学院化学化工学院

出　　处：《中国食品添加剂》2019年第12期112-124,共13页China Food Additives

基　　金：青年科学基金项目《柔性共价有机框架的构建及其动态响应行为研究》（201702089）;甘肃省应用化学省级重点学科建设项目（GSACKS20130113);Supported by the Key Constructive Disciplines of Longdong University(LDXYKCD201704）;陇东学院博士科研启动资金资助项目《天然高分子材料的研究与应用》（XYBY1409）

摘　　要：目的:六偏磷酸钠作为改性剂对葡甘露聚糖进行了磷酸酯化的改性,来增加葡甘露聚糖的稳定性。方法:通过响应曲面法建立了超声辅助合成酯化魔芋葡甘露聚糖的二次多项数学模型。通过二次回归设计得到了酯化魔芋葡甘露聚糖的取代度与质量比、pH、反应时间、反应温度的回归模型。通过红外,扫描电镜,流变性考察酯化魔芋葡甘露聚糖的结构和性质。结果:该模型可以预测酯化魔芋葡甘露聚糖的取代度,并且克服了正交设计实验中存在的各因素不能在整个取值区域内进行组合的缺点。最佳酯化工艺条件为:六偏磷酸钠与葡甘露聚糖质量比为1∶6.77,pH为2.57,反应时间t为1.14h,反应温度T为54.4℃。酯化魔芋葡甘露聚糖取代度实测为1.91%,与理论计算取代度1.87%接近。通过红外验证,将磷酸基团引入葡甘露聚糖主链分子上获得了酯化魔芋葡甘露聚糖;扫描电镜进一步显示,酯化魔芋葡甘露聚糖的结构比未改性的葡甘露聚糖更紧密;流变性实验表明,酯化魔芋葡甘露聚糖在稳定性,抗菌性方面均为最优。Objective : Phosphate esterification was performed to improve the stability of glucomannan by using Sodium hexametaphosphate as a modifier. Methods: A quadratic polynomial mathematical model of ultrasonic-assisted synthesis of esterified konjac glucomannan was established by response surface methodology. The regression models of substitution degree and mass ratio, pH, reaction time and reaction temperature of esterified konjac glucomannan were obtained by quadratic regression design. The structure and properties of esterified konjac glucomannan were investigated by infrared, scanning electron microscopy and rheological properties. Results : The model can predict the degree of substitution of esterified konjac glucomannan, and is better than orthogonal design experiment which not all factors can be combined into consideration at whole experiment range. The optimum esterification conditions were: the mass ratio of glucomannan to sodium hexametaphosphate 1 ∶ 6.77, pH 2.57, reaction time 1.14 h, and reaction temperature 54.4℃. Under the above conditions, the actual substitution degree of esterified konjac glucomannan was 1.91%, which was close to the prediction of 1.87% by the model. Infrared detection verified that esterified phosphoric acid was added into the main chain of glucomannan to form konjac glucomannan. Scanning electron microscopy further showed that the structure of esterified konjac glucomannan was denser than unmodified konjac glucomannan. Rheological properties experiments showed that esterified konjac glucomannan had the best stability and antimicrobial activity.

关 键 词：葡甘露聚糖 超声 酯化改性 六偏磷酸钠 响应曲面 

分 类 号：O636.1[理学—高分子化学] TQ649.44[理学—化学]