Abstract:

According to adsorption and desorption performance towards polyphenols, an optimal macroporous resin was chosen from D4020, NKA-9, NKA-II and AB-8 resins for purifying crude polyphenols extracted from carambola dregs. AB-8 resin was found to have the best adsorption and desorption performance towards polyphenols and consequently, was chosen. The optimal adsorption conditions of carambola polyphenols onto AB-8 resin were determined as follows: polyphenol concentration of sample solution 0.9 mg/mL, sample pH 4.5, and feeding rate 2 BV/h, and the optimal ethanol concentration and flow rate for the desorption of carambola polyphenols were 60% and 0.5 mL/min. The content of carambola polyphenols in purified products under these conditions was 58.82%.

Key words: macroporous resins, polyphenols, carambola dregs, adsorption