Ultrasonic disruption effects on the extraction efficiency, characterization, and bioactivities of polysaccharides from Panax notoginseng flower

Ultrasonic disruption extraction (UDE) and heat reflux extraction (HRE) were used to extract polysaccharides (PNFPs) from Panax notoginseng flower, and the yield, physicochemical characteristics, structural characteristics, functional properties and biological activities were evaluated and compared. Results indicated that UDE changed the above properties of PNFPs. Compared with HRE (H-PNFPs), the yields, uronic acid contents, total phenolic content, total flavonoid content, water-solubility, water holding capacity, and oil holding capacity of the polysaccharides (U-PNFPs) extracted by UDE increased by 48.63%, 47.36%, 39.98%, 7.41%, 2.26%, 15.56%, and 1.34%, respectively. In comparison, the molecular weight and protein content decreased by 43.53% and 16.46%. Results demonstrate that UDE could effectively improve the physicochemical and functional properties, and bioactivities. These findings are helpful for better understanding the relationship between the physicochemical properties and bioactivities of U-PNFPs, especially U-PNFP-2 exhibited the most significant antioxidant activity, which can prevent oxidative stress, applications in food and pharmaceutical industries.