马铃薯交联淀粉的制备与结构表征

以三偏磷酸钠为交联剂,水分散法制备了马铃薯交联淀粉,应用红外光谱、X射线衍射、扫描电镜和偏光显微镜等分析测试方法,观察和研究了不同取代度马铃薯交联淀粉的颗粒形貌及其结晶结构。结果表明,产物取代度随交联反应时间的延长而增大;交联反应主要发生在淀粉分子的无定形区,在结晶区也有一定程度的反应;随着取代度的增大,淀粉中受侵蚀的颗粒增多,颗粒表面的小凹痕数量明显增加,部分颗粒表面变粗糙,颗粒内部出现凹陷甚至爆裂;交联淀粉的偏光十字清晰易见;1 017.08cm-1的吸收峰强度加强,证实在淀粉中引入了磷酸根基团。

Preparation and Structure Characterization of Crosslinked Potato Starch

The crosslinked potato starch(CPS) was prepared via the water dispersion process with sodium trimetaphosphate(STP) as crosslinking agent.The granule appearance and crystal structure of CPS were studied at different degree of substitution(DS) with infra-red spectrum(FTIR),scanning electron microscopy(SEM),X-ray diffraction(XRD) and polarizing microscopy(PLM).Results indicate that DS increases as the reaction time prolongating,and the polarization cross is obviously observed in CPS granules.The XRD indicates that the crosslink reaction of starch mainly occurs in the amorphous region and less in the crystalline region.The SEM shows that there are a certain of dent and splits on the granule surface with the increase of DS.The FTIR shows that the peak at 1 017.08cm-1 is enhanced,indicating the groups of phosphate have been introduced in the starch molecules.