Anti-Listeria of H2O2-Peroxyacetic acid Anti-Listeria Efficacy of a Hydrogen Peroxide-Peroxyacetic acid Mixer in Bacterial Buffered Solution and on Bell Peppers

Author

Peighton Denae Foster, West Virginia UniversityFollow

Author ORCID Identifier

https://orcid.org/0009-0009-5131-0029

Semester

Spring

Date of Graduation

2024

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Animal and Nutritional Sciences

Committee Chair

Cangliang Shen

Committee Member

Annette Freshour

Committee Member

Jacek Jaczynski

Abstract

This study aims to 1) evaluate the efficacy of H₂O₂-peroxyacetic acid (PAA) mixer to inactivate Listeria monocytogenes in 0.1% buffered-peptone-water; 2) evaluate the reduction and mitigation of cross-contamination on peppers. For the study-1, aliquots of 1.0-ml mixer solutions (0.25, 0.50 and 0.84%) were added to the first 3-well of 8-strip-deep-well microplates. Then, the 0.1 ml of 10-fold dilution the Nalidixic-acid-resistant (NaL) L. monocytogenes was added and mixed immediately with a multichannel pipette. After exposure for 0, 5, 15, 30, and up to 120-s, 1 ml of 2×D/E neutralized solution was added to terminate the reaction followed by spread-plating onto tryptic soy agar plus 200 ppm NaL and incubated at 35^oC for 48 h. For the study-2, 5 inoculated red peppers were triple-washed with 15 uninoculated green peppers with 0, 0.05, 0.1, and 0.18% H₂O₂-PAA and analyzed using MPN-method. L. monocytogenes counts were 10CFU/ml after exposing to 0.25, 0.50, and 0.84% H₂O₂-PAA solution for 120, 90 and 60 s, respectively and fit the Linear and Weibull Models. Applying 0.05 to 0.18% of H₂O₂-PAA reduced L. monocytogenes by 2.03 to 3.32 log₁₀MPN/g and transferred cross-contaminated cell counts by 2.36 to 3.17 log₁₀MPN/g, with no differences (P > 0.05) compared to the water only treatment. Results suggested that applying allowable concentrations (0.08 to 0.15%) of H₂O₂-PAA during triple-wash does not show promising anti-Listeria activity on peppers. Future studies are needed to determine the minimum concentrations of the H₂O₂- PAA-mixer required to effectively reduce and mitigate microbial cross-contamination of Listeria monocytogenes on peppers.

Recommended Citation

Foster, Peighton Denae, "Anti-Listeria of H2O2-Peroxyacetic acid Anti-Listeria Efficacy of a Hydrogen Peroxide-Peroxyacetic acid Mixer in Bacterial Buffered Solution and on Bell Peppers" (2024). Graduate Theses, Dissertations, and Problem Reports. 12335.
https://researchrepository.wvu.edu/etd/12335