Solid-state fermentation by Aspergillus niger and Lactobacillus plantarum improved the nutritional and physicochemical properties of wheat bran and whole wheat bread

Abstract Solid-state fermentation (SSF) is an economically viable processing technique to improve the bioactive content from agricultural by-products. The impacts of SSF by Aspergillus niger (AN) and Lactobacillus plantarum (LP) on the physicochemical and functional properties of wheat bran and whole wheat bread were investigated in this study. Compared with unfermented wheat bran, the pH of fermented wheat bran decreased significantly, and the titrated acidity increased significantly. The water absorption index, water solubility index and swelling capacity of wheat bran were significantly increased after fermentation. Besides, the free-radical scavenging activities for DPPH, ABTS and the total antioxidant capacity of wheat bran were notably increased after SSF. Moreover, the content of alkylresorcinols (ARs), total phenolics and flavonoids compounds in wheat bran were enhanced by 137.85%, 52.87% and 95.6%, respectively, after fermentation. The content of aflatoxin B1, deoxynivalenol, zearalenone and ochratoxin A were decreased by 76.34%, 18.67%, 34.48% and 20.46%, respectively. SSF enhanced the content of ARs, total phenols and flavonoids in the reconstituted whole wheat bread by 136.55%, 54.55% and 97.74%, respectively. Whereas, the hardness and chewiness of the bran-rich bread were decreased by 75.2% and 92.41%, respectively. Additionally, the sensory evaluation score, specific volume and the overall score of reconstituted bread were significantly improved. Taken together, SSF by AN and LP could improve the processing value of wheat bran and might be a feasible solution to upgrade whole wheat product quality.