应用脱枝酶提取大米蛋白质的研究

Application of Debranching Enzyme for the Extraction of Rice Protein

为了提高大米蛋白提取的效率及质量,将一种新型的淀粉水解酶-脱枝酶引入大米蛋白的酶法提取工艺中。使用高效体积排阻色谱(HPSEC)分析相对分子质量分布表明大米淀粉经脱枝酶作用后重均相对分子质量降低明显;同时氢谱核磁共振图谱显示脱枝酶可将大米淀粉的α-1,6-糖苷键彻底水解,为糖化酶的水解提供了良好条件。将脱枝酶与糖化酶协同作用于大米制糖后的液化米渣,最终可将大分子的糊精完全水解为水溶性的寡糖从而除去,较单独使用糖化酶总糖的去除率提高39.7%。所获得大米粗蛋白的总氮质量分数达到90.58%,纯度较传统酶法提取大为提高。

Debranching enzyme was used to enhance the extraction efficiency and product quality ofrice protein. A significant decrease in molecular weight was detected by HPSEC for rice starchdigested by debranching enzyme and the1H- NMR analysis proved that the enzyme completelyhydrolyzed α- 1,6- linkages, which facilitated the following function of glucoamylase. Debranchingenzyme together with α-amylase and glucoamylase could entirely hydrolyze the dextrin in liquefiedrice dreg after sugar processing into water soluble oligosaccharides, which increased the removal rateby 38.9% compared with the processing only through glucoamylase. The total nitrogen content of thecrude protein reached up to 90.58%, which was higher than that obtained by the traditional methods.