Insights into improvement of the physicochemical and structural properties of wheat bran powder via combined effects of superfine grinding and glutenin

Abstract

The bond agglomeration of wheat bran (WB) powder with superfine grinding (SG) time extension is a technological barrier to its application in wheat flour. Gluten protein is considered to be the main component contributing to whole wheat flour quality. The effect of SG combined with glutenin treatment on the physicochemical and structural properties of WB powder was investigated in this study. The results indicated that when the crushing time reached 30 min, the combination of SG and glutenin treatment significantly reduced the D_v50 value to 15.60 μm and the span value to 2.57, while increasing the soluble dietary fiber (SDF) content to 8.64% of WB compared to the use of either SG or glutenin treatment individually. Besides, the combination of SG and glutenin in comparison to SG alone facilitated the destruction of crystalline regions and the regulation of internal functional groups of cellulose and hemicellulose, resulting in a reduction of the crystallinity from 28.65% to 22.34%. Furthermore, treatment with both SG and glutenin augmented the absolute value of the surface height difference to 33.6 nm, which can be attributed to enhanced surface roughness, smaller fiber fragments, and flexible porous structure. Ultimately, it is suggested that the synergistic effect of SG and glutenin treatment on the improvement of the physicochemical and structural properties of WB powder may be linked to electrostatic interactions as well as hydrogen bond interactions. Overall, these findings can promote the technological development of modulating the physicochemical properties of WB to formulate novel whole grain flours.