Effectiveness of stable ozone microbubble water on reducing bacteria on the surface of selected leafy vegetables

Abstract

Effectiveness of a novel developed sanitizer, stable ozone microbubble-containing water (ozone microbubble water; OMBW), on reducing 13 kinds of bacteria was evaluated in vitro. The effectiveness of dip inoculated Escherichia coli O157:H7 or naturally attached bacteria on four kinds of leafy vegetables was also evaluated. For the purpose of comparison, the effectiveness of gaseous ozone (GO), sodium hypochlorite solution (NaClO) and distilled water (DW) were also evaluated. A 5.0 to 7.4 log reduction of viable cells was observed in an in vitro study. In contrast, a 0.8 to 1.2 or 0.9 to 1.8 log CFU/g reduction in E. coli viable cells was observed after washing with OMBW or NaClO, respectively, for all tested leafy vegetables. No significant difference was observed in the effectiveness of OMBW, ozonated water (OW) and DW. No reduction of viable cells was observed after exposure of leaves to GO. Similar experimental results were observed with the naturally attached bacteria. No difference in color and appearance was observed with DW and other sanitizing treatments. These results suggest that the effectiveness of OMBW in surface decontamination of leafy vegetables is similar to that of OW.