Abstract:Glucomannanase from Bacillus amyloliquefaciens was used to enhance the yield of soluble dietary fiber （SDF）in wheat bran. The results indicated that enzymolysis in a solid-state treatment system（pH7.0，50 ℃，4 h）achieved a 34.2% increase in the yield of SDF compared to the yield with no treatment.The SDF derived by glucomannanase treatment was structurally characterized by a lower molecular weight，finer bifurcation，an amorphous structure，and partial hemicellulose degradation，as determined by gel permeation chromatography，scanning electron microscopy，nuclear magnetic resonance analysis，thermo-gravimetric analysis，and Fourier transform-infrared spectroscopy.Meanwhile，the SDF derived by glucomannanase treatment demonstrated increased water-holding and antioxidant capacities.The influence of the addition of SDF on the rheological properties of dough was further investigated.A lower storage modulus（G′），loss modulus（G″），and thixotropy of the dough was achieved，which may have contributed to its reduced starch swelling capacity，as further supported by significantly reduced peak viscosity，trough viscosity，and final viscosity during the starch pasting progress.This study highlights a novel approach for the utilization of the wheat bran as a food ingredient.