A methodology to estimate the thermal conductivity (kappa) and volumetric thermal capacity (rhoc(p)) of apples is described. The methodology is based in the inverse problem of heat conduction solution. The apples are considered as spherical objects. This approach relies on an analytical solution of the problem and on an optimization technique to estimate the two thermophysical properties. Typically, a test to measures the temperature response of a specimen subjected to transient heating by hot air to determine the properties directly as a function of temperature. (C) 2004 Elsevier Ltd. All rights reserved.