Date of Award

Spring 5-2026

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Food Science

First Advisor

Dr Rosalee Hellberg

Second Advisor

Dr Thuy Xuan Uyen Phan

Third Advisor

Dr Anuradha Prakash

Abstract

Listeria monocytogenes is one of the major foodborne illness-causing pathogens in the United States, resulting in an average of 1600 cases per year with a 94% hospitalization rate according to the CDC. The Contamination Sanitization Inspection and Disinfection (CSI-D+) device is a UVC emitting handheld system that represents a novel approach to the detection and disinfection of microorganisms on food contact surfaces. This study aims to evaluate the disinfection module of the CSI-D+ device for L. monocytogenes within food residue on food contact surfaces, primarily associated with food processing. The food contact surfaces tested included stainless steel 304, and polyethylene. Raw salmon juice was inoculated with L. monocytogenes serotypes 1/2a, 1/2b, and 4b on the food contact surfaces and then exposed to the 275 nm wavelength of the CSI-D+ disinfection module for 30 and 45 s. The average L. monocytogenes percent reduction for all serotypes, surfaces, and time combinations was 49.6% with all log reductions ranging from 0.2 and 0.4 log CFU/ml. The highest reduction of L. monocytogenes was 57.7% (0.4 log CFU/ml) for strain 1/2b on polyethylene food contact surface for 45 s. An interaction effect was found for 1/2a and 1/2b serotypes on the polyethylene surface. The results of this study suggest that the device has potential to serve as a preventative measure in reducing outbreaks and recalls in food industries within the United States; however, more research is needed to determine the optimal device parameters.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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Available for download on Friday, March 10, 2028

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