Frankfurters inoculated with Listeria monocytogenes were treated with 1% cetylpyridinium chloride (CPC) or with 1%
CPC followed by a water rinse at various combinations of spray temperatures (25, 40, and 558C), spray pressures (20, 25,
and 35 psi), and times of exposure (30, 40, and 60 s). No significant differences (P > 0.05) were observed in the reductions
achieved by 1% CPC + water wash and those achieved with 1% CPC treatment alone. L. monocytogenes populations were
reduced by ca. 1.7 log CFU/g immediately following treatment, with no differences (P > 0.05) observed for different spray
temperatures, pressures, or exposure times. The effectiveness of 1% CPC spray treatment (at 258C, 20 psi, and 30 s of exposure)
against L. monocytogenes on vacuum-packaged frankfurters stored at 0 and 48C for 42 days was then evaluated. Application
of a 1% CPC surface spray to frankfurters immediately prior to packaging reduced L. monocytogenes concentrations by 1.4
to 1.7 log CFU/g and further restricted growth of the pathogen during 42 days of refrigerated storage, thereby meeting U.S.
Department of Agriculture alternatives 1 and 2 criteria for Listeria control. CPC treatment reduced aerobic plate counts, lactic acid bacteria, yeasts and molds, total coliforms, and Escherichia coli populations on noninoculated frankfurters to below detectable limits. The 1% CPC treatment did not affect the color (L*, a*, and b* values) of frankfurters stored for 42 days at 0 or 48C (P > 0.05). The effect of 1% CPC treatment on the firmness of frankfurters was also negligible.
