Effectiveness of UVC-Assisted Fenton Reaction Wash-Based System to Inactivate Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes on Cherry Tomatoes

Authors: Fan, Xuetong; Gurtler, Joshua; Baik, Jessica; Garner, Christina; Vinyard, Bryan

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2025
Publication Date: 6/4/2025
Citation: Fan, X., Gurtler, J., Baik, J.I., Garner, C.M., Vinyard, B.T. 2025. Effectiveness of UVC-Assisted Fenton Reaction Wash-Based System to Inactivate Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes on Cherry Tomatoes. Journal of Food Protection. 88(8). https://doi.org/10.1016/j.jfp.2025.100555.
DOI: https://doi.org/10.1016/j.jfp.2025.100555

Interpretive Summary: Chlorine is a sanitizer, widely used by the fresh produce industry, to minimize pathogen cross contamination during postharvest washing of fresh produce. However, chlorine has limited effectiveness in reducing populations of pathogens on the surfaces of fresh produce, and can lead to the formation of potentially harmful byproducts. Therefore, more effective and safer intervention technologies are desirable to replace chlorine. In the present study, iron ions, ultraviolet light, and hydrogen peroxide were combined to inactivate Salmonella, Listeria and E. coli on tomatoes. Results showed that the combination can reduce populations of the three pathogens by 99.7-99.999%. Future studies will be conducted to further improve the efficacy. The research provides the fresh produce industry a promising chlorine alternative for mitigating the risk of foodborne diseases.

Technical Abstract: The Fenton reaction results when hydrogen peroxide (H2O2) combines with the ferrous ion (Fe2+), producing highly antimicrobial hydroxyl free radicals (·OH). In this study, a UV-assisted Fenton reaction was tested against cocktails of Salmonella Typhimurium, E. coli O157:H7 and Listeria monocytogenes inoculated onto cherry tomatoes. Inoculated cherry tomatoes were subjected to 2% H2O2 wash, 1 mM Fe3+ wash, or exposure to UV-C during washing and simultaneously in the following combinations: H2O2 + Fe3+, H2O2+UV-C, or H2O2+Fe3++UV-C for 2 min. In addition, hydroxyl radicals were measured after combining Fenton reaction components in water. Results revealed that H2O2 alone, or in combinations, reduced higher populations of the three bacterial pathogens when compared with water wash alone. The reduction of Salmonella populations by the H2O2+Fe3++UV-C treatment was 5.24 log CFU/fruit, which was significantly greater than those reduced by Fe3+ or UV-C alone. However, the reduction was not statistically significant when compared to H2O2, H2O2 + Fe3+ or H2O2+UV-C. Similarly, the combinations did not inactivate significantly more E. coli O157:H7 and L. monocytogenes than individual H2O2 or UV-C treatments, although ·OH were produced in water during the H2O2 + Fe3+ + UV-C treatments. Overall, our results demonstrated that UV-assisted Fenton had limited advantages over individual H2O2 or UV-C treatments.