通过液相体系中的Maillard反应制备了大豆分离蛋白-葡聚糖共价复合物(SDC),采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳技术证实了大豆分离蛋白和葡聚糖产生了共价结合.利用圆二色光谱、凝胶渗透色谱以及差热扫描量热仪探讨了多糖共价键入后对大豆蛋白构象和功能性质的影响.结果表明:95%乙醇体系中,60℃下反应24 h制得的产物乳化活性较高,优于干热反应5 d的产物;蛋白质的二级、三级结构发生了变化,三级结构变得更为紧凑;热分析表明产物热稳定性提高.
Soy protein isolate-dextran conjugate(SDC) was prepared via the Maillard reaction in a liquid system.Then,the covalent binding between dextran and the protein was confirmed using the SDS-polyacrylamide gel electrophoresis technology,and the molecular conformation and functional properties of the product with covalent binding were analyzed by means of circular dichroism spectrography,GPC and DSC.The results show that the product obtained after a 24h reaction in 95% ethanol system at 60℃ possesses better emulsifying activity than that dry-heated for 5d;and that significant structural changes occur in the secondary and the tertiary structures of the conjugate,with the tertiary structure being more compact.Moreover,an improvement of thermal stability of the product is revealed via thermal analysis.