Inverse determination of the specific heat of foods Original Research Article

Simulation of heat conduction processes in foods requires a knowledge of the temperature dependence of their thermal properties, conductivity (k) and specific heat (ce). In this work a new procedure is proposed for the inverse estimation of ce in a 1-D solid under convective and adiabatic boundary conditions, in which conductivity is constant or temperature-dependent. The inverse problem is treated as a function estimation problem so that no prior information is needed about the form of the dependence. The estimation is obtained by means of a piece-wise function, whose stretches (both slope and size) is continuously adjusted by an iterative routine that minimizes the classical functional for this kind of problems. This routine is combined with the Network simulation method as the numerical technique. The input data of this inverse problem are obtained from the solution of the direct problem, at a particular location in the food, modified by a normal distribution random error. Applications to real products are realized proving that it is possible to reach precise estimations of ce with the proposed method.