This study evaluates the frequency-effects of continuous pulsed ohmic heating (POH) on fruit juice pasteurization, using lemon juice as a worst-case model system due to its high acidity and thermolabile compounds. Fresh lemon juice was processed using continuous ohmic heating (OH, 0 kHz), POH (0.5 and 1 kHz) at voltage gradients of 40–60 V/cm, and conventional heating (CH). Results demonstrated that 1 kHz pulsing reduced iron migration by >99% (0.04–0.11 ppm) compared to continuous OH (11.62–12.20 ppm), achieving compliance with EU safety standards. All ohmic treatments achieved complete microbial inactivation (from 5.712 Log CFU/mL to non-detectable levels) with heating rates 6–13 times faster than CH (0.231 °C/s). While CH exhibited superior vitamin C retention (98.73%), POH demonstrated enhanced antioxidant activity preservation (35.69% vs. 17.54% in fresh juice). Energy consumption was substantially lower for all ohmic methods (161.57–370.26 kJ/kg) compared to CH (3.86 MJ/kg). The optimal processing condition was identified as 1 kHz at 60 V/cm, balancing microbial safety, minimal electrode corrosion, and quality preservation, establishing POH as a promising industrial pasteurization technology.
