紫薯淀粉结构与理化性质研究

Structure and physicochemical features of starch from purple potato

中文关键词:  紫薯淀粉  结构  理化性质

英文关键词:purple potato starch  structure  physicochemical features

中文摘要:

      目的 了解紫薯淀粉的结构和理化性质。方法 利用碱提取法从紫薯中提取淀粉, 与普通玉米淀粉进行对比, 分别对淀粉结构(分子链结构、结晶结构等)和理化性质(透明度、凝沉性、冻融稳定性、热稳定性)进行研究。结果 紫薯淀粉直链含量(24.5%)比玉米淀粉(26.7%)低, 两者均为A型结晶结构, 但紫薯淀粉的结晶度和分子有序程度比玉米淀粉高; 紫薯淀粉糊的透明度高于玉米淀粉糊, 且随时间延长其透明度下降程度比玉米淀粉糊低; 紫薯淀粉糊不易发生凝沉现象, 但其析水率(21.4%)比玉米淀粉糊高, 即冻融稳定性弱于玉米淀粉糊; 此外, 紫薯淀粉部分结构的热稳定性大于玉米淀粉。结论 紫薯淀粉在分子链结构和结晶结构上与玉米淀粉有较小差异, 但在理化性质上与玉米淀粉差别较大, 可为其工业应用提供指导基础。

英文摘要:

      Objective To study the structure and physicochemical properties of purple potato starch. Methods Purple potato starch was extracted by alkali extraction method. With the comparation of common maize starch, the structure (molecular chain structure, crystalline structure) and physicochemical features (transparency, retrogradation, freeze-thaw stability and thermal stability) of starch were determined. Results The amylose content of purple potato starch (24.5%) was lower than that of maize starch (26.7%). Both starches showed A-type crystalline structure, but the relative crystallinity and short-range orders of purple potato starch was higher. The transparency of purple potato starch paste was higher than that of corn starch paste, and its transparency decreased with time to be lower than corn starch paste. The purple potato starch paste was not easy to be coagulated, but its water precipitation rate (21.4%) was higher than that of corn starch paste, which indicated that the freeze-thaw stability was weaker than corn starch paste. And purple potato starch had better thermal stability than maize starch. Conclusion The purple potato starch has a small difference in molecular chain structure and crystal structure from corn starch, but it has a large difference in physical and chemical properties from corn starch, which can provide a guiding basis for its industrial application.