Improved physicochemical and functional properties of soluble dietary Fiber from wheat bran by bacterial-enzymatic...

To enhance the extraction yield and functional value of soluble dietary fiber (SDF) from wheat bran (WB), a novel bacterial-enzymatic synergistic pretreatment was developed in this study, which increased the SDF yield from 3.12% to 5.72%. Structural analyses indicated increased rhamnose and galacturonic acid content, suggesting selective release of RG-I-type pectin. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) confirmed reduced crystallinity, higher surface area, and a multi-level pore structure. Functionally, the modified SDF showed improved water/oil-holding capacity (WHC and OHC), in vitro adsorption capacities (cholesterol and glucose adsorption capacities), and antioxidant activity. In vitro assays demonstrated that modified SDF alleviated OA-induced lipid accumulation and oxidative stress in HepG2 cells, reducing AST/ALT leakage and exhibiting significant hepatoprotective and lipid-lowering effects. This work offers a sustainable strategy for upgrading agricultural byproducts into functional food ingredients with health benefits.