Adsorption/desorption characteristics and separation of anthocyanins and polyphenols from blueberries using macroporous adsorbent resins

Blueberries contain antioxidant phytochemicals, such as anthocyanins, flavonols, and procyanidins, with many reported health benefits. In the present study, phytochemicals from blueberries were extracted using ultra-sound assisted hot water extraction and concentrated with Amberlite adsorption resins. Static adsorption tests showed that FPX66 resin had a higher adsorption capacity and desorption ratio than XAD7HP and XAD4 resins. XAD761 and XAD1180 showed the lowest desorption capacity and ratio. Kinetic adsorption and isotherm tests revealed that FPX66 had the highest adsorption efficiency and required shorter time to reach adsorption equilibrium. Dynamic adsorption on FPX 66 resin in a glass column demonstrated that anthocyanins in the blueberry water extract started to break through after 16 bed volumes of extract was loaded. A complete desorption was achieved using 3 bed volumes of 95% ethanol. One hundred grams of fresh blueberries yielded 0.80 g concentrated blueberry extract. Sugars were not detected in the extract.