糯小麦淀粉形态及内部结构的研究

Morphological features and internal structure of waxy wheat starch

利用偏光显微镜、扫描电镜和X射线衍射仪和激光共聚焦显微镜对糯小麦淀粉和普通小麦淀粉的颗粒形貌、结晶性质和内部结构进行了对比研究和分析。结果表明:糯小麦淀粉和普通小麦在颗粒形貌、颗粒大小分布、结晶结构和内部结构方面具有相似的性质。与普通小麦淀粉相比,糯小麦淀粉颗粒表面不平滑,存在较多凹坑,且能够观察到明显的微孔;两种小麦淀粉A型颗粒直径基本相同,但糯小麦淀粉B型颗粒直径小于普通小麦淀粉;糯小麦淀粉和普通小麦淀粉均呈现典型的A型结晶特征,但糯小麦淀粉的相对结晶度高于普通小麦淀粉;两种淀粉均呈现生长环结构,直链淀粉主要集中在颗粒中心部位。

Morphological features,crystalline properties and internal structure of waxy wheat starch were compared with those of normal wheat starch using polarization microscope, scanning electron microscopy （SEM）, X ray diffraction（XRD） and confocal laser scanning microscope （CLSM）.The morphologies, granule populations, crystalline properties and internal structure were found to be similar with the two starches.However,the surface of waxy wheat starch granules was not smooth, more holes were observed on the surface.A-type starch granules were basically the same, however, waxy wheat starch contained a smaller proportion of B-type granules. XRD results shows that both starches exhibit A type crystalline structure and waxy wheat starch had higher degree of crystallinity than normal wheat starch.Growth ring structures can be clearly identified by CLSM and amylose mainly concentrated in particles near the center.