Submitted to: Journal of Food Protection
Publication Type: Research Notes
Publication Acceptance Date: April 9, 2004
Publication Date: January 1, 2005
Citation: Sommers, C.H., Boyd, G. 2005. Elimination of listeria monocytogenes from ready-to-eat turkey and cheese tortilla wraps using ionizing radiation. Journal of Food Protection. 164-167. Technical Abstract: Listeria monocytogenes is a common post-process contaminant on ready-to-eat (RTE) foods including pre-made RTE sandwiches. One popular type of sandwich product is the tortilla 'wrap' which contains sliced luncheon meats and cheeses rolled within a flour tortilla. This study determined the radiation resistance of L. monocytogenes surface-inoculated onto two types of commercially available flour tortillas, processed cheese slices and deli turkey meat. The D-10 values for L. monocytogenes (the radiation dose required to inactivate 1 log 10 of the pathogen) was 0.27 kGy when inoculated onto two flour tortilla types, 0.28 and 0.3 kGy when inoculated onto two types of sliced processed cheeses, and 0.58 and 0.65 kGy when inoculated onto two types of sliced deli turkey meat. When two types of tortilla wraps were assembled from the individual components, and L. monocytogenes was inoculated into the interfaces between the individual components, the D-10 values were 0.27 to 0.37 kGy in the tortilla and cheese interfaces, 0.33 to 0.41 kGy in the cheese/turkey interfaces, and 0.25 to 0.33 kGy in the turkey/tortilla interfaces. The ability of ionizing radiation to reduce pathogen levels on the complex tortilla, cheese and luncheon meat product was limited by the higher radiation resistance of L. monocytogenes when inoculated onto the ready-to-eat turkey meat component.