乌冬面专用变性淀粉及其结构表征

采用交联―酯化―预糊化复合变性制备乌冬面专用改性淀粉,并与木薯原淀粉、交联淀粉及交联―酯化淀粉进行比较。结果表明,交联淀粉偏光显微及颗粒形貌没发生明显变化,交联变性并未破坏淀粉结晶结构;交联―酯化淀粉颗粒出现粘连和聚集现象,部分颗粒表面出现凹陷和裂纹现象;红外光谱表明,交联―酯化―预糊化复合变性淀粉在1 728 cm–1、1 247 cm–1附近出现新的吸收峰,分子内引入乙酰基团,X–射线衍射光谱显示,交联―酯化―预糊化复合变性淀粉在5.6°和22°处衍射峰强度减弱,A型特征峰加强,结晶类型由"C"型向"A"型转变;交联―酯化淀粉经预糊化处理后,淀粉颗粒膨胀破裂,结晶结构受到彻底破坏,淀粉偏光十字消失,但预糊化处理未破坏淀粉分子化学键。

Preparation and characterization of modified starch for Udon noodles

Three kinds of modified starch for Udon noodles were studied in this paper.And a comparison of characterization and properties of native cassava,crosslinked starch,and crosslinked–esterified starch was investigated.The results showed that:there was little change in the polarized microscopic and morphological properties of crosslinked starch,and its crystal structure remained in good shape,while the crosslinked–esterified starch turned to sticky and gathered together,and hollows and cracks formed on the surface of some of the particles.The crosslinked–esterified starch showed new absorption peak at 1?728cm–1 and 1?247cm–1,which assigned to the introduction of acetyl groups in the starch molecular,the diffraction peak intensity of crosslinked–esterified starch weakened at 5.6°and 22°according to the X–ray diffraction spectrum,the A–type characteristic peak intensified,and the crystal type went from C–type to A–type.After the pregelatinization of the crosslinked–esterified starch,its particles swelled up and fractured,crystal structure of them were damaged completely,and the polarized microscopic cross disappeared,while the connection of different groups inside the starch molecular remained undamaged.