Lethality of Radio‐Frequency Energy upon Microorganisms in Liquid, Buffered, and Alcoholic Food Systems

SUMMARY This work was done to determine if 60 mc/sec R‐F energy has a selective killing effect on microorganisms other than that attributable to heat. The organisms studied were Saccharomyces cerevisiae, Escherichia coli, and Bacillus subtilis, An aqueous buffer medium was used to suspend the microorganisms for the irradiation treatments. No killing effect of the R‐F energy per se on the organisms was observed at any of the various buffer pH values, nor was there an obsevable synergistic killing effect of R‐F energy and heat on the microorganisms in any of the buffer. However, a synergistic killing effect of ethanol and heat at 48.8°C was demonstrated on S. cerevisiae. Irradiating S. cerevisiae and E. coli in several liquid foods also failed to show a selective killing effect of R‐F energy.