Abstract
The targeted biotransformation of plant-based dietary fibers by probiotic microorganisms offers a compelling strategy to enhance both the nutritional and technological properties of functional foods. In this study, we investigated the controlled fermentation of an oat bran matrix fortified with native chicory inulin using Bifidobacterium animalis subsp. lactis BB-12 over a 48-hour incubation period. We systematically characterized the degradation kinetics of inulin fructooligosaccharides, the accumulation kinetics of short-chain fatty acids (SCFAs), and the accompanying rheological modifications of the oat gel matrix. High-performance liquid chromatography (HPLC) analysis revealed rapid hydrolysis of inulin, yielding maximum concentrations of acetic acid (52.4 ± 2.1 mM) and lactic acid (31.8 ± 1.4 mM) at 24 hours of fermentation. Small-amplitude oscillatory shear (SAOS) rheology demonstrated that biotransformation significantly altered gel viscoelasticity; initial enzymatic liquefaction reduced the storage modulus (G'), whereas subsequent acidification and microbial metabolite generation induced a secondary sol-gel transition, yielding a structured, shear-thinning matrix with elevated yield stress (24.5 Pa). These findings demonstrate that controlled B. lactis fermentation can simultaneously maximize bioactive SCFA production and tailor the structural functionality of oat-based gel systems for novel functional food applications.
