目的为了能够更加充分了解贝母属药用植物,通过各种分析方法对两种贝母--浙贝母和平贝母中所包含的淀粉的物理化学性质进行了研究.方法采用X射线衍射,扫描电子显微镜(SEM)以及热分析(TGA)的方法对两种贝母中淀粉的性质进行了比较.结果通过研究发现,两种贝母淀粉的晶体类型都为典型的B型,这与马铃薯淀粉的晶体类型是-致的.浙贝母和平贝母淀粉的结晶度分别为29.9%和20.1%,而马铃薯淀粉的结晶度为44.9%.从两种贝母淀粉的结晶度可以看出,平贝母淀粉中直链淀粉的量要高于浙贝母淀粉中直链淀粉的量.两种贝母淀粉的颗粒尺寸为5~40μm,而且他们都小于马铃薯淀粉的颗粒尺寸.两种贝母淀粉颗粒的形状是圆形的和椭圆形的.热稳定性表明由于植物来源的不同导致淀粉颗粒结构不同,从而热稳定性存在明显的差异.结论两种贝母淀粉由于来源不同,物理化学性质存在明显的差异.

Objective To fully understand the medicinal plants ofFritillaria L.,the physicochemical properties of starch in two species of Fritillaria L.,F.thunbergii andF.ussurensis.were investigated by means of various analytical methods. Methods The properties of starch in the two different species ofFritillaria L.were compared by X-ray diffraction,scann-ing electron microscope(SEM)and the-mogravimetric analysis(TGA).Results The crystal type of starch in the two species ofFri-tillaria L.was the characteristic B-type which was in consistent with that of potato starch.The degrees of crystallinity ofF. thunbergii starch and F.ussurensis starch were about 29.9%and 20.1%,respectively.However,the degree of crystallinity of the potato starch was 44.9%. From the crystallinity degree of the starch in two species ofFritillaria L.,it could be concluded that the content of amylose inF.ussurensis starch was higher than that inF.thunbergii starch.The granule size of the starch in two species of Fritillaria L.ranged from 5 to 40μm,which were all smaller than that of the potato.The starch granule in two species of Fritillaria L.was in cycloidal or elliptic-shape.It could be concluded that the thermal stability of the starch in two species of Fritillaria L.was different due to the different structures of different starch in various plants by TGA. Conclusion The physicochemical properties of starch in two different species ofFritillaria L.differ a lot due to their geographical origin.