Structural characterization, functional properties, bioactivity and oral absorption characterstics of Oudemansiella raphanipies polysaccharides

The medicinal fungus <i>Oudemansiella raphanipies</i> (<i>O. raphanipies</i>) attracts significant interest for its broad-spectrum bioactivities, with its polysaccharide demonstrating particularly notable pharmacological properties. This study systematically investigated the extraction, physicochemical properties, structural, functional traits, biological activities, and oral absorption of <i>O. raphanipies</i> polysaccharide. Response surface methodology optimized the extraction condition of <i>O. raphanipie</i> polysaccharides by UAE method, achieving a yield of 210.35 ± 0.20 mg/g (55 °C, 90 min, 250 W, 1: 60 g/mL). The purified <i>O. raphanipie</i> polysaccharide (UAE-ORP) (568.57 kDa), an α-pyranose mainly composed of glucose (35.48%) and galactose (28.51%), showed high thermal stability (322 °C). In addition, UAE-ORP showed interesting water retention capacity and oil retention capacity, and good foaming and emulsion properties. UAE-ORP demonstrated potent antioxidant activity, with DPPH scavenging rate reaching 90.43% and hydroxyl radical scavenging rate at 57.13%, significant inhibition of BSA denaturation (97.49%) and NO secretion, and potential prebiotic effects. UAE-ORP was significantly distributed in the gastrointestinal tract based on NIR imaging result, retaining in intestines for 24 h, indicating its potential as a prebiotic agent. Thus, UAE-ORP is a promising functional food additive with integrated advantages.