To develop and implement technologies to encourage food product development in retortable pouches.

1.- To develop a predictive model, which allows to estimate internal pressure in the head space of flexible packages subjected to thermal processes. Energy balance based on the first law of thermodynamic will be used. 2.- To calibrate the model through experiments carried out in a controlled system with a model food. 3.- To validate the model by using model foods with known aw, packaged in retortable pouches and processed in a retort with overpressure. 4.- To experimentally validate Patel´s model (Patel et al. 1991) to be useful in a wider range of foods (different aw).