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The continuous-flow pasteurization apparatus was presented, and the electric field within orange juice was produced via an oscillating magnetic field at 50 kHz, causing the volumetric heating of the juice with initial conductivity of 6.85 mS/cm and 8.76 mS/cm. The process principle, especially numerical relationships between excitation voltage, magnetic field, induced electric field (IEF), induced current density, and temperature profile were elaborated. When applying a rectangular wave of the voltage at 50–1000 V, the waveforms of the magnetic field and IEF in the juice were sine-like and sawtooth waves, respectively. Through electromagnetic simulation, the model was established, which indicated the indirect heating of orange juice via oscillating magnetic field was feasible. As the magnetic field increased, the outlet temperature and induced current density in the juice was improved. Notably, the 4–5 logs CFU/ml inactivation effects on aerobic bacteria, yeast and mold in orange juice could be achieved at 65 °C for 60 s after the treatment. • Engineering characteristics of induced electric field technology was elaborated. • Electromagnetic simulation model was conduced to verify its thermal effect. • Waveform of magnetic field and induced electric field was investigated. • Difference between experimental and predicted temperature was not significant. • Inactivation effects on aerobic bacteria, yeast and mold was achieved. [ABSTRACT FROM AUTHOR]

Kiwifruit juice is a popular liquid food with a large consumption. It usually needs high temperature sterilization before packaging and selling. Alternating magnetic field can produce alternating induced electric field, then a thermal effect is triggered. This study aims to explore the inner heating of kiwifruit juice via induced electric field and its impact on the physicochemical properties. Meanwhile, ultra-high temperature instantaneous sterilization (121°C, 5 s), and conventional heat treatment (93°C, 2 min) were conducted as controls, then effects were compared between these treatments. The results showed that the bacterial, mold and yeast colonies were completely eliminated, polyphenol oxidase activity decreased by 94.8%, and peroxidase activity decreased by 92.7%, at 1800 V and 6 mL/min. The induced electric field treatment and ultra-high temperature instantaneous sterilization had no significant effect on pH and titratable acid (P ≥ 0.05). Conventional heat treatment increased soluble solid content by 5.3%. The induced electric field treatment resulted in the closest color and browning index to the fresh juice owing to moderate thermal effect. It also demonstrated minimal loss on total phenols and flavonoids contents after induced electric field treatment (7.1% and 2.7%, respectively). The heating effect caused by induced electric field has great application potential for the treatment of fruit juice. • Induced electric field was utilized for direct heating of kiwifruit juice. • Contact-less thermal effect and temperature rise on kiwifruit juice was evaluated. • The microbe and enzyme could be inactivated within 7.7 s via continuous-flow treatment. • The minimal loss of total phenols and flavonoid was achieved via induced electric field. [ABSTRACT FROM AUTHOR]