采用紫外-可见吸收光谱和荧光光谱研究了酶解小麦蛋白产物与还原糖不同加热条件下的美拉德反应及其产物。美拉德反应在紫外区240和294nm产生两个特征峰,荧光的最大激发和发射波长为347和450nm;随反应进行,紫外光吸收和荧光强度迅速增加,表明美拉德反应进入高级阶段,产生的糠醛类、呋喃酮类、吡喃酮类、噻吩类及噻唑类等小分子物质表现较大的积累速率。温度升高,强度增加速率增大。在较高温度时,紫外光吸收出现最大平稳值;荧光强度则到达最大值后降低,表明小分子物质间或与肽聚合生成大分子黑素类物质,小分子物质的积累表现消除速率,反应进入终级阶段。
The Maillard reaction of wheat protein enzymatic hydrolysates and reducing sugars has been investigated by ultraviolet-visible(UV-Vis) spectroscopy and fluorescence assay.The results indicated that on heating the mixture of hydrolysates and sugars,two characteristic UV absorption peaks and fluorescence were observed.Along with the heating,the absorption and fluorescent intensity showed a rapid increase.The increase depicted the accumulation of low molecular substances from the advanced Maillard stage.As the temperature increased,the intensity increased at higher rates.But at higher temperature,the absorption reached a plateau value,while fluorescent intensity reached a maximum and then decreased,which suggested that the low molecular substances polymerized each other or with peptides to form high molecular melanoidins,showing some eliminating rate.