Upgrading of valuable food component contents and anti-nutritional factors depletion by solid-state fermentation: A way to valorize wheat bran for nutrition

Abstract Wheat bran is a by-product of wheat flour production used as a nutritious and economic feed ingredient, but since it possesses several anti-nutritional factors that entrap nutrients and interfere with digestion and absorption, its application is limited. The utilization of organic-rich wastes for the production of value-added products and nutritional improvement of food is a means to an end – sustainability. Here we propose addressing these challenges via fermentation by Bacillus sp. TMF–2, a strain that produces several enzymes and simultaneously, wheat bran of higher nutritional quality. Following solid-state fermentation, the soluble phenolic content of wheat bran nearly triplicated compared to the raw bran. The total proportion of polyphenols along with the antioxidant capacity and free radical scavenging rate were significantly improved, particularly the ability to reduce Fe3+ increased by 10-fold. Additionally, the activity of hydrolytic enzymes: amylase, cellulase, pectinase, mannanase, protease, and phytase increased during fermentation, whereas the level of anti-nutrient, phytic acid decreased. Among all produced enzymes, there is a special emphasis on the protease prone to degrade gluten thus resulting in gluten-free wheat bran. The results of this research could contribute to a beneficial procedure for the natural modification of wheat bran, which further augments the health benefits and utilization of wheat bran.