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We believe that immunochemical measurement of TPI concentration in beef can be used to rapidly verify compliance to USDA processing schedules for beef products.<P>
Our objectives are to:
<ol>
<li> develop an immunoassay to quantify TPI in beef muscle; and, </li>
<li> verify that TPI can be used to determine compliance to the USDA cooking schedules for roast beef and beef patties in pilot and field studies. </li></ol>
<p>
The immunoassay will be evaluated by comparing TPI concentrations in adequately commercially-applicable conditions to establish a minimum concentration of TPI that indicates proper processing. It is envisioned that a user-friendly immunoassay can be developed to accurately and rapidly verify minimum processing temperatures of beef products to improve the safety of our food supply.</p>
<P>
Outbreaks of Escherichia coli 0157:H7, associated mainly with the consumption of undercooked ground beef patties, have led to an intensive review of methods used to ensure cooked meat product safety. Although thorough cooking can reduce the incidence of foodborne disease, it is not yet possible to verify "after the fact" that a product has been properly processed. </p>
<P>
We hypothesize that it is feasible to utilize endogenous muscle protein indicators to monitor thermal processing of beef products. In laboratory and pilot plant tests, we have found that the inactivation kinetics (specifically, the dependence of the inactivation rate on cooking temperature) of the endogenous beef muscle enzyme, triose phosphate isomerase (TPI), are similar to those of the microorganisms used to select the USDA beef processing schedules.</p>