Process Optimization for Production of Ferulic Acid and Pentosans from Wheat Brans by Solid-State Fermentation and Evaluation of Their Antioxidant Activities

Wheat bran (WB) is largely discarded during processing, resulting in wastage of the bioactive components in it, such as ferulic acid (FA) and pentosans. The aim of this study was to enhance their yield by solid-state fermentation with three filamentous fungi (Aspergillus oryzae, Rhizopus oryzae, and Aspergillus niger). Through single-factor experiments, the optimal fermentation conditions were found to be a strain of A. oryzae, an inoculation amount of A. oryzae of 4 × 105 spores/g, a moisture content of 60%, a fermentation temperature of 28 °C, and a fermentation time of 48 h. By 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods, the antioxidant activities of fermented WB were found to be significantly improved. Also, there was a good correlation between the total phenolics content (TPC) and antioxidant capacity. Briefly, fermentation not only provides a new avenue to increase the functional potential of WB, but also enhances the utilization of agricultural byproducts.