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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #309539

Title: Use of a portable fluorescence imaging device to facilitate cleaning of deli slicers

item BECK, ELIZABETH - University Of Maryland
item Lefcourt, Alan
item Kim, Moon
item LO, MARTIN - University Of Maryland

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2015
Publication Date: 5/1/2015
Citation: Beck, E., Lefcourt, A.M., Kim, M.S., Lo, M. 2015. Use of a portable fluorescence imaging device to facilitate cleaning of deli slicers. Food Control. 51:256-262.

Interpretive Summary: Delis are the number one source of Lysteria monocytogenes infections (listerosis) in the USA. Although cases of listeriosis are relatively rare, the mortality rate is high (20%). Given the central role of the deli slicer in listeriosis, and the recognized deficiencies in established protocols to clean deli slicers, test were made to see if the use of a fluorescence imaging device could improve efforts to clean and sanitize slicers. A previous study demonstrated that residues from tested cheeses and processed meats could be detected using fluorescent imaging. A commercial slicer was scanned using the fluorescent imaging device after slicing a deli commodity, washing, and then again after sanitizing the slicer. Results demonstrated that the number of residues decreased with cleaning and sanitizing efforts. However, the slicer could not be fully cleaned without using the imaging device to direct cleaning efforts. These results will be of interest to the food industry and scientist working in the area of food safety. Results suggest that use of fluorescence imaging in delis should reduce the risk of foodborne illness in the general population due to listeriosis.

Technical Abstract: Cross-contamination is a recognized food safety concern for deli departments, and deli slicers remain a particular concern. Our laboratory previously demonstrated that deli commodity residues can be detected using fluorescence imaging, and that the efficacy of cleaning and sanitation in produce processing plants can be improved using a portable fluorescence imaging device. This study examines whether a fluorescence imaging device can improve the efficacy of procedures used to clean deli slicers. Blocks of American, Cheddar, Provolone, and Swiss cheeses and of processed chicken, ham, roast beef, and turkey were sliced using a commercial slicer. For each commodity, the slicer was scanned at 475, 520, and 675 nm after slicing five times, after washing, and after sanitation. Sets of hyperspectral images were acquired for detected problem areas. Most residues were found in three areas: around the blade and blade guard, on the surface where commodities were pressed during slicing, and on and around the spikes in the arm used to hold the commodities. Spectra of detected commodities were consistent with prior findings. The magnitude of residues detected decreased with cleaning and then sanitation; however, it was impossible to fully clean the slicer without using of the imagining device to direct cleaning efforts. The three wavelengths, 475, 520, and 675 nm, proved adequate to detect all deli residues. It is suggested that, upon availability, a commercial version of the imaging device be adopted for routine use in delicatessens.