This study employed ultrasound-assisted extraction (UAE) to isolate polysaccharides from Lyophyllum decastes, which were subsequently fractionated into two components, LDP-A1 and LDP-B1, using DEAE cellulose-52 and Sephacryl S-500. The structural characteristics of the polysaccharides were preliminarily analyzed using high-performance liquid chromatography (HPLC), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Congo red staining. The results indicate significant differences between LDP-A1 and LDP-B1 in terms of molecular weight, monosaccharide composition, and structural features. LDP-A1 (2.27 × 10⁶ Da) exhibits a significantly higher molecular weight compared to LDP-B1 (9.80 × 10⁵ Da), with distinct differences in monosaccharide types and content. Both polysaccharides contain β-glycosidic bonds. LDP-B1 adopts a sheet-like structure with an amorphous internal arrangement and a triple-helix configuration, whereas LDP-A1 is rod-shaped, with a crystalline internal structure, and lacks the triple-helix configuration. In terms of biological activity, both polysaccharides exhibit certain activities, but LDP-B1 shows significantly stronger activity in antioxidant, hypoglycemic, anti-inflammatory, and anticancer effects. In summary, LDPs exhibit significant biological activity, especially outstanding performance in antioxidant, hypoglycemic, anti-inflammatory, and anticancer effects, proving their potential for development in functional foods and pharmaceuticals. Their unique structural characteristics and diverse biological activities provide a solid theoretical foundation for further exploration of LDPs in health promotion and disease prevention, opening up new research directions and application prospects.

In this study, Lactiplantibacillus plantarum BNCC 339790 was employed to extract soluble dietary fiber (SDF) from peanut shells, followed by modification using ultrasonic, microwave, and ultra-high-pressure methods to investigate their effects on SDF properties. Ultra-high-pressure modification increased SDF's water-holding and oil-holding capacities by 1.74-fold and 2.07-fold, respectively. Characterization revealed decreased crystallinity and altered surface morphology with increased roughness and porosity after modification by the three methods. In addition, microwave-treated SDF exhibited better thermal stability. Ultrasonic treatment significantly enhanced SDF's inhibitory effects on pancreatic lipase (from 62.44 % to 83.33 %) and α-amylase (from 79.81 % to 94.94 %), demonstrated improved hypoglycemic and hypolipidemic potential. Furthermore, ultrasonically modified SDF exhibited significant anti-inflammatory activity by significantly suppressing TNF-α, IL-6, and IL-1β expression. This study provides a foundation for the further development of SDF and its promotion in functional foods and other potential applications.