VALIDATION OF THE EFFECT OF INTERVENTIONS AND PROCESSES ON PERSISTENCE OF PATHOGENS ON FOODS
Location: Food Safety and Intervention Technologies
Title: Fate of Listeria monocytogenes inoculated onto the surface of soudjouk and kippered beef and stored at different temperatures
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 29, 2007
Publication Date: July 8, 2008
Citation: Jacob, R., Porto Fett, A.C., Call, J.E., Hwang, C., Luchansky, J.B. 2008. Fate of Listeria monocytogenes inoculated onto the surface of soudjouk and kippered beef and stored at different temperatures. Meeting Abstract. P2-45.
We evaluated the viability of Listeria monocytogenes on two ready-to-eat (RTE) specialty/ethnic meat products, namely soudjouk and kippered beef, during storage at different temperatures. Individual slices (1.5cm L x 2.0 cm W x 0.8 H) of these two products were separately inoculated on both the top and bottom surfaces with a five-strain cocktail of L. monocytogenes (6.0 log10 CFU/slice). Each slice was re-packaged in polyethylene sterile sampling bags that were then vacuum sealed and stored at 4, 10, 21, or 30 degree C for up 28 days. In each of 2 trials, 3 slices were tested on days 0.25, 1, 2, 3, 5, 7, 10, 13, 17, 21, 28 for each storage temperature. For soudjouk, levels of L. monocytogenes decreased by at least 5.0 log10 CFU/slice to below detection (0.7 log10CFU/slice) by direct plating after 5, 13, and 26 days when stored at 30, 21, and 10 degree C, respectively, whereas at 4 degree C pathogen levels decreased by about 3.0 log10CFU/slice after 28 days. For kippered beef, pathogen numbers decreased to below detection within 10 days at 30 degree C, whereas when the product was stored at 21, 10, or 4 degree C, pathogen numbers decreased by 5.0, 2.0, and 1.0 log10CFU/slice, respectively, within 28 days. These data confirm that pathogen numbers decreased appreciably during storage of both products as the storage temperature increased and did so without appreciably affecting the general product quality or texture. These data also substantiate that kippered beef and soudjouk do not provide a favorable environment for subsequent growth of L. monocytogenes that may be present on the surface of these products due to post-process contamination.