VALIDATION OF THE EFFECT OF INTERVENTIONS AND PROCESSES ON PERSISTENCE OF PATHOGENS ON FOODS
Location: Food Safety and Intervention Technologies
Title: Fate of Escherichia coli O157:H7 (ECOH) in blade tenderized beef prime rib following searing, cooking and holding under commercial conditions
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 8, 2011
Publication Date: August 1, 2011
Citation: Porto-Fett, A., Shoyer, B.A., Thippareddi, H., Luchansky, J.B. 2011. Fate of Escherichia coli O157:H7 (ECOH) in blade tenderized beef prime rib following searing, cooking and holding under commercial conditionsm [abstract]. International Association for Food Protection Annual Meeting, July 31-August 3, 2011, Milwaukee, Wisconsin. Poster No. 1-60. p. 79.
Undercooked non-intact beef has caused a number of illnesses due to contamination with serotype O157:H7 strains of Escherichia coli (ECOH). Few studies have quantified translocation and/or thermal inactivation of ECOH directly in blade tenderized beef. There have been no such studies for prime rib, yet this product may pose a greater risk to public health than others because it is cooked/held for extended times at lower temperatures.
Evaluate the effect commercial searing, cooking, and holding times/temperatures for elimination of ECOH from tenderized beef prime rib.
Boneless prime rib was inoculated on the fat side with ca. 6.0 log CFU/g of a five-strain cocktail of ECOH and then passed once through a blade tenderizer with the fat side facing upwards. The tenderized prime rib was seared at 500 deg F for 30 min in a conventional (home) oven and then cooked in a commercial convection oven at 250 deg F to internal temperatures of 100 deg, 120 deg, 140 deg, and 160 deg F before being placed in a commercial holding oven (140 deg F) for up to 8 hours.
After searing, ECOH numbers decreased by ca. 1.2 log CFU/g. Following cooking to 100 deg F pathogen numbers decreased by an additional ca. 1.3 log CFU/g, whereas cooking to internal temperatures of 120 deg, 140 deg, and 160 deg F resulted in an additional decrease of ca. =2.4 log CFU/g. After cooking to 100 deg F and then holding at 140 deg F for 8 hours, pathogen numbers increased by an additional ca. 1.3 log CFU/g. In contrast, after cooking to 120 deg, 140 deg, or 160 deg F and holding for up to 8 hours at 140 deg F, ECOH numbers remained relatively unchanged.
The commercial practices for searing, cooking, and holding prime rib evaluated herein are effective for reducing levels of ECOH that may exist within the deeper tissues of the meat due to blade tenderization if the product is cooked to temperatures >120 deg F.