Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/5/2014
Publication Date: 8/6/2014
Citation: Swartz, R., Kulas, M., Shane, L., Strasser, H., Munson, M., Shoyer, B.A., Luchansky, J.B., Porto Fett, A.C. 2014. Thermal inactivation of Shiga toxin-producing Escherichia coli 0157:H7 in cubed beef steaks following cooking on an electric skillet. Abstracts of the Annual Meeting of International Association for Food Protection. Volume 1, Page 1. Indianapolis, Indiana. Interpretive Summary:
Technical Abstract: Cubed steak is an eye round steak that has been mechanically tenderized to make it more desirable for the consumer. Since it is a non-intact product, it should be cooked like ground beef due to possible translocation of bacteria into the deeper tissues of the meat as a result of the tenderization process. However, no studies have addressed the viability of Shiga toxin-producing Escherichia coli (STEC) in non-intact beef processed via mechanical cubing. For these reasons, we quantified the thermal inactivation of STEC within knitted/cubed steak following cooking on an electric skillet. For each of three trials, commercially-processed eye round steaks (ca. 114 g; ca. 1.5 cm thick) were surface inoculated (ca. 6.6 log CFU/g) with a rifampicin-resistant cocktail comprised of single strains from each of eight target serogroups of STEC (STEC-8; O111:H-, O45:H2, O103:H2, O104:H4, O121:H19, O145:NM, O26:H11, and O157:H7). Next, inoculated steaks were passed once through a mechanical tenderizer, and then two tenderized steaks were knitted together by passing them concomitantly through the tenderizer two additional times. Following tenderization, knitted/cubed steaks were individually cooked on a flat-surface electric skillet set at ca. 191.5 degrees Celsius for up to 3.5 minutes per side. The longer the cooking time, the higher the final internal temperature, and the greater the inactivation of STEC within cubed steaks. The average final internal temperature of knitted/cubed steaks cooked for 1.0 to 3.5 minutes ranged from 40.3 to 82.2 degrees Celsius. Cooking cubed steaks on an electric skillet set at ca. 191.5 degrees Celsius for 1.0, 1.5, 1.75, 2.0, 2.5, 3.0, and 3.5 minutes per side resulted in average total reductions of ca. 1.0, 2.1, 2.2, 2.8, 4.1, 5.2, and 6.3 log CFU/g in pathogen numbers, respectively. These data validated that cooking cubed steaks on an electric skillet at 191.5 degrees Celsius for at least 3 minutes per side was sufficient to achieve a 5.0-log reduction of STEC-8.