Effects of milling methods on rheological properties of fermented and non-fermented dough

The rheological properties of wheat flour are very important for the production of bakery products, and the milling methods greatly influence the rheological properties. In this paper, we measured the particle size distributions, damaged starch contents, granular morphology, and pasting properties of the wheat flour, also carried out the uniaxial elongation test, the texture profile analysis, and rheological properties of the dough to evaluate effects of two milling methods, i.e. impact mill (IM) and hammer mill (HM), on the rheological properties of wheat flour and dough. The results showed that milling methods had no significant effects on flour pasting temperature (except the flour H3 obtained by HM grinding three times) and springiness of dough. Flour samples milled by IM had a lower damaged starch content, higher trough viscosity, higher final viscosity and higher values of setback compared to samples processed by HM. After repeated milling of IM, the damaged starch content of the endosperm granules could be controlled below 1% (P < 0.05). There was a gap between H1 and H2 in the elastic modulus value of the non-fermented dough group, and the difference increased after fermentation, which was more obvious in the values of viscosity modulus. The more the milling times, the greater the elastic and viscosity modulus of dough of flour processed by both IM and HM.