**5. Conclusions**

The novel proprietary technology used to produce the high concentration, and stable reactivity of the aqueous ozone solution proved promising for the reduction of *E. coli* O157:H7 detection and indicator levels in beef. The findings encountered in this study indicate that the ozone intervention is not only effective but similar in performance to lactic acid in reducing bacterial load on carcasses and trim which will improve beef safety, therefore validating its use in the beef processing environment as an effective antimicrobial intervention. Bacterial surrogate studies become of utmost importance when trying to validate interventions in a commercial processing plant setting. They more accurately represent the specific effects that the antimicrobial intervention will have against pathogens they represent in a given environment, without compromising food safety. The evaluation of in-plant data for comparative purpose of intervention schemes gives additional support to the effectiveness of this technology, with ongoing control exerted over different seasons and processing months. Further research into multiple hurdle intervention interactions must be conducted to design the most effective ways of mitigating pathogen presence and ensure beef safety.

**Author Contributions:** Conceptualization, M.F.M., M.M.B., E.R., D.L., M.X.S.-P., and A.E.; methodology, M.X.S.-P., D.A.V., D.E.C., and M.F.M.; validation, D.E.C., M.X.S.-P., E.R., D.L., and D.A.V.; formal analysis, D.E.C. and D.A.V.; investigation, M.F.M., E.R., D.A.V., and D.E.C.; resources, E.R., D.L., M.M.B., M.F.M., and A.E.; data curation, D.E.C. and D.A.V.; writing—original draft preparation, D.E.C.; writing—review and editing, D.E.C., M.X.S.-P., A.E., M.F.M., and D.A.V.; supervision, D.L., A.E., M.M.B., and M.F.M.; project administration, D.E.C., D.A.V., and M.F.M.; funding acquisition, M.M.B., M.F.M., A.E., and E.R. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded through the collaboration of the International Center for Food Industry Excellence at Texas Tech University and our industry partner Nebraska Beef Ltd.

**Data Availability Statement:** Data available on request from the corresponding author. The data are not publicly available due to privacy from the beef processing partner that allowed the project to be conducted within their beef processing environment.

**Acknowledgments:** We would like to acknowledge the help of all ICFIE Food microbiology personnel that helped inside the laboratory in processing of samples.

**Conflicts of Interest:** The authors declare no conflict of interest.
