Immediately after the 20min contact time, both themediumwell roast beef and rare roast beef treatedwith antimicrobial solutions showed decreases in pH (5.14 ± 0.02, 5.61 ± 0.01, vs. 5.76 ± 0.01 for medium well roast beef, and 5.12 ± 0.00, 5.85 ± 0.01, vs. 5.97 ± 0.01 for rare roast beef,P b 0.05).