Comparative Screening of Resin-Based Extractions of Phenolic Compounds from Aronia mitschurinii

Aronia mitschurinii, an antioxidant enriched hybrid of Aronia melanocarpa and Sorbus aucuparia, contains one of the highest known levels of bioactive compounds associated with a range of health benefits, including antidiabetic, anti-inflammatory, anti-obesity, and positive cardiovascular effects. Despite possessing one of the highest reported antioxidant contents among fruits, the bitter taste of tannins and polyphenols reduces its marketability in the nutraceutical market. Conventional approaches to reduce tannin-related bitterness rely on thermal processing, which can degrade important antioxidant compounds, such as anthocyanins. This study investigates the extraction of phenolic antioxidants from Aronia mitschurinii juice by comparing seven Mitsubishi Chemical resins with FPX66, a resin previously tested and found to be the best among Dow Chemical resins for antioxidant extraction. Each resin was assessed following activation with acetone, 50% ethanol, and 100% ethanol using gentle and rough adsorption treatments to compare the desorption concentrations of polyphenols, flavonoids, and anthocyanins. Phase-contrast microscopy was used to evaluate resin structural integrity after treatment. Adsorption kinetics were also evaluated, and column-based extraction was performed with FPX66, SP825L, and SP850. The batch adsorption kinetics approached a plateau after approximately 180 min, while FPX66, SP825L, and SP850 approached equilibrium within approximately 40–60 min under column conditions. Among the resins tested, SP825L and SP850 showed strong desorption performance while maintaining their structural integrity. During column testing, SP825L produced 30% higher polyphenol, 70% higher flavonoid, and 43% higher anthocyanin desorption concentrations than FPX66, while SP850 produced 22%, 47%, and 11% higher concentrations, respectively. Overall, SP825L provided the best balance between high antioxidant desorption concentrations and resin structural stability under the conditions tested.