Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 3, 2003
Publication Date: February 1, 2009
Citation: Jacob, R., Porto Fett, A.C., Call, J.E., Luchansky, J.B. 2009. Fate of surface inoculated Escherichia coli O157:H7, Listeria monocytogenes and Salmonella Typhimurium on kippered beef during extended storage at refrigeration and abusive temperatures. Journal of Food Protection. 72:403-407. Interpretive Summary: Ready-to-eat (RTE) dried meats have been associated with food borne bacterial illnesses as well as with several voluntary and obligatory recalls in the United States. The presence of pathogen in RTE dried meat products is not desired and as such the manufacture of such products is strictly regulated in the United States. Therefore, we evaluated the fate of foodborne bacterial pathogens, such as Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium (about 100 thousand bacteria each) on the surface of kippered beef, a cured, dry product that is similar to beef jerky. Storage of the product for 28 days at 21 degree Celsius and for 7 days at 30 degree Celsius resulted in a reduction of greater or equal to 1,000 cells for all three pathogens tested. As expected, the higher the storage temperature, the greater the levels of inactivation for all three pathogens on the surface of kippered beef. These data substantiate that kippered beef does not provide a favorable environment for outgrowth/survival of Listeria monocytogenes, Salmonella typhimurium, or Escherichia coli O157:H7 that may be present on the surface of kippered beef due to post-process contamination.
Technical Abstract: The behavior of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium was evaluated on kippered beef. Individual pieces of the product were separately inoculated on the top and bottom surfaces with each 3- to 5-strain pathogen cocktail at ca. 6.0 log10 CFU/piece and stored at 4 degree, 10 degree, 21 degree, or 30 degree Celsius for up 28 days in each of two trials. Depending on storage temperature, pathogens numbers decreased ca. 0.4 to greater than or equal to 5.25 log10 CFU/piece. Storage of kippered beef surface inoculated with E. coli O157:H7, S. Typhimurium, and L. monocytogenes at 4 degree to 30 degree Celsius for 28 days generated average D-values of ca. 41 to 4.6, 40.8 to 5.3, and 29.5 to 4.3 days, respectively. As expected, the higher the storage temperature, the greater the level and rate of inactivation for all three pathogens. Also, storage of the product for 28 days at 21oC and for 7 days at 30'C resulted in a reduction greater than or equal to 3.0 log10 CFU per piece of all three pathogens. These data establish that kippered beef does not provide an environment conducive to pathogen proliferation.