Purpose: An experiment was conducted to evaluate the effectiveness of six different categories of commercially available produce washes to determine the most effective ones against a broad spectrum of foodborne pathogens on cantaloupe and watermelon.
Methods: The produce wash (sodium hypochlorite, hydrogen peroxide, liquid chlorine dioxide, peroxyacetic acid/hydrogen peroxide combinations, peroxyacetic acid/acetic acid/hydrogen peroxide combination, organic acids, and quaternary ammonium) were tested against: E. coli O157:H7, Listeria innocua, Salmonella spp., and a cocktail of Big 6 E. coli non-O157 STEC artificially inoculated on the surface of cantaloupe and watermelon. Surface treatments were applied to each melon type and reductions of pathogens were statistically determined with SAS.
Results: There were significant differences observed between produce washes, but not between melon types (P < 0.05). For both types of melons, the three most effective sanitizers observed were quaternary ammonium, peroxyacetic acid/hydrogen peroxide combination, and the peroxyacetic acid/acetic acid/hydrogen peroxide combination with 1.0 - 2.2 log CFU/g, 1.3 - 2.6 log CFU/g, and 1.3 - 3.5 log CFU/g reductions, respectively, on all tested pathogens. Additional tested washes were less consistent, with reductions ranging from 0-3 log CFU/g depending on pathogen type.
Significance: Based on study results, we determine that quaternary ammonium and peroxyacetic acid/hydrogen peroxide products were most effective against the foodborne pathogens of concern on the surface of cantaloupe and watermelon. This study is of interest to public health personnel and the fruits and vegetable industry, for the control of these pathogens in the food supply.