Pasteurization mechanism on the cellular level of radio frequency heating and its possible non-thermal effect

Radio frequency (RF) heating is a novel processing technology. Non-thermal effect of RF pasteurization has been debated in the last few years. This study aimed to explore the cellular pasteurization mechanism of RF heating and its possible non-thermal effect. Constant and consistent sample temperatures were achieved using a laboratory-developed device when heated by RF or hot water (HW). Results showed that the sub-lethal rates and death rates of RF and HW-treated microorganisms were not significantly (p > 0.05) different. Mechanism studies showed that cell structural damages after RF or HW treatment were similar. The α-helix content of protein showed similar increasing trend. However, a small number of differently expressed genes were detected between RF and HW-treated microorganisms. These results indicated that no non-thermal effect of RF was observed in cell lethality or structure changes. Only slight differences were observed in gene expression between RF and HW treated microorganisms. [Display omitted] •A device used to maintain constant sample temperatures in RF field was developed.•The inactivation efficiency of RF and HW to microorganisms was the same.•Pasteurization mechanism of RF and HW was proven to be similar.