不同糊化度籼米淀粉的结构及理化性质研究

本研究制备出糊化度分别为58%、80%、100%的籼米淀粉,探讨了糊化程度不同对籼米淀粉微观形貌、结晶特性、短程有序结构、层状结构及其热特性、黏度性质的影响。结构特性表明,随着糊化度的增加,籼米淀粉颗粒结构破坏程度加剧,双螺旋结构和分子有序排列被逐渐破坏,半结晶结构逐渐消失。热特性结果进一步证实,淀粉微晶结构随糊化度增加被破坏的程度加大,且不稳定的微晶优先被熔化使得剩余微晶的均匀性和稳定性有所提高。黏度性质表明,完全糊化籼米淀粉能在较低温度下吸水溶胀形成高黏度的溶液,但热糊稳定性差。尚余微晶结构的淀粉随糊化度的增加表现出更高的峰值黏度和更弱的热糊稳定性。

Structure and Physicochemical Properties of Indica Rice Starch with Different Degrees of Gelatinization

In this paper, indica rice starches with the gelatinization degree of 58%, 80% and 100% were prepared, and the effects of different gelatinization degree on the microstructure, crystallization properties, short-range ordered structure, layered structure, thermal properties and viscosity characteristics of indica rice starch were explored. The results of structural characteristics showed that with the increase of the degree of gelatinization, the degree of damage to the granular structure of indica rice starch intensified, the double helix structure and the orderly arrangement of molecules were gradually destroyed, and the semi-crystalline structure gradually disappeared. The results of thermal characteristics further confirmed that the damage degree of starch microcrystalline structure increased with the increase of gelatinization degree, and the unstable microcrystalline was preferentially melted, which improved the uniformity and stability of the remaining microcrystalline. The results of viscosity properties showed that the fully gelatinized indica rice starch could swell with water at low temperature to form a solution with high viscosity, but the stability of hot paste was poor. With the increase of gelatinization degree, indica rice starch with residual microcrystalline structure showed higher peak viscosity and weaker thermal paste stability.