马铃薯生全粉-小麦粉混粉面团特性研究

Study on the mixed-dough characteristics of raw potato flour and wheat flour

为探究马铃薯生全粉的添加量对马铃薯生全粉-小麦粉混粉面团特性的影响,测定了马铃薯生全粉不同添加量的混粉面团的拉伸特性、应力松弛特性、动态流变学特性、淀粉晶型、相对结晶度及微观结构等。结果表明:马铃薯生全粉的添加降低了混粉面团的黏弹性,其拉伸力与拉伸距离呈显著下降趋势(P<0.05),阻尼系数和松弛时间均呈下降趋势;随着动态流变仪扫描频率的增加,混粉面团弹性模量和黏性模量均呈上升趋势,tanδ均呈现先下降再上升的趋势,且在频率为4~7 Hz时达到最小值;在同一频率下,随着马铃薯生全粉添加量的增大,混粉面团的弹性模量和黏性模量呈现下降趋势,tanδ呈现上升趋势;马铃薯生全粉的添加使得混粉面团中淀粉呈现B型结构,且在添加量为15%~20%时相对结晶度达到最大值,同时马铃薯生全粉的添加会稀释混粉体系中面筋蛋白的含量,导致面团中面筋网络结构的有序性和连续性受到影响。综观马铃薯生全粉添加量对混粉体系的影响,当添加量为15%时最为合适,混粉面团有较好的品质特性。

To explore the effect of the addition of raw potato flour on the characteristics of raw potato flour and wheat flour mixture,the tensile properties,stress relaxation characteristics,dynamic rheological properties,and starch of different added amounts of raw potato flour mixed dough were measured. Crystal type,relative crystallinity and microstructure were measured as well. The results showed that the addition of raw potato flour destroyed the construction of the gluten network structure,and reduced the viscoelasticity of the mixed flour dough. The stretching force and stretching distance of the mixed flour dough showed a significant downward trend( P<0. 05). Both damping coefficient and relaxation time showed a downward trend.With the increase of scanning frequency of the Dynamic Rheometer,the elastic modulus and viscous modulus of the mixed dough showed an upward trend,and the tan δ showed a first downward and then upward trend,which reached the minimum when the frequency was 4-7 Hz. At the same frequency,as the amount of raw potato flour increased,the elastic modulus and viscosity modulus of the mixed flour dough showed a downward trend,while tan δ showed an upward trend. When the amount of raw potato flour was 10%-15%,the hardness of the pectin chain in the potato cell wall and the higher relative crystallinity of the mixed flour dough increased the hardness of the dough,and the residual stress was greater than that of wheat flour dough. The addition induced the starch in the mixed flour dough present a B-type structure,and when the amount of raw potato flour was 15%-20%,the relative crystallinity reached the maximum. Meanwhile,the addition of raw potato flour diluted the gluten protein in the mixed flour system,affecting the order and continuity of the gluten network in the dough. In addition with the influence of raw potato flour on the mixing system,15% is the most appropriate addition amount,where the mixed flour dough has better quality characteristics.