Adsorption equilibrium, kinetics and dynamic process of polyphenols from orange peel extract on mixed‐mode adsorption resin HD‐1

Abstract

AbstractBACKGROUNDThe extraction and separation of natural polyphenols are attractive. Many researchers used high‐speed counter‐current chromatography to separate and purify polyphenols. However, it requires a long operating time, a large amount of organic solvent consumption, and high operating costs. In this work, the adsorption behaviors of polyphenols from orange peel extract on mixed‐mode resins were studied. The adsorption capacities and selectivities of different resins to the main polyphenols in the extract including gallic acid, p‐coumaric acid and ferulic acid were compared. The adsorption mechanism was analyzed by adsorption equilibrium and kinetics studies as well as molecular docking. The fixed‐bed adsorption was studied experimentally and theoretically.RESULTSHD‐1 resin has excellent adsorption selectivities among the resins. The yield of polyphenols from orange peel by integrated extraction‐adsorption increased by 82.94% compared with that of extraction without adsorption. The adsorption isotherms agreed with the Freundlich model. Dubinin–Radushkevich model results indicated that the adsorption of gallic acid mainly depends on nonelectrostatic interaction. The adsorption of the other two polyphenols involves electrostatic and nonelectrostatic interaction. The adsorption kinetics curves accorded with the pseudo‐second‐order model, and the adsorption rate of gallic acid was the highest among the polyphenols. Adsorption of polyphenols involves both physical and chemical adsorption. The breakthrough curves could be closely simulated by Yoon–Nelson and Thoms models. Significant differences existed in times for 50% breakthrough.CONCLUSIONMixed‐mode chromatography with HD‐1 resin as stationary phase is applicable to the separation of polyphenols. © 2024 Society of Chemical Industry (SCI).