Figure 4.

Reduction of E. coli O157:H7 in antimicrobial spray-treated, blade-tenderized beef as determined from individual core sections recovered after processing (i.e., inoculation, spray treatment, blade tenderization, core excised, sectioning, blending, enrichment, and microbial plating). Results for each treatment (four cores/treatment; four sections/core; n = 16 sections) were determined for the presence/absence of our inoculated E. coli 157:H7 strains. Negative controls represented inoculated but non-tenderized beef (Neg CTL), while positive controls represented inoculated and tenderized beef (Pos CTL). Positive and negative controls were sprayed with water instead of antimicrobials. Error bars represent standard deviation of E. coli O157:H7 presence (versus absence) within each set of the four replicate core samples, while bar height is the total of positive sections among four replications. Pairwise analysis of variance (Holm-Sidak method) of treatments with different letters represents significant differences (p < 0.05); data bars with the same letters are not significantly different.