Enzymatic Browning Inhibition in Cloudy Apple Juice by Electrodialysis

Cloudy apple juice (pH 3.8) was acidified to pH 2.7, at 16–24°C and at a constant current density of 40 mA/cm 2 , in an electrodialysis (ED) unit composed of an AB electrocell with three compartments, a bipolar membrane (Neosepta BP‐1) and two ion‐exchange membranes (anion‐ and cation‐exchange). The treatment inhibited 81% of the activity of polyphenoloxidase and slowed enzymatic browning, indicated by a decrease in indice “a” and an increase in “L” on the Hunter Lab colorimeter scale. During ED treatments, conductivity and K + concentration in apple juice decreased by, respectively, 21% and 86%.