Optimization of polyphenol removal from kiwifruit juice using a macroporous resin

The separation of polyphenols from kiwifruit juice is essential for enhancing sensory properties and prevent the browning reaction in juice during processing and storage.

The present study investigated the dynamic adsorption and desorption of polyphenols in kiwifruit juice using AB-8 resin. The model obtained could be successfully applied to predict the experimental results of dynamic adsorption capacity (DAC) and dynamic desorption quantity (DDQ). The results showed that dynamic adsorption of polyphenols could be optimised in a juice concentration of 19 °Brix, with a feed flow-rate of 1.3 mL min^-1 and a feed volume of 7 bed volume (BV). The optimum conditions for dynamic desorption of polyphenols from the AB-8 resin were an ethanol concentration of 43% (v/v), an elute flow-rate of 2.2 mL min^-1 and an elute volume of 3 BV. The optimized DAC value was 3.16 g of polyphenols kg^-1 resin, whereas that for DDQ was 917.5 g kg^-1 , with both values being consistent with the predicted values generated by the regression models. The major polyphenols in the dynamic desorption solution consisted of seven compositions.

The present study could be scaled-up using a continuous column system for industrial application, thus contributing to the improved flavor and color of kiwifruit juice. © 2016 Society of Chemical Industry.