Abstract: In this study, AB-8 macroporous resin was used to separate and purify flavonoids from mung bean coat. To establish optimized sample loading and the elution conditions, the influence of sample concentration, pH and flow rate as well as eluent concentration, volume and flow rate on the adsorption and desorption efficiencies was investigated. The optimal conditions determined were as follows: sample concentration, 1.5 mg/mL; pH, 5.0; flow rate, 1.0 mL/min; and 225 mL of 70% ethanol as eluent at a flow rate of 2.0 mL/min. Under these conditions, the purity of mung bean coat flavonoids increased from 27.95% to 62.38%. The existence of flavonoids were confirmed by their characteristic peaks in UV-visible spectra and characteristic functional groups identified by infrared spectroscopy. Scanning electron microscopy (SEM) showed that most flaky and powdery particles were released, which might contribute to the increased purity of flavonoids after initial purification. Compared with crude extract, the purified flavonoids had higher antioxidant ability.

Key words: AB-8 macroporous resin, separation and purification, flavonoids, identification, antioxidant