Purpose: The objective of this study is to evaluate the bactericidal efficacy of NEO water on Escherichia coli O157:H7, Salmonella Enteritidis, and Yersinia enterocolitica in pork.
Methods: One milliliter of each pathogen was cultured overnight (eight log CFU), washed and treated by adding 10 ml of NEO water (pH: 7.64, oxidation-reduction potential: 818 mV, free chlorine: 74 ppm). Bactericidal efficiency was evaluated by plating bacterial cultures on selective media after 15, 30, and 60 seconds of treatment. Freshly-harvested pork skin and chops (5 by 5 cm) were inoculated with target pathogens at final inoculation levels of four to five log CFU/cm2. Samples were treated with NEO water for either two or 10 minutes and plated for bacteria enumeration.
Results: In the pure culture study, bacterial populations dropped below the limit of detection (two log CFU/ml) after 30 s of treatment. No live cells were recovered with enrichment after the 60 s treatment. Significant bacterial population decreases (P<0.05) were observed from all treated inoculated pork skins, the reductions were 2.59 log CFU/cm2 for E. coli O157:H7, 2.36 log CFU/cm2 for Salmonella and 1.81 log CFU/cm2 for Yersinia. The reductions on pork chops were 0.29 log CFU/cm2 (P<0.05) for E. coli O157:H7, 0.25 log CFU/cm2 for Salmonella and 0.14 log CFU/cm2 (P<0.05) for Yersinia.
Significance: Our results suggest that NEO water has the great potential to be used as a spray treatment for carcasses and pork products.