Structural characterization, lipid-lowering activity, and emulsifying properties of polysaccharides derived from...

The biotransformation of agricultural by-products through fungal solid-state fermentation (SSF) represents a sustainable and efficient strategy for enhancing the functional properties of plant polysaccharides. Following SSF with Ganoderma lucidum, a low-molecular-weight polysaccharide fraction, designated FPP-1-b, was isolated from fermented wheat pericarp, with an average molecular weight of 2.29 kDa. FPP-1-b was composed of fucose, arabinose, galactose, glucose, xylose, and mannose in a molar ratio of 0.43:27.63:9.08:13.97:31.12:17.78. Structural analyses indicated that FPP-1-b was an arabinoxylan-rich, short-chain polysaccharide fraction containing substituted xylosyl residues and local branching features. In oleic acid (OA)-induced HepG2 cells, FPP-1-b significantly reduced intracellular TC, TG, and LDL levels, while increasing HDL content in a concentration-dependent manner within the tested range. Additionally, FPP-1-b alleviated OA-induced oxidative stress, suppressed TNF-α and IL-6 production, and reduced OA-induced elevations in intracellular ALT and AST. Contact angle analysis showed a value of 86.66°, indicating intermediate wettability and amphiphilic interfacial characteristics. Consistently, SPI/FPP-1-b emulsions containing 0.50% and 0.75% (w/v) FPP-1-b exhibited improved emulsifying activity. Collectively, these findings highlight G. lucidum-mediated SSF as an effective approach for the valorization of wheat pericarp into a functional polysaccharide with both lipid-lowering and emulsifying properties.