紫米蛋白-多酚复合物的结构组成及分子形貌  

Structural Composition and Molecular Morphology of Purple Rice Protein-Polyphenol Complexes

作　　者：梁征[1] 熊思慧 郭莹[1] 刘刚[1] 黄庆荣[1] 何静仁[1] 

机构地区：[1]武汉轻工大学食品科学与工程学院,湖北武汉430023

出　　处：《食品科学》2016年第21期85-90,共6页Food Science

基　　金：湖北省自然科学基金项目(2014CFB891);湖北省科技支撑计划项目(2015BHE015;2015BBA167);武汉市青年科技晨光计划项目(2014072704011258)

摘　　要：为研究紫米中蛋白-多酚复合物的分离纯化及其结构组成与分子形貌,采取Osborne分级提取从紫米中得到紫米蛋白-多酚复合物,采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析其分子质量,邻苯二甲醛柱后衍生法分析比较紫米蛋白-多酚复合物以及大米蛋白的氨基酸组成,高效液相色谱-二极管阵列检测器-质谱联用技术分析鉴定紫米蛋白-多酚复合物中花色苷聚合物的基本单体组成,并利用原子力显微镜观察紫米蛋白-多酚复合物的表面形貌特征。结果表明,紫米蛋白-多酚复合物的蛋白质质量分数为(94.3±2.7)%,多酚含量为(10.1±4.0)mg/g;紫米蛋白-多酚复合物与大米蛋白在37 ku以上分子质量处亚基组成存在明显差异;复合物的氨基酸组成更加丰富,有更优的必需氨基酸组成;复合物中花色苷单体组成为矢车菊素-3-O-葡萄糖苷和芍药素-3-O-葡萄糖苷;紫米蛋白-多酚复合物以不规则球形结构为主,其结合单元的粒径大约为4.7 nm左右。本实验对后续探索有色谷物多酚复合物的功能特性、多酚-蛋白质相互作用与生物活性等提供了科学依据。The present study investigated the separation and purification of purple rice protein-polyphenol complexes as well as their structural composition and molecular morphology.Purple rice protein-polyphenol complexes were separated from purple rice by Osborne sequential extraction.It was found that the purity of purple rice protein was（94.3 ± 2.7）%,and the content of polyphenol was（10.1 ± 4.0） mg/g.Sodium dodecyl sulfate polyacrylamide gel electrophoresis results indicated that purple rice protein-polyphenol complexes were significantly different from rice glutenin in terms of subunits with molecular weight over 37 ku.The amino acid composition of protein-polyphenol complexes was richer than that of rice glutenin as analyzed by post-column derivatization with ortho phthalaldehyde,with superiority observed in essential amino acid composition according to the FAO/WHO model.The monomeric anthocyanins in purple rice protein-polyphenol complexes,identified by high performance liquid chromatography with diode array detector-mass spectrum,was cynidin-3-O-glucoside and paeonidin-3-O-glucoside.Atomic force microscope showed that the surface topography of purple rice protein-polyphenol complexes was irregularly spherical with particle size of 4.7 nm.This study can provide the scientific basis for further studies on functional and biological characteristics of colored rice.

关 键 词：紫米 蛋白-多酚复合物 结构组成 分子形貌 原子力显微镜 

分 类 号：Q946.1[生物学—植物学]