Physicochemical properties of apple juice influenced by induced potential difference (induced electric field) during disposable continuous-flow treatment

A disposable continuous-flow system was established by treating apple juice with induced electric field (IEF). Under synchronous alternating magnetic flux, rather than electrodes, the electrical treatment was implemented in multi-series coils consisting of the flowing sample. An activation effect at 50 °C and inactivation effect at 70 °C were observed under IEF. High excitation voltage (900 V) caused a significant decrease in the residual activities (RA). As the flow rate decreased from 87.5 to 17.5 mL/min, RA of PPO and POD were changed without applying IEF indicated shear effect of the pump had an impact on the RAs. At 17.5 mL/min, PPO was inactivated after IEF treatment for 7.6 min. In compared with the control (0 V), the fluid impedance was increased at 70 °C and 80 °C under IEF, whereas it was decreased at 30 °C and 40 °C. IEF had no adverse influence on the color and volatile compounds of apple juice in this system.