绿豆蛋白对荞麦淀粉糊化和流变特性的影响

Effect of Mung Bean Protein on Gelatinization and Rheological Properties of Buckwheat Starch

为探究蛋白质对淀粉性质的影响,以荞麦淀粉为原料,将不同比例的绿豆蛋白添加到荞麦淀粉中,应用快速黏度分析仪、流变仪、质构仪等研究绿豆蛋白对荞麦淀粉糊化特性、流变特性、质构特性及微观结构的影响。结果表明:绿豆蛋白提高了荞麦淀粉的糊化时间、糊化温度,并降低了峰值黏度、终值黏度、崩解值及回生值;不同比例的绿豆蛋白使荞麦淀粉糊的剪切应力不同程度降低,稠度系数K降低,体系仍为假塑性流体,其中荞麦淀粉与绿豆蛋白质量比为8∶2的复配体系剪切变稀现象更为明显;添加绿豆蛋白使荞麦淀粉的储能模量、损耗模量均降低,损耗角正切值升高,凝胶强度变弱;复配体系的硬度、胶黏性、咀嚼性均降低;通过扫描电镜观察可知,凝胶在微观上呈蜂巢状结构,且随着绿豆蛋白添加比例的增大,蜂巢孔隙变大,孔壁变薄。

In an attempt to explore the effect of protein on starch properties,we measured the pasting,rheological and textural properties and microstructure of buckwheat starch added with different proportions of mung bean protein utilizing a rapid visco analyzer,a rheometer and a texture analyzer.The results showed that the pasting time and temperature of buckwheat starch were increased while peak viscosity,final viscosity,breakdown value and setback value were reduced by adding mung bean protein.As the addition of mung bean protein increased,shear stress and consistency coefficient K declined while the starch paste was still a pseudoplastic fluid.An 8:2 ratio of mung bean protein to buckwheat starch showed more significant shear thinning.Both storage modulus(G’)and loss modulus(G”)were reduced,loss angle tangent(tanδ)was increased and gel strength was weakened by the addition of mung bean protein.Moreover,the hardness,gumminess and chewiness of the starch gel were significantly decreased and the elasticity became slightly lower.As observed by scanning electron microscopy(SEM),the starch gel showed a honeycomb-like microstructure with the pores becoming larger and the cell wall becoming thinner with increasing addition of mung bean protein.