葡聚糖对大豆7S球蛋白的物性修饰

通过大分子拥挤环境下液相体系中发生Maillard反应制备大豆7S球蛋白-葡聚糖共价复合物，采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术证实大豆7S球蛋白和葡聚糖发生了共价结合。采用凝胶渗透色谱(GPC)、哈克流变仪、荧光分光光度计、紫外可见分光光度计系统研究了共价复合物的形成及葡聚糖共价键入后对蛋白特性的影响。结果表明：5%的7S球蛋白与15%的葡聚糖在pH7.0条件下，95℃反应6 h得到的产物接枝度较高，大豆7S球蛋白和葡聚糖形成了大分子的共价复合物，产物乳化活性提升了约221.7%。

Properties of soybean 7S globulin modified by dextran

Soybean 7S globulin-dextran covalent conjugate was prepared via Maillard reaction in macromolecular crowding condition in liquid system,the covalent attachment of dextran to globulin was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE).Gel permeation chromatography(GPC),Haake rheometer,fluorescence spectrophotometer and UV-visible spectrophotometer were used to confirm the formation of covalent conjugate and analyze the functional characteristics of protein after the covalent attachment of polysaccharide.The results showed that 5% 7S globulin and 15% dextran in pH7.0,at 95℃ for 6 h,obtained higher degree of grafting.Soybean 7S globulin and dextran macromolecule covalent conjugate was formed.GPC spectra showed that the reaction products of 7S globulin and dextran were composed of a mixture of various molecular weights.Within a specific range,apparent viscosity of the covalent conjugate gradually increased with increasing reaction time.The emulsification activity of covalent conjugate increased by about 221.7%.