Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 3/2/2011
Publication Date: 8/1/2011
Citation: Luchansky, J.B., Porto-Fett, A., Shoyer, B.A., Call, J., Chen, V., Kause, J., Eblen, D., Cook, V., Mohr, T., Esteban, E., Bauer, N. 2011. Thermal inactivation of Escherichia coli O157:H7 (ECOH) in frozen ground beef patties following cooking on commerical open-flame gas and electric clam-shell grills. International Association for Food Protection Annual Meeting, July 31-August 3, 2011, Milwaukee, Wisconsin., Poster No. P1-56. p. 77. Interpretive Summary:
Technical Abstract: Both the prevalence and levels of serotype O157:H7 strains of Escherichia coli (ECOH) are quite low, yet this pathogen continues to cause food borne illness due to consumption of undercooked ground/non-intact beef. Thus, further studies are warranted to comparatively quantify thermal destruction of ECOH in refrigerated versus frozen ground beef patties. Both high fat and low fat ground beef (percent lean:fat = 70:30 and 93:7, respectively) were purchased from a local butcher and inoculated with a 5-strain cocktail of ECOH (ca. 7.0 CFU/g). Patties were pressed (ca. 2.54 cm thick, ca. 300 grams) and then either refrigerated (4 deg C, 18 hours) or frozen (-20 deg C, 3 weeks) before being cooked on a commercial open-flame gas grill or on a clam-shell electric grill to internal temperatures of 60 deg to 76.6 deg C. Regardless of the type of grill, cooking low and high fat refrigerated patties to 71.1 deg or 76.6 deg C decreased ECOH numbers from ca. 7.2 log CFU/g to =0.9 log CFU/g, whereas decreases from ca. 7.2 log CFU/g to ca. 1.0 to 3.0 log CFU/g in pathogen numbers were observed when refrigerated patties were cooked at 60.0 deg or 65.5 deg C. For low and high fat frozen patties that were cooked to 71.1 deg or 76.6 deg C, ECOH numbers decreased from ca. 6.7 log CFU/g to ca. 0.6 to 1.5 log CFU/g. Likewise, pathogen numbers decreased from ca. 6.7 log CFU/g to ca. 1.7 to 3.3 log CFU/g when frozen patties were cooked to 60.0 deg or 65.5 deg C. These results validated that cooking refrigerated and frozen ground beef patties to an internal temperature of greater than or equal to 71.1 deg C is effective for destroying ECOH and, in turn, lessening the threat of illness associated with this food borne pathogen.