Escherichia coli O157:H7 risk assessment for blade-tenderized beef steaks

Abstract

The potential translocation of E. coli O157:H7 from the surface to the interior of whole muscle by blade tenderization was evaluated. Beef top sirloin subprimals were inoculated with 106 or 103 cfu/cm2 and passed once through a Ross blade tenderization unit. Core samples showed a translocation of 3 to 4% of surface inoculum to the geometric center of the subprimal. A second study evaluated thermal destruction of E. coli O157:H7 in blade tenderized (BT) steaks compared to nontenderized (NT) steaks of three thicknesses when ovenbroiled. Subprimal surfaces were inoculated to a level of 107 cfu/cm2 and blade tenderized. Steaks cut from these subprimals were ovenbroiled to internal temperatures from 120 to 170°F, then analyzed for surviving E. coli O157:H7. At internal steak temperatures of 140°F and higher, all E. coli O157:H7 were killed in both BT and NT steaks of all thicknesses. At 130°F, about 5 log reductions were noted for both BT and NT. With oven broiling to even moderate internal temperatures, BT steaks pose no greater risk of E. coli O157:H7 infection than NT steaks.