Comparison of rheological behavior, microstructure of wheat flour doughs, and cooking performance of noodles prepared by different mixers.

Large deformation characteristics in biaxial tensile and stress relaxation, and small deformation properties in frequency sweeping and microstructure of dough produced by three kinds of mixers were assessed in this study. Differences in noodle quality were also compared. Results indicated that dough made by vacuum or spiral mixer had good resistance to external force and good resilience. But the dough and noodles made by vacuum mixer showed the best tensile and cooking properties respectively, and had overall the best performance. Confocal microscopy revealed that the protein matrix of the three doughs formed along the direction of shear flow, whereas the starch granules of dough made by the vacuum mixer were tightly wrapped in gluten, resulting in a compact and sequential gluten network. Other samples showed signs of minor structural damage (pin mixer) or the presence of holes (spiral mixer). Assessment using Pearson correlation analysis identified a number of significant correlation coefficients between the dough rheological characteristics and noodle quality. Characterization of biaxial tensile and stress relaxation was advantageous for noodle assessment prediction. The index of flow and degree of deformation were negatively correlated with tensile properties. Frequency scanning is superior in predicting cooking and stretching characteristics of noodles. PRACTICAL APPLICATION: The research provides technical guidance for obtaining better dough in noodle processing.