Improved physicochemical and functional properties of dietary fiber from millet bran fermented by Bacillus natto

• Published in: Food chemistry 2019-10, Vol.294, p.79-86
• Main Authors: Chu, Jiaxi, Zhao, Haizhen, Lu, Zhaoxin, Lu, Fengxia, Bie, Xiaomei, Zhang, Chong
• Format: Article
• Language: English
• Subjects: Adsorption; Bacillus natto fermentation; Bacillus subtilis - growth & development; Bacillus subtilis - metabolism; Bioreactors; Cellulose - metabolism; Cholesterol - chemistry; Dietary fiber; Dietary Fiber - analysis; Foxtail millet bran; Free Radical Scavengers - chemistry; Millets - metabolism; Modification; Phenols - chemistry; Physicochemical and functional properties; Polysaccharides - metabolism; Spectroscopy, Fourier Transform Infrared
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2019.05.035

•Millet bran was fermented with Bacillus natto.•Fermentation significantly increased the contents of soluble dietary fiber.•Fermentation enhanced the physicochemical and functional properties of dietary fiber.•Bacillus natto fermentation is useful in the production of functional dietary fiber.•Dietary fiber from fermented millet bran can be used as a functional ingredient in food industry. Millet bran was fermented with Bacillus natto and the changes of structural, physicochemical and functional properties of its dietary fiber were investigated. Results showed that B. natto fermentation enhanced soluble DF content from 2.3% to 13.2%, and soluble DF/insoluble DF ratio from 3.1% to 19.9%. SEM and FTIR assay indicated that fermentation led to the degradation of cellulose and hemicellulose, thereby forming more porous and loose structure and polysaccharides. The binding capacities such as water and oil holding capacity, swelling capacity as well as cholesterol, bile salts, nitrite ion and glucose adsorption capacity were improved, while cation exchange capacity was not significantly changed. The total phenolic content and DPPH free radical scavenging capacity increased significantly. Overall, fermentation of millet bran by B. natto improved the structural and functional properties of its DF, which could be applied as a functional ingredient in food products.