挤压糙米粉-小麦粉混合粉面团特性研究

The Properties of Dough Prepared from Mixtures of Extruded Brown Rice Flour and Wheat Flour

将2种挤压糙米粉(物料水分25%、挤压温度120℃、螺杆转速220 r/min和物料水分30%、挤压温度80℃、螺杆转速220 r/min)分别以0%、10%、20%、30%、40%和50%的比例添加到小麦粉中(m/m),研究挤压糙米粉添加量对挤压糙米粉-小麦粉混合粉面团特性的影响。结果表明,随着挤压糙米粉(EBR)添加量的增加,混合粉峰值黏度、最低黏度、崩解值和最终黏度均逐渐减小,吸水率增加,面团稳定时间先降低后升高。EBR的添加增加了面团整体的黏弹性,但当添加量较多时(大于30%),EBR对面筋网络结构的稀释使面团蛋白质网络结构出现弱化。因此,面团弹性模量G'和黏性模量G″均先增加后减小,30%时达到最大。tanδ值先减小后增加,添加量30%时达到最小。EBR的添加量小于30%时能够同时增加面团的弹性和黏性,且弹性模量G'比黏性模量G″增加幅度要大。EBR添加量小于30%时,面团中形成了EBR黏附的不同于面筋的致密的网络结构。

Two kinds of extruded brown rice flour were prepared at moisture content of 25%, temperature of 120 ℃, screw speed of 220 r/min and moisture content of 30%, temperature of 80 ℃, screw speed of 220 r/min, respectively. The extruded brown rice flour were mixed with wheat flour at content of 0%, 10%, 20%, 30%, 40% and 50%, respectively, and the properties of dough were determined. The results showed that peak viscosity, minimal viscosity, breakdown value and final viscosity of flour mixtures decreased, waterSabsorption increased, and stabilization time of dough decreased at low addition amount and increased at high addition amount. The networks of dough protein were weaken, the elasticitySmodulus and viscousSmodulus of dough increased at low addition amount and decreased at high addition amount, and reached the maximum at content of 30%. Tanδ value of dough decreased at low addition amount and increased at high addition amount, and reached the minimum at content of 30%. The elasticity and viscidity of dough were increased when the content of EBR was less than 30%, and the increase degree of dough elasticity was more than that of dough viscidity. The Scanning Electron Microscope results showed that compact networks that were different from gluten network in dough were formed when the addition amount was less than 30%.