Figure 3.

Reduction of E. coli O157:H7 on inoculated lean beef wafers passing through the tenderizer spray system. Data shows reductions observed relative to inoculated samples (Inoc CTL), water spray treatment (Water CTL), and 14 different antimicrobials. Groups of four data bars each represent samples processed within 1 h, 1-day, 7-days, and 14-days after treatment. Each antimicrobial data bar represents the mean of eight pairs of lean beef wafers (n = 16) and error bars represent the standard deviation of the means. The “inoculation control (Inoc CTL)” and “water control (Water CTL)” data bars represent the difference from the mean of four pairs of lean beef wafers (n = 8) conducted for each of the 14 antimicrobial trials (n = 8 × 14 = 112 wafers) and the standard deviation represents the variance within the enumerated counts of these controls. A red dotted line indicates the mean of the reduction obtained by non-lethal water displacement of inoculum (Water CTL). One-way analysis of variance (ANOVA) was applied to data within each group of four time points for each antimicrobial. Data bars with the same lowercase letter (below the bars) are not significantly different; those with different letters are significantly different (p < 0.05).