A Novel Aqueous Ozone Treatment as a Spray Chill Intervention against Escherichia coli O157:H7 on Surfaces of Fresh Beef

Abstract

This experiment determined the efficacy of using a novel aqueous ozone treatment as a spray chill intervention to reduce Escherichia coli O157:H7 on surfaces of fresh beef compared with traditional water spray chill. Cutaneous trunci muscles were obtained from a local beef cattle processing plant. Muscles were divided into sixteen 25-cm2 sections, and each section was individually inoculated with E. coli O157:H7 to the final concentration of approximately 105 CFU/cm2. Muscle sections were collected and tested before and after simulated spray chill treatments of water or the novel aqueous ozone solution. Enumeration of survivors of each treatment was compared with that of the untreated muscle sections. Water spray chill reduced (P ≤ 0.05) E. coli O157:H7 0.60 log, whereas the aqueous ozone spray chill reduction (P ≤ 0.05) was 1.46 log on surfaces of fresh beef. Aqueous ozone spray chill reduced (P ≤ 0.05) aerobic bacteria 0.99 log, but water spray chill did not significantly (P > 0.05) reduce aerobic bacteria on surfaces of fresh beef. The findings indicate that aqueous ozone can be used as a spray chill intervention to enhance the safety of beef.