Ionic liquid-mediated ultrasonic-assisted extraction of Curcuma phaeocaulis polysaccharides: Process optimization, structural characterization, and extraction mechanisms

An ionic liquid-mediated ultrasonic-assisted extraction (IL-UAE) method was developed for the extraction of Curcuma phaeocaulis polysaccharides (CPPs). The extraction process of IL-UAE was optimized using response surface methodology (RSM) and artificial neural networks (ANN). Compared to the RSM, the ANN model exhibits a higher R 2 value (0.9900 vs. 0.9808) and a lower Residual Sum of Squares (26.40 vs. 49.52), indicating that the ANN model has stronger explanatory power and better fitting accuracy. Additionally, this study compared the yield and physicochemical properties of CPPs obtained by the IL-UAE and hot water extraction (HWE). The results indicate that the yield of IL-UAE (3.69 %) was significantly higher than that of HWE (1.51 %). Furthermore, the CPPs extracted using IL-UAE possess higher arabinose and galactose contents, a larger molecular weight, and better anticoagulant activity. Notably, the physicochemical properties and the density functional theory calculations demonstrated that IL-UAE could fragmentate the cell wall and interact with the target polysaccharides. This study offered a promising method for the extraction of functional polysaccharides using environmentally friendly solvents. • A new method was developed to extract C. phaeocaulis polysaccharides. • Two models were used to optimize the extraction of C. phaeocaulis polysaccharides. • The physicochemical properties of C. phaeocaulis polysaccharides were studied. • The extraction mechanism of the new method was clarified.