Fortification of Bioactive Compounds in Roasted Wheat Bran by Solid-State Fermentation Using Bacillus subtilis HA

• Published in: FOOD SCIENCE AND TECHNOLOGY RESEARCH Vol. 23; no. 3; pp. 395 - 402
• Main Authors: Lim, Ji-Yeon, Jang, Geun-Min, Garcia, Coralia V., Lee, Sam-Pin
• Format: Journal Article
• Language: English; Japanese
• Published: Tsukuba Japanese Society for Food Science and Technology 2017; The Japanese Society for Food Science and Technology; Japan Science and Technology Agency
• Subjects: Acidity; Amino acids; Bacillus subtilis; Bioactive compounds; Biocompatibility; Dietary fiber; Fermentation; Fermented food; Flour; glutamate; Glutamic acid; Moisture content; Mucilage; Peptides; pH effects; poly-γ-Glutamic acid; Solid state fermentation; Solids; Tyrosine; Wheat; Wheat bran
• ISSN: 1344-6606; 1881-3984
• DOI: 10.3136/fstr.23.395

Roasted wheat bran flour (RWBF) was fermented by Bacillus subtilis HA to produce bioactive compounds including mucilage and peptides. A moisture content of 60% was optimal for the solid-state fermentation, which exhibited the highest mucilage productivity after 1 day. Adding MSG to the substrate resulted in increased viable cell counts and mucilage and decreased acidity. After 1 day of fermentation, the RWBF containing 5% MSG indicated pH 6.5, mucilage content of 11.5%, consistency index of 5.59 Pa·sn, viable cell counts of 6.25 × 108 CFU/g, 4.0 mg/g tyrosine equivalents, and protease activity of 20 U/g. The total content of free amino acids tended to decrease during the alkaline fermentation, in particular, that of glutamate, indicating that the added MSG was efficiently converted to poly-γ-glutamic acid, with an 80% yield. The proposed solid-state fermentation is an effective approach to produce a highly valuable ingredient from wheat bran.