Project Number: 1935-41420-015-05
Project Type: Reimbursable

Start Date: Feb 01, 2010
End Date: Sep 30, 2010

Objective:
Quantify the effect of freezing, thawing, and/or subsequent cooking on the fate of Escherichia coli O157:H7 (ECOH) and other non-verocytotoxigenic E. coli (STEC) in ground beef patties.

Approach:
Ground beef will be purchased from a local retailer, inoculated with a five-strain cocktail of pathogenic E. coli, formed into patties, and held frozen for up to 3 months. The patties will be cooked, with and without prior thawing, on commercial grills and pathogen viability will be quantified. Parameters to be evaluated will include the fat content of ground beef, serotype of E. coli, freezing duration and thawing regimen for patties, cooking temperature, and grill type as detailed in Appendix A. The experimental design was derived from multiple conversations between key players from both FSIS and ARS. Ongoing discussions between ARS and FSIS as to the nature, number, and scope of the project may necessitate that the timeframe for completion be extended and/or the cost be increased.