汽蒸处理对苦荞麦粉物化和结构特征的影响

Effects of steaming on physicochemical and structural properties of tartary buckwheat flour

该文研究了汽蒸处理和未处理苦荞粉的色度、糊化特性,通过偏光显微技术、X射线衍射技术和红外吸收光谱技术表征了淀粉和蛋白结构的变化规律,进而揭示了其特性变化的可能机制。结果表明:汽蒸处理引起苦荞粉的粒径大小略有增加;淀粉的结晶度及短程有序结构含量降低;蛋白质的部分α螺旋和β折叠结构转变为无规则卷曲结构;增加了苦荞粉的白度值和黄度值、降低了苦荞粉的亮度值和红度值;降低了苦荞粉的糊化黏度、低谷黏度、崩解值、最终黏度及回生值,而糊化温度升高。汽蒸处理引起苦荞粉中的淀粉发生部分胶凝化及蛋白质发生变性,改善了苦荞粉的色度特征及苦荞粉糊的稳定性。

This study investigated the effects of steaming on physicochemical properties and structure of tartary buckwheat flour.The color parameters and pasting properties of tartary buckwheat flour before and after steaming were measured,and mechanisms of changes in starches and protein structures were also revealed.The results showed that steaming increased the particle size of the flour slightly,while starches had decreased crystallinity and short-range ordered structure.Moreover,someα-helix andβ-sheet conformations of proteins in the flour transformed to random coils.Furthermore,steaming decreased the brightness and redness values of the flour,while the whiteness and yellowness values increased.In addition,steaming decreased the peak viscosity,trough viscosity,breakdown viscosity,final viscosity,and setback viscosity of the flour,while the pasting temperature increased.In conclusion,steaming partially gelatinized starches and deformed proteins in tartary buckwheat flour,which improved the color of the flour as well as the stability of the paste.