To develop predictive models for 1) growth of Yersinia pestis (non-select agent) in raw ground beef, (2) thermal inactivation of Bacillus anthracis Sterne (non-select agent) in cooked ground beef, and (3) thermal inactivation of Y. pestis (non-select agent) in cooked ground beef.
Approach: Sterile (irradiated) raw ground beef will be inoculated with a single strain of Y. pestis. Growth kinetics will be measured over a range of temperatures that permits Y. pestis growth. Inactivation kinetics will be measured at a minimum of four temperatures to calculate D- and Z-values. The inactivation model will be validated with clam shell- and gas grill-types of commercial cooking equipment. The resulting growth and inactivation models will be translated into a spreadsheet interface.