Static, Kinetic, and Isotherm Adsorption Performances of Macroporous Adsorbent Resins for Recovery and Enrichment of Bioactive Procyanidins from Cranberry Pomace

This study examined the ability of five Amberlite resins coupled with ultrasound-assisted water extraction for the recovery and enrichment of bioactive procyanidins and total phenolics from cranberry pomace. Static adsorption showed that XAD-7HP had the highest adsorption capacity for procyanidins (52.2 mg/g resin) and total phenolics (99.1 mg/g resin) whereas XAD-761 had the lowest. Adsorption of procyanidins fitted better to pseudo-second-order kinetics than pseudo-first-order kinetics. Isotherm adsorption on XAD-7HP suggested that Langmuir isotherm was a better model to describe the adsorption of procyanidins while Kemkin-Pyzhev equation was better for total phenolics based on higher coefficient of determinations (R-2). Dynamic tests on XAD-7HP suggested that the flow rate of 7 and 8 mL/min were the optimum conditions for adsorption and desorption of procyanidins, respectively. Measurements using HPLC revealed that adsorption increased the contents of procyanidins and total phenolics by 4.57- and 4.73-folds, respectively, compared to the initial extracts. This research showed that Amberlite XAD-7HP resin adsorption coupled with ultrasound-assisted water extraction is an efficient method to separate and concentrate procyanidins from cranberry pomace.