The physicochemical characteristics and functional properties of steam explosion modified wheat bran in vitro and in vivo

Wheat bran is the processing byproduct of wheat, which is thought to have great potential applications. To make a full utilization of the resource, this study investigated the effects of steam explosion (SE) modification, with intensity at 1.0 MPa at 20, 60, 100, 140, 180, and 220 s, respectively, on wheat bran soluble dietary fiber (SDF) content, physical-chemical quality, antioxidant capacity, and intestinal microbial spectrum. The impact of long-term intake of WB100 (wheat bran modified under SE conditions of 1.0 MPa and 100 s) on weight control in obese mice was also studied. The results showed that WB100 showed a 3.36-fold increase in SDF content, a 61.78% and 109.77% increase in the DPPH and ABTS free radical scavenging rate, and maintained good hydration properties compared to the untreated group. Besides, the 5-HMF content of WB100 was 16.93 mg/kg, which was within the allowable range and ensured the safety of wheat bran. In addition, WB100 significantly increased and specifically enriched the abundance of Agathobacter, Fusicatenibacter, and Faecalibacterium after intestinal microbial fermentation. Long-term intake of WB100 in obese mice could play a role in weight control by reducing blood lipid levels and fasting blood glucose values, stimulating appetite suppression-related hormones, reducing fat accumulation, and protecting liver health. This study highlighted the importance of SE technology for the enhancement of wheat bran added value and industrial upgrading.