Changes in meat tenderness that occur during cooking are generally associated with heat-induced alterations of the components (collagen and myofibrillar proteins) of the primary structure of the muscle tissue. Heat transfer during the cooking process and the related textural changes were simulated numerically in irregular domains by integrating both the differential equation for unsteady state heat conduction and the temperature-dependent kinetic equation that corresponds to textural changes of the cooked meat. A code employing a boundary-fitted grid method was implemented in a numerically conservative form (control volume formulation). The proposed model was verified experimentally on irregularly shaped pieces of beef. The effects of heat transfer coefficient, temperature of the cooking medium, and size of the meat piece on the hardness distribution and average final hardness of the cooked product were studied. When the temperature of the cooking medium was above 85 degrees C the average hardness was always high, regardless of processing time, even for small pieces of meat. Conversely, low a more tender product, although on large beef cuts this advantage is overcome because of the long cooking times required.