【摘要】 以三聚磷酸钠为酯化剂,干法制备了高取代度木薯淀粉磷酸酯(CSP-HDS),研究了产品理化特性和结构表征。结果表明,取代度为0.073的产物表观粘度最大为2.656 Pa.s;取代度为0.055的产物糊透明度最高,透光率为85.6%;取代度为0.073的产物冻融稳定性最好,糊液经5次冻融无水析出。与木薯淀粉相比,酯化反应后产物粘度增大,糊化温度降低、糊化时间缩短、取代度高于0.064的产品冷水可溶,糊透明度、冻融稳定性得到改善。FTIR分析发现,1 016 cm-1的吸收峰强度加强,证实在淀粉中引入了磷酸根基团;XRD分析表明,酯化反应主要发生在淀粉分子非晶区,在结晶区也有一定程度的反应;淀粉-碘复合物吸收光谱分析表明,淀粉磷酸酯糊液对碘的吸光度降低,说明淀粉部分分子螺旋结构被破坏。更多还原

【Abstract】 The cassawa starch phosphate monoesters with a high degree of substitution（CSPHDS） were（prepared） via the dry process with sodium tripolyphosphate（STP） as esterifying agent.The physicochemical properties of CSP-HDS were investigated and the structures were characterized.CSP-HDS with a DS of 0.073 had a maximum apparent viscosity of 2.656 Pa·s,CSP-HDS with a DS of 0.055 had the highest transparency of 85.6%,and CSP-HDS with a DS of 0.073 had the best stability of freeze-thaw and no water was separated from the gel after freeze-thaw for 5 times.Compared with native starch,CSP-HDS shows higher viscosity,its gelation temperature is lower and gelation time is shorter.CSP-HDS with DS>0.064 dissolves in water at room temperature,its paste transparency and freeze-thaw stability are improved.The FTIR results show that the peak at 1 016 cm^-1 is enhanced,indicating the group of phosphate has been induced in starch molecule.The XRD results indicate that the esterification of starch mainly occurs in the amorphous region and less in the crystalline region.The absorbency of the starch-iodine composite is decreased,indicating that the helix（structure） of cassawa starch has been partly destroyed.更多还原