title: The influence of beef quality characteristics on the internalization and thermal susceptibility of Shiga toxin-producing Escherichia coli (STEC) in blade-tenderized beef steaks.
abstract: The risk of Shiga toxin-producing Escherichia coli (STEC) survival in blade-tenderized beef is a concern for beef processors. This study evaluated the internalization and post-cooking survival of individual STEC serogroups (O157:H7, O26, O45, O103, O111, O121, and O145) in blade-tenderized beef steaks with different quality traits. Strip loins representing four combinations of USDA Quality Grade (Choice or Select) and pH category (High pH or Normal pH) were inoculated (10(6)logCFU/cm(2) attachment) with individual STEC serogroups before storage (14 days), blade tenderization, and cooking (50, 60, 71, or 85°C). Serogroup populations on raw steak surfaces and internal cores were determined. Rapid-based methods were used to detect the internal presence of STEC in cooked steaks. Internalization and post-cooking survival varied among STECs. All serogroups, except O45 and O121, were detected in the internal cores of steaks cooked to 50°C, while O103, O111, and O145 STEC were detected in steaks cooked to 50, 60, and 71°C.
authors.affiliation: Texas Tech University, Department of Animal and Food Sciences, Box 42141, Lubbock, TX 79409, USA.
authors.forename: B
authors.initials: B
authors.lastname: Corliss
authors.affiliation: Texas Tech University, Department of Animal and Food Sciences, Box 42141, Lubbock, TX 79409, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Brooks
authors.affiliation: Texas Tech University, Department of Animal and Food Sciences, Box 42141, Lubbock, TX 79409, USA.
authors.forename: J N
authors.initials: JN
authors.lastname: Martin
authors.affiliation: Texas Tech University, Department of Animal and Food Sciences, Box 42141, Lubbock, TX 79409, USA.
authors.forename: A
authors.initials: A
authors.lastname: Echeverry
authors.affiliation: Texas Tech University, Department of Animal and Food Sciences, Box 42141, Lubbock, TX 79409, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Parks
authors.affiliation: Texas Tech University, Department of Animal and Food Sciences, Box 42141, Lubbock, TX 79409, USA.
authors.forename: S
authors.initials: S
authors.lastname: Pokharel
authors.affiliation: Texas Tech University, Department of Animal and Food Sciences, Box 42141, Lubbock, TX 79409, USA. Electronic address: mindy.brashears@ttu.edu.
authors.forename: M M
authors.initials: MM
authors.lastname: Brashears
mesh_terms: D000818:Animals; D002417:Cattle; D003296:Cooking; D005516:Food Microbiology; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D000069466:Red Meat / Q000145:classification / Q000382:microbiology*; D065288:Serogroup; D054323:Shiga-Toxigenic Escherichia coli / Q000254:growth & development*
keywords: Beef; Blade tenderized; Cooking; Internalization; Non-intact; STEC