Enhancement of ultrasound on the dynamic decolorization of wolfberry (Lycium barbarum) polysaccharides

Abstract The impact of ultrasound on the dynamic decoloration of Lycium barbarum polysaccharides (LBPs) on macroporous resins was investigated. Six resins with different properties were tested for decoloration of LBPs. D280 resin demonstrated the higher decoloration, deproteinization and polysaccharide recovery ratios through static adsorption tests. Under the optimized dynamic adsorption conditions (concentration of 0.4 mg/mL, flow rate of 2 BV/h, diameter-height ratio of 1:10), the desorption effect of acid-base sequential elution was better. Compared with conventional-assisted desorption process, ultrasound treatments enhanced the desorption process of LBP pigments and increased the service life of resin by promoting the separation of pigments from resin. Furthermore, the dynamic desorption of LBP pigments by D280 resin was clearly fitted by BDST/Thomas/Yoon-Nelson model. Ultrasound improved the desorption efficiency by increasing desorption constant K and equilibrium desorption capacity constant N0, q0. Overall, ultrasound could be an effective technology to enhance the dynamic desorption of LBP pigments.