发芽对精白保胚米淀粉分子结构的影响

Effect of Germination on Molecular Structure of Starch from Polished Rice with Germ

目的:研究发芽对精白保胚米淀粉分子结构的影响。方法:采用扫描电子显微镜、高效液相色谱、X射线衍射仪及傅里叶红外光谱(FT-IR)分析精白保胚发芽米淀粉颗粒的表面结构、相对分子质量分布、结晶度和特征结构的变化。结果:精白保胚米发芽之后淀粉颗粒表面结构变化不明显,但淀粉的相对分子质量、结晶度降低;发芽后精白保胚米淀粉的红外透光率降低,O-H键、C-H键和C-O键的伸缩振动均增强。结论:发芽过程中直链淀粉和支链淀粉降解,使精白保胚米淀粉分子结构发生明显变化。

Objective： To explore the effect of germination on molecular structure of starch from polished rice with germ.Methods： Scanning electron microscope（SEM）,high performance liquid chromatography（HPLC）,X-ray diffractometer（XRD） and Fourier transform infrared spectroscopy（FT-IR） were used to analyze the changes in surface structure,relative molecular weight distribution,crystallinity and characteristic structure of starch granules from germinated and non-germinated rice.Results： Compared with non-germinated rice,the surface microstructure of starch granules from germinated rice did not exhibited a significant change,but their molecular weight,crystallinity and IR transmittance revealed an obvious decrease,and the stretching vibration of O-H,C-H and C-O bonds was enhanced.Conclusion： During the germination process,amylose and amylopectin are degraded,which results in an obvious change in molecular structure of starch from germinated polished rice with germ.