Date of Award
Spring 5-2025
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Food Science
First Advisor
Dr Rosalee Hellberg
Second Advisor
Dr Anuradha Prakash
Third Advisor
Dr Thuy Xuan Uyen Phan
Abstract
Salmonella is the top bacterial cause of foodborne illness in the United States, with outbreaks commonly associated with poultry products. The Contamination Sanitization Inspection and Disinfection (CSI-D+) device is a handheld portable system equipped with fluorescence imaging with dual operations of detection and disinfection of microorganisms on food contact surfaces. The objective of this study was to assess the effectiveness of the disinfection module of the CSI-D+ device on Salmonella enterica in food residue (i.e., chicken juice) on food contact surfaces (FCS) commonly found in food processing environments. Raw chicken juice was inoculated with S. enterica serovar Enteritidis and added to the following food contact surfaces: stainless steel 304, polycarbonate, polyethylene, and polytetrafluoroethylene (PTFE). The inoculated food contact surfaces were exposed to low (5 mW/cm²) and high intensity (10 mW/cm²) UV-C at a wavelength (λ) of 275 nm using the CSI-D+ device for 15 and 30 s. The results showed that higher UV-C irradiance (10 mW/cm²) led to significantly higher S. enterica serovar Enteritidis log CFU/ml reductions across all tested food contact surfaces compared to lower irradiance (5 mW/cm²). The higher exposure time of 30 s yielded statistically significant improvements compared to the 15 s exposure time. Among the food contact surfaces, PTFE demonstrated a significantly higher reduction (0.52-1.00 log CFU/ml) in S. enterica following CSI-D+ treatment as compared to polycarbonate, which showed log reductions ranging from 0.50-0.97 log CFU/ml. A reduction in the range of 0.59-1.01 log CFU/ml was observed for the stainless steel surface. These findings suggest that the CSI-D+ device may be used in poultry processing facilities as an additional sanitization step to help control S. enterica on food contact surfaces.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Recommended Citation
Tirpude, G. (2025). Ultraviolet C inactivation of Salmonella enterica in raw chicken juice on food contact surfaces with the Contamination Sanitization Inspection and Disinfection (CSI-D+) device. Master's thesis, Chapman University. https://doi.org/10.36837/chapman.000690