青稞和小麦醇溶蛋白和谷蛋白结构性质的比较研究  

Comparison of Structure Characteristics of Gliadin and Glutenin in Highland Barley and Wheat

作　　者：王洪伟[1,2] 武菁菁[1] 阚建全[1,2] 

机构地区：[1]西南大学食品科学学院,重庆400715 [2]重庆市农产品加工及贮藏重点实验室,重庆400715

出　　处：《食品科学》2016年第3期43-48,共6页Food Science

基　　金：中央高校基本科研业务费专项资金项目(XDJK2015C134)

摘　　要：采用Osbron法分别提取青稞和小麦中的醇溶蛋白和谷蛋白,对这4种蛋白质进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)分析和红外光谱分析,并测定其表面疏水性、热稳定性、总巯基和二硫键含量。结果表明:醇溶蛋白在青稞蛋白质中的含量为16.96%,低于其在小麦蛋白质中的含量;谷蛋白在青稞蛋白质中的含量为47.83%,高于其在小麦蛋白质中的含量,但经SDSPAGE分析发现青稞中高分子质量谷蛋白亚基(high molecular weight glutenin subunit,HMW-GS)含量远低于小麦中的。青稞醇溶蛋白和谷蛋白中的二硫键和总巯基含量均低于小麦中的。4种蛋白的表面疏水性差异不大。青稞谷蛋白的热稳定性高于小麦谷蛋白,不利于其吸收水分和部分展开。红外光谱分析发现小麦醇溶蛋白和青稞醇溶蛋白的二级结构主要由β-转角和β-折叠组成,而小麦醇溶蛋白中的β-转角所占比例更高;青稞谷蛋白和小麦谷蛋白的二级结构主要以β-折叠为主。Gliadin and glutenin were extracted from highland barley and wheat using the Osbron method, their physicochemical properties including subunit compositions, secondary structure, surface hydrophobicity, the rmal stability, and active and total sulfydryl grou ps were measured. The results showed that gliadin content in highland barley protein was 16.96%, lower than that in wheat protein; glutenin content in highland barley protein was 47.83%, higher than that in wheat protein; however, highland barley contained less high molecular weight glutenin subunit（HMW-GS） bands wheat. The total sulfydryl and disulfi de bond contents of gliadin and glutenin in highland barley were lower than those of wheat, respectively. The hydrophobicity of gliadin and glutenin from highland barley and wheat showed a similarity. Highland barley glutenin showed higher thermal stability compared with wheat glutenin. The secondary structure of gliadin and glutenin was studied by circular dichroism, and β-pleated sheet was dominant in glutenin. The major secondary structures were β-pleated sheet and β-sheet in gliadin while β-sheet content of highland barley gliadin was lower compared with wheat gliadin.

关 键 词：青稞 醇溶蛋白 谷蛋白 面筋 

分 类 号：TS201.2[轻工技术与工程—食品科学]