The effectiveness of closed-circulation gaseous chlorine dioxide or ozone treatment against bacterial pathogens on produce

The objective of this study was to examine the effectiveness of gaseous chlorine dioxide (ClO2) or ozone (O3) treatment against Shiga toxin-producing Escherichia coli (STEC), serovars of Salmonella enterica, and Listeria monocytogenes on baby-cut carrots, lowbush blueberries, and beefsteak tomatoes using a scaled-up closed-circulation treatment system. Dry ClO2 precursors were combined in-chamber to make 0.03, 0.06, and 0.12 mg ClO2/g produce for a 2.5 h exposure and 0.04, 0.07, and 0.15 mg ClO2/g produce for a 5.0 h exposure time. Ozone was generated through corona-discharge of a dry oxygen feed and either 0.86 or 1.71 μg O3/g produce concentrations were used to treat 2 kg of produce for 2.5 and 5.0 h.