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.
出处
《食品科学》
EI
CAS
CSCD
北大核心
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)
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
purple rice
protein-polyphenol complexes
structural composition
molecular morphology
atomic force microscope
