Design of a Low-Power Radio Frequency Unit and Its Application for Bacterial Inactivation under Laboratory Conditions

A lab-scale low-power free-running radio frequency (RF) oscillator operating at a frequency of 27.12 ± 0.50 MHz was developed to be suitable for fundamental microbiological research topics. Calibration and validation were conducted for two common foodborne pathogens in relevant microbiological growt...

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Bibliographic Details
Main Authors: Dmytro S. Kozak, Maria Tonti, Patricia Cuba, Julian Espitia, Vladimir S. Tsepelev, Davy Verheyen, Simen Akkermans, Jan F. M. Van Impe
Format: Article
Language:English
Published: MDPI AG 2021-11-01
Series:Applied Sciences
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Online Access:https://www.mdpi.com/2076-3417/11/23/11117
Description
Summary:A lab-scale low-power free-running radio frequency (RF) oscillator operating at a frequency of 27.12 ± 0.50 MHz was developed to be suitable for fundamental microbiological research topics. Calibration and validation were conducted for two common foodborne pathogens in relevant microbiological growth media, i.e., <i>Salmonella Typhimurium</i> and <i>Listeria monocytogenes</i> in Tryptic Soy Broth and Brain–Heart Infusion broth, respectively. The evolution of temperature, frequency, and power consumption was monitored during treatments, both with and without bacterial cells. The setup operated within the predefined frequency range, reaching temperatures of 71–76 °C after 15 min. The average power consumption ranged between 12 and 14 W. The presence of bacteria did not significantly influence the operational parameters. The inactivation potential of the RF setup was validated, demonstrating the absence of viable cells after 8 and 10 min of treatment, for <i>S. Typhimurium</i> and <i>L. monocytogenes</i>, respectively. In future studies, the setup can be used to conduct fundamental microbiological studies on RF inactivation. The setup can provide added value to the scientific field, since (i) no consensus has been reached on the inactivation mechanisms of RF inactivation of pathogens in foods and (ii) most commercial RF setups are unsuitable to adopt for fundamental studies.
ISSN:2076-3417