How manipulation of wheat bran by superfine-grinding affects a wide spectrum of dough rheological properties

The present study explored the effect of size reduction by superfine grinding on the performance and rheological properties of bran-enriched dough. Coarse (D-50 = 328.98 mu m) and superfine-ground (D-50 = 50.76 and 28.37 mu m) wheat brans were incorporated into the wheat dough to replace 10-30% of plain flour. Both fundamental and empirical tests were performed to assess the mixing properties, pasting properties, large deformation rheology, small deformation rheology, and stickiness of the dough. With the increasing amount of bran added, dough water absorption capacity increased, while the dough became less sticky and more rigid. Superfine grinding reduced the water retention capacity of the bran by 17-20%. Dough fortified with the finest bran (D-50 = 28.37 mu m) showed an overall better stability and uniaxial extensibility. However, the results suggested that superfine grinding not necessarily improve every aspect of dough performance, particularly the pasting properties. High peak and final viscosity were observed for dough fortified with superfine bran, indicating their end products, such as noodle, might exhibit high stickiness after cooking, and a high degree of starch retrogradation. Results of this study contributed to a better understanding of the modification effect of superfine grinding on dietary fibre.