利用扫描电镜技术(SEM)研究糯小麦与非糯小麦籽粒微观结构的差异以及糯小麦粉配粉对面食品微观结构的影响,以探讨糯小麦粉对面食品品质影响的原因。结果表明:糯小麦籽粒中淀粉与蛋白结合状态受品种硬度的影响,仅从SEM照片上无法分辨出淀粉颗粒大小分布的差异;非糯小麦糊化后的凝胶内部结构坚实,糯小麦则结构疏松多孔、呈现均匀的网状结构且孔壁薄而透亮;随着糯小麦粉配比的增加,凝胶逐渐变得疏散、蓬松、多孔,且所形成的空隙壁也呈现逐渐变薄、均匀透亮的蜂窝状。糯小麦面团蛋白质基质不连续,薄而透亮呈鳞片状,且与淀粉结合松散,非糯小麦面团网络坚实、结构连续,且与淀粉颗粒紧密结合;糯小麦粉的添加使得配粉面团面筋逐渐弱化、不连续,结构逐渐疏散。
To investigate the mechanism of the effect of waxy flour blending to wheat-based product quality,the microstructures of wheat kernel,RVA gel and developed dough of waxy wheat,non-waxy wheat and their blends were studied with scanning electron microscope(SEM) technology.Results:The microstructure of a wheat kernel depends on kernel hardness and there is no obvious difference observed from the SEM photos between a waxy wheat kernel and a non-waxy wheat kernel.The internal structure of RVA gel of non-waxy wheat flour is firm while that of waxy flour is soft,spongy and netlike with very thin and transparent cells.With blending of waxy flour,the microstructure of RVA gel turns to be floppy and lacunaris and the cell wall becomes thinner.The protein matrix of developed dough of waxy wheat is discontiguous,thin,bright and scalelike with loose connection of starch granules,while that of non-waxy wheat is very firm and contiguous and combined with starch granules very tightly.The blending of waxy flour results in a weaker and more incompact structure of dough.