FIGURE 4.

Effect of continuous gaseous ozone flow (3.21 mg m^-3 = 1.5 ppm) on the survival of L. monocytogenes LMG 23775, resuspended in meat extract and laid on expanded polystyrene coupons for 6 days of incubation at 4°C. Bars represent means (with their SD) with different capital or lowercase letters expressing significant differences from one-way ANOVA analysis (P < 0.05) for untreated or ozone-treated samples, respectively. Samples showing viable cells after the enrichment procedure are indicated with “+.”