外源添加面筋蛋白对小麦面团热机械学和动态流变学特性的影响研究

通过向小麦粉中添加面筋蛋白粉，替代比分别为0%、5%、10%、15%、20%、25%、30%，利用混合实验仪(Mixolab)，快速粘度仪(RVA)和动态流变仪，研究添加不同比例面筋蛋白粉对小麦面团热机械学及动态流变学特性的影响。结果表明：面筋蛋白的添加使得面团的吸水率显著地从53.3%增加到67%，形成时间从1.41 min增加到9.31 min，而稳定时间随着替代比的增大，呈现先上升后显著下降的趋势，替代比为5%时达到最大值10.02 min。面筋蛋白的添加使小麦面团的峰值扭矩显著地从2.06 Nm降低到1.37 Nm，回生值从1.68 Nm降低到1.06 Nm。动态流变学试验表明：面筋蛋白的添加使得小麦面团的粘弹性特性发生明显变化，随着面筋蛋白粉比例的增加，储能模量(G′)与损失模量（G〞）呈先升高后降低的趋势；损耗角正切值tanδ则呈逐渐升高的趋势。只有在面筋蛋白粉比例为5%时的低频扫描范围内，tanδ小于对照，此时混合体系中分子交联聚合程度升高，面筋网络强度增加。
The effects of different percentages of wheat gluten on the thermomechanical and dynamic rheological properties of wheat flour dough were studied by adding wheat gluten protein powder at substitution rates of 0%、5%、10%、15%、20%、25%、30%, by using Mixolab, a rapid visco analyser (RVA), and a dynamic rheometer. The results showed that with the addition of wheat gluten, the water absorption and the dough development time significantly increased from 53.3% to 67% and from 1.41 min to 9.31 min, respectively. On the other hand, the stabilization time first increased and then significantly decreased with increasing substitution rate, with the maximum stabilization time being 10.02 min at a substitution rate of 5%. The addition of wheat gluten significantly lowered the peak torque and setback value of wheat flour dough from 2.06 Nm to 1.37 Nm and from 1.68 Nm to 1.06 Nm, respectively. The dynamic rheological test revealed that the addition of wheat gluten greatly affected the viscoelastic properties of wheat flour dough. Both storage modulus (G′) and loss modulus (G〞) first increased and then decreased, while tanδ increased with the increase of wheat gluten percentage. The only exception was the dough with 5% wheat gluten protein powder, for which tanδ was lower than that of the control when scanned in the low-frequency range. The results indicated that the extent of molecular interactions increased, thus improving the strength of the gluten network of the flour dough.