五味子四种组分蛋白结构、理化性质和功能特性比较

Comparison of protein structure, physicochemical properties, and functionalproperties of four components in Schisandra chinensis

以北五味子脱脂粉为原料,通过奥斯本四步法提取清蛋白、球蛋白、醇溶蛋白和谷蛋白,分析比较4种组分蛋白的结构、理化性质和功能特性。结果表明,4种组分蛋白所含有的营养成分差异显著,其中谷蛋白的蛋白质含量最高而脂肪含量最低,同时蛋白提取率最高;4种组分蛋白还原性电泳和非还原型电泳在10~180 kDa和3.3~33.0 kDa亚基条带分布存在差异,超低分子质量电泳发现醇溶蛋白分子质量分布于5 kDa;扫描电镜观察出4种组分蛋白不同的表面结构和聚集程度,谷蛋白最为松散;傅里叶变换红外光谱证实了不同组分蛋白二级结构的差异。此外,谷蛋白的热稳定性、溶解性、持水性、持油性、乳化性和乳化稳定性及起泡性和泡沫稳定性均为最优,揭示出4种组分蛋白组成和结构的不同,导致其表现出的理化性质和功能特性也存在差异。

Albumin,globulin,gliadin,and glutelin were extracted from the defatted powder of Schisandra chinensis by the four-step method of Osborne.The structure,physicochemical properties,and functional properties of the four fractional proteins were analyzed and compared.Results showed that the nutritional components of the four protein fractions were significantly different,the protein content of glutelin was the highest while the fat content was the lowest,and the protein extraction rate was the highest.There were differences in the subunit bands of 10-180 kDa and 3.3-33.0 kDa between reductive and non-reductive electrophoresis,and the molecular weight of gliadin was 5 kDa by ultra-low molecular weight electrophoresis.Scanning electron microscope(SEM)showed different surface structures and aggregation degrees of the four fractional proteins,and glutelin was the loosest.Fourier transform infrared absorption(FTIR)spectra confirmed the differences in the secondary structures of different protein components.In addition,the thermal stability,solubility,water holding capacity,oil holding capacity,emulsification and emulsification stability,and foamability and foam stability of glutelin were all optimal,revealing that the composition and structure of the four proteins were different,leading to differences in their physicochemical properties and functional properties.