Use of End Point Internal Product Temperature to Control Histamine Formation in Tuna at Pre-cooking Step

Alinear heating and cooling model was developed to determine a critical limit for precooking End Point Internal Product Temperature (EPIPT) in order to achieve a 5-log reduction of the most prolific histamine-forming bacterium, (HFB) Morganella morganii. The thermal death time values used in a General Method calculation employed the Trapezoidal rule, where D60˚C of 0.26m and z = 4.1˚C. Based on the thermal death time values and the General Method calculations, a 60°C pre-cooking EPIPT for tuna of any size will stop histamine formation during and after pre-cooking, until the de-skinning step is reached, thus providing the canned tuna industry with significant extra time to process tuna, especially with the larger sizes. It is also possible to use process lethality as a tool to evaluate a deviation from the process schedule, where a 5-log reduction of HFB can be demonstrated for a pre-cook batch. This information should be of interest to the tuna processing industry and regulatory officials interested in controlling histamine production in these products.