聚乙二醇对大豆分离蛋白美拉德反应和功能特性的影响

Effect of Polyethylene Glycol on Functional Properties of Soy Protein Isolate in Maillard Reaction

利用聚乙二醇(Polyethylene glycol,PEG)使大豆分离蛋白(Soy protein isolate,SPI)与葡聚糖(Dextran,D)在拥挤液体系下进行美拉德结合反应,通过提高PEG质量浓度改变溶液中的溶质拥挤程度,探究不同拥挤程度对SPI-D美拉德反应的影响,并研究SPI-D复合物结构的变化。利用接枝度和十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)研究不同PEG质量浓度下SPI-D复合物的结合情况,通过红外光谱、表面疏水性、游离巯基含量、溶解度及乳化性能等分析不同糖化程度对SPI的结构变化及功能性质表达的构效关系。结果表明:随着PEG质量浓度的增加,复合物结合程度不断加深,蛋白结构发生改变,α-螺旋等结构减少,无规则卷曲增加,表面疏水性不断降低,乳化性能持续改善。当PEG质量浓度在0.06 g/mL以上时,SPI-D复合物糖化增速放缓。

The binding degree of soy protein isolate(SPI)to dextrans(D)was changed by increasing the concentration of polyethylene glycol(PEG)by using PEG to bind the SPI and D through Maillard in a crowded liquid system.By increasing the concentration of PEG to change the degree of solute crowding in the solution,the effects of crowding at different degrees on the SPI-D Maillard response were investigated,and the changes in the structure of the SPI-D complexes were studied.Macromolecular crowding effect as a new concept in life science was introduced to the present study.In recent years scientists strongly suggested that much like pH value,ionic strength,or solution composition,the degree of molecular crowding should be considered as an important factor for describing the environmental conditions in a solution.The free amino group content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)were used to study the binding of SPI-D complex under different PEG concentrations.The infrared spectrum was used to indicate the hydrophobicity,free sulfhydryl content and turbidity analysis.And structure-activity relationship analysis of different saccharification degrees structural changes and functional properties of the expression of SPI emulsifying properties.The results showed that with the increase of PEG concentration,the degree of complexation of the complexes was increased,the structure of the protein was changed,the structure ofα-helix was decreased,the irregular curl was increased,the hydrophobicity was decreased,and the emulsification performance continued to be improved.When the PEG concentration was 0.06 g/mL or more,the saccharification growth rate of the SPI-D complex was slowed down.