Ultrasonic-assisted extraction brings high-yield polysaccharides from Kangxian flowers with cosmetic potential

The purpose of this work was to ameliorate the yield of polysaccharides from Kangxian flowers (PKFs) using ultrasonic-assisted extraction (UAE) and to explore the structural features and cosmetic potential of PKFs obtained under the optimized UAE. According to response surface methodology, the optimal UAE for PKFs were liquid-to-solid ratio of 59: 1 mL/g, ultrasonic power of 404 W, time of 48 min, and temperature of 66℃, under which the yield of PKFs reached 26.8 ± 1.76 %, 2.6-folds higher than hot-water extraction. By comparing the microstructures, it can be seen that ultrasonication exerted great damage on Kangxian flowers to promote the outflow of PKFs. Various analyses revealed that the PKFs extracted with UAE were acidic polysaccharides with relatively lower molecular weights of 0.92 - 76.9 kDa, negatively charged potential of -16.3 mV, and arabinose the dominant monosaccharide followed by galactose. These structural features conferred PKFs pronounced antioxidant, moistureabsorptionandretentionproperties, showing great potential for cosmetic application.