Food dehydration is one of a main process to preserve meal. In order to optimaze a freeze-drying operation a physic model is needed to well describe the thermodynamic behaviors involved in this process. In this work, a thermographic camera and different physico-chemical determinations are used to monitor many phenomena that occur during the lyophilization of poultry breast. Finally, a non-continuous irreversible thermodynamic model, based on thermal infrared measures and in shrinkage/swelling mechanism, has been developed, wich explains the behaviours produced throughout the meat freeze-drying process. Keywords: freeze-drying, thermodynamic model, infrared thermography, poultry.