超微粉碎对木薯淀粉老化特性的影响

Effects of superfine grinding on retrogradation properties of tapioca starch

本文以扫描电子显微镜(SEM)、直链以及支链淀粉含量、快速粘度分析仪(RVA),凝沉性、冻融稳定性及碘结合能力为分析手段,研究木薯淀粉经过不同时间(0、15、30、45、60 min)超微粉碎处理后的老化特性变化。结果表明:经过不同时间超微粉碎处理后,木薯淀粉表面结构破坏,颗粒团聚,直链淀粉含量增加,支链淀粉含量降低;木薯淀粉糊液回复值显著降低,且处理时间超过30 min后,下降趋势变缓,这说明不同时间超微粉碎处理对淀粉的短期老化有抑制作用。然而,随着超微粉碎处理时间的增加,木薯淀粉冻融稳定性降低、凝沉性增加、碘结合能力增强,这表明超微粉碎处理对木薯淀粉的长期老化有一定的促进作用。

In this study,methods of scanning electron microscope （ SEM ） , the content of the amylose and amylopectin, rapid viscosity analyzer（ RVA）, coagulation, freeze-thaw stability and iodine binding ability were used to investigate the changes of retrogradation properties of tapioca starch after treated by superfine grinding with different treating time （0,15,30,45,60 rain）. The results demonstrated that the surface structure of tapioca starch was destoryed and particles aggregated, amylose content increased,amylopectin content decreased.The setback of tapioca starch paste was significantly reduced after superfine grinding treatment with different treating time, and when the treating time beyond 30 min, the change was not obvious. This result indicated that superfine grinding treatment with different treating time inhibited the short-term retrogradation of tapioca starch. However,the freeze-thaw stability of tapioca starch after superfine grinding treatment decreased, and the coagulation and the iodine binding capacity enhanced, which revealed that superfine grinding treatment partly contributed to the long- term retrogradation of tapioca starch.