Abstract: The present study tested the effect of addition of whole common buckwheat flour on the rheological properties of wheat dough, and the textural characteristics, water distribution, secondary structure and molecular mass distribution of proteins, microstructure, and color of fresh noodles. The results demonstrated that the dough with 30% whole common buckwheat flour had a higher G’ (5.3 × 105 Pa) and a minimum tan δ value of 0.50. The resulting noodles had a maximum elasticity of 0.97, a maximum α-helix content of 28.30%, and a denser and more homogenous microstructure. According to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) data, the band intensities of buckwheat protein subunits increased with increasing addition of whole common buckwheat flour. Compared with the control group, the addition of whole common buckwheat flour caused partial transformation of tightly bound water to weakly bound water and free water. As the addition of common buckwheat flour increased, the L* value of noodles decreased significantly, the a* and b* values increased to varying degrees, and as a result the overall color turned reddish and yellow. In conclusion, the addition of 30% whole common buckwheat flour can improve the mechanical properties and processing quality of fresh noodles.

Key words: whole common buckwheat flour; dough; rheological properties; noodles; texture properties; microstructure