Development and validation of a mathematical model for HTST processing of foods containing large particles

A mathematical treatment for a heat penetration phenomenon with variable boundary conditions is presented. The system of differential equations for determining the unsteady-state temperature distribution inside a particle was solved by use of spectral methods as a new tool in food process development. A preliminary study was conducted on the use of a mathematical model to predict lethality in a sterilizing process. The model was validated using a calibrated time-temperature integrator (TTI) with immobilized Bacillus stearothermophilus spores, commonly used in TTIs for process validation. A comparison between the experimental data using Bacillus stearothermophilus and the predicted data obtained with the proposed model showed good agreement.