Thermal properties are very important to simulate heat transfer during heat treatment of foods. The aim of this work was to study heat transfer aspects of the mortadella cooking process and the use of actual temperature transient profiles to estimate the effective thermal diffusivity (alpha). The Ball and Olson equation was used to determine alpha behavior during the cooking process, wherein it was verified that, alpha increases twofold after protein denaturation, at close to 70 degreesC. Another objective was to verify the ability of a conduction heat transfer model to predict the heat penetration curve. The results showed that it is possible to estimate the effective thermal diffusivity using experimental temperature history and the heat conduction model, even for time-varying boundary conditions. (C) 2002 Elsevier Science Ltd. All rights reserved.