激光共聚焦显微拉曼光谱法测定籼米淀粉回生

The Retrogradation of Long-shaped Rice Starch Determined by Using Laser Confocal Microraman Spectrometry

目的和方法:本文研究利用激光共聚焦显微拉曼(Laser Confocal Micro-Raman,LCM-Raman)分子振动光谱快速检测籼米淀粉回生的可能性;结果:拉曼光谱中一些振动模式(包括1122.37cm-1处的C-O伸缩和C-O-H弯曲振动,1082.83cm-1的C-O-H弯曲振动,1050.05cm-1的C-C伸缩振动,854.31cm-1的C-H变形振动和440.66cm-1处的吡喃环骨架振动)的相对强度均随淀粉回生程度的增加呈现降低的规律。将这些拉曼峰的相对强度倒数与DSC回生焓值进行相关性分析发现,854.31cm-1、1082.83cm-1和1050.05cm-1这些峰的相关系数均能在0.9以上。结论:这3个振动模式的相对强度变化可作为定量指示籼米淀粉回生程度的多重指标。

The possibility of laser confocal micro-raman （LCM-Raman） spectroscopy for rapid analyzing the retrogra- dation of long -shaped rice starch was investigated. The results showed that the relative intensity of some vibrational modes reduced regularly with increased extent of the retrogradation. These peaks included C-O stretching and C -O -H bending （1 122.37 cm -1 ）, C-O-H bending （1 082.83 cm -1 ）, C-C stretching （1 050.05 cm -1 ）, C-H deformation （854.31 cm -1 ）, and skeletal modes of pyranose ring（440.66 cm -1 ）. By the correlation analysis between retrogradation enthalpy of DSC and the relative intensity reciprocal of above vibrational modes, these LCM-Raman peaks at 854.31 cm -1 , 1 082.83 cm -1 , and 1 050.05 cm -1 had correlation coefficient above 0.9. Therefore, the relative intensity change of the three vibrational modes listed above can be as multi-index to quantify the degree of the retrogradation.