Modeling Thermophysical Properties of Food Under High Pressure

Abstract

A set of well-known generic models to predict the thermophysical properties of food from its composition at atmospheric conditions was adapted to work at any pressure. The suitability of the models was assessed using data from the literature for four different food products, namely tomato paste, potato, pork, and cod. When the composition of the product considered was not known, an alternative was proposed if some thermal data at atmospheric conditions were available. Since knowledge on the initial freezing point and ice content of food are essential for the correct prediction of its thermal properties, models for obtaining these properties under pressure were also included. Our results showed that good predictions under pressure, accurate enough for most engineering calculations can be made, either from composition data or using known thermal data of the food considered at atmospheric conditions. All the equations and coefficients needed to construct the models are given throughout the text, thus readers can compose their own routines. However, these routines can also be downloaded free at http://www.if.csic.es/programas/ifiform.htm as executable programs running in Windows.

Keywords:

• Ice fraction
• density
• specific heat
• thermal conductivity
• apparent specific heat
• enthalpy

ACKNOWLEDGEMENTS

This research was carried out with financial support from the Spanish “Plan Nacional de I+D+i (2004–2006) MCYT” through the AGL 2006-12112-C03-01 project. L. Otero was also partially supported by the “Ministerio de Ciencia y Tecnología” in Spain under a “Ramón y Cajal” research contract.