Purification of polyphenols from kiwi fruit peel extracts using macroporous resins and high‐performance liquid chromatography analysis

Summary An efficient strategy for the purification of polyphenols from kiwi fruit peel extracts was developed in this study. Six different macroporous resins were evaluated in static adsorption and desorption tests, and NKA ‐ II resin was used for further test because of its high adsorption capacity (21.28 mg g −1 dry resin) and desorption ratio (84.92%). The adsorption mechanism of the NKA ‐ II resin indicated that pseudo‐second‐order kinetics and the Freundlich isotherm model could adequately explain the adsorption process, and the thermodynamic tests showed that the process was endothermic, spontaneous and feasible. Furthermore, by optimising the dynamic adsorption and desorption parameters, the purity of the final polyphenols improved dramatically from 33.2% to 55.26%. In addition, the qualitative and quantitative determinations of the polyphenols before and after purification were conducted by a high‐performance liquid chromatography ( HPLC ) method. The results of this study showed that the developed method provided a promising basis for the large‐scale purification of polyphenols from kiwi fruit peel.