Effects of organic matter on acidic electrolysed water for reduction of foodborne pathogens on lettuce and spinach

Aims: To evaluate the efficacy of acidic electrolysed water (EW) in the presence of organic matter (bovine serum) on the inoculated surfaces of lettuce and spinach. Materials and Results: Lettuce and spinach leaves were inoculated with a cocktail of three strains each of Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes and treated with deionized water, acidic EW and acidic EW containing bovine serum (5, 10, 15 and 20 ml l^?1) for 15 s, 30 s, 1 min, 3 min and 5 min at room temperature (22 ± 2°C). In the absence of bovine serum, acidic EW treatment reduced levels of cells below the detection limit (0·7 log) in 5 min. In the presence of bovine serum, bactericidal activity of acidic EW decreased with increasing serum concentration. Conclusions: Organic matter reduces the effectiveness of acidic EW for reducing pathogens on the surfaces of lettuce and spinach. Significance and Impact of the Study: From a practical standpoint, organic matter reduces the efficacy of acidic EW. This study was conducted to confirm the effect of organic matter on the properties of acidic EW in the inactivation of foodborne pathogens on the surface of vegetables.