Ultrasound-Assisted Extraction of Adenophora triphylla Polysaccharides: Optimization and Characterization of...

In this study, ultrasound-assisted extraction (UAE) of Adenophora triphylla root polysaccharides (ATRPs) was optimized using response surface methodology (RSM), and the physicochemical and functional properties of the resulting polysaccharides were investigated. A Box-Behnken Design (BBD) was applied to optimize the UAE conditions for ATRPs. The optimal UAE conditions for ATRPs with the maximum extraction yield were an extraction temperature of 34 °C, an extraction time of 41 min, and a solvent-to-solid ratio of 34 (mL/g). Under these conditions, the maximum extraction yield of UAE-ATRPs (12.46%) was significantly higher than that obtained by water extraction without sonication (WE-ATRPs, 9.76%). The results of monosaccharide composition showed that WE-ATRPs and UAE-ATRPs were heteropolysaccharides, mainly composed of glucose. In addition, FT-IR and ¹H-NMR analyses indicated that both ATRPs had α-pyranose-type glycosidic structures. The optimal UAE process reduced the glucose content from 57.70% to 53.87% relative to WE-ATRPs. Moreover, UAE-ATRPs exhibited lower solution viscosity and improved the emulsifying properties relative to WE-ATRPs. Both ATRPs also exhibited anti-inflammatory activity by inhibiting nitric oxide synthesis. In summary, our findings suggest that UAE is an effective approach for improving the extraction yield and functional properties of ATRPs, highlighting their potential applications in the food industry.