Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 4/1/2005
Publication Date: 8/1/2005
Citation: Luchansky, J.B., Call, J.E., Phebus, R.K., Thippareddi, H. 2005. Blade-tenderization of beef subprimals inoculated with Escherichia coli O157:H7. International Association for Food Protection. Abstract. Paper # P-15. Interpretive Summary:
Technical Abstract: We evaluated the penetration of Escherichia coli O157:H7 (ECOH), surface inoculated on beef subprimals at ca. 0.6 to 3 log10 CFU/cm2, and tenderized with a single pass through a mechanical blade-tenderizer from the lean-side surface. A second set of inoculated subprimals were not tenderized (positive controls). Ten core samples were removed from each tenderized subprimal and cut into six consecutive segments starting from the inoculated side: segments 1 to 4 represent the top four cm of the core and segments 5 and 6 represent the deepest four cm. Ten cores were obtained from control subprimals but only segment 1 was sampled. Each segment was weighed, diluted, and blended. The slurry was plated onto Sorbitol-MacConkey agar plates. Data for two trials at each inoculum level were averaged. The levels of ECOH recovered from segment 1 of control subprimals were 0.6, 1.46, 2.44, and 3.15 log10 CFU/cm2, respectively. The extent of penetration of the pathogen into Segment 1 of the tenderized subprimals at these four inoculum levels was 0.22, 1.06, 2.04, and 2.7 log10 CFU/g, respectively. The levels recovered in Segment 2 were at least seven-fold lower than levels in Segment 1; however, depending on the inoculum level, it was possible to recover ECOH from all six segments. These results demonstrate that mechanical tenderization can transfer ECOH into the interior of a subprimal, most (ca. 40%) of which remains in the top segment.