Recovery of Shiga Toxin-producing Escherichia coli in Tenderized Veal Cordon Bleu Following Cooking on an Electric Skillet

Introduction: The implication of veal products in several recalls due to contamination with Shiga toxin-producing Escherichia coli (STEC) and USDA FSIS verification sampling results revealing a higher percent positive rate of STEC in veal than in beef products provides justification for validating cooking practices for preparing veal products, particularly those processed via mechanical tenderization. 

Purpose: Evaluate the viability of STEC in tenderized cordon bleu veal cooked on a flat-surface electric skillet. 

Methods: Veal cutlets (ca. 75 g; ca. 0.34 cm thick) were surface inoculated with ca. 6.6 log CFU/g of a rifampicin-resistant, eight-strain cocktail of STEC (STEC-8; O111:H-, O45:H2, O103:H2, O104:H4, O121:H19, O145:NM, O26:H11, and O157:H7). Following inoculation, cutlets were mechanically tenderized via single passage through a “Sir Steak” tenderizer. Next, cordon bleu cutlets were prepared by laying one slice of ham and one slice of Swiss cheese between two tenderized cutlets, and then coating the cutlets with pre-sifted flour, liquid whole eggs, and flavored bread crumbs. For each of three trials, three inoculated and tenderized cutlets were individually cooked on a pre-heated skillet (ca. 191.5°C) for 4 to 10 min per side.

Results: Cooking tenderized veal cordon bleu on a pre-heated skillet for 4, 5, or 6 min reduced STEC levels by ca. 1.2, 2.5, and 3.0 log CFU/g, respectively. However, cooking cutlets for 7, 8, 9, or 10 min resulted in reductions of ca. 6.0 to 6.2 log CFU/g.

Significance: These data validate that cooking tenderized veal cordon bleu for at least 7 min per side on an electric skillet set at ca. 191.5°C is sufficient to achieve a ≥5-log reduction of STEC and, in turn, to appreciably lower the likelihood of illness if cutlets are contaminated with this pathogen.