Interest of high pressure calorimetry and conventional calorimetry for the study of high pressure processing

A. LEBAIL, S. ZHU, A. OUSEGUI, R. ZUNIGA, V. TIRONI, M. ANTON-DE LAMBALLERIE, M. HAYERT AND H.S. RAMASWAMY

Tsukuba, Japan

Conferencia; 4th International Conference on High Pressure Bioscience and Biotechnology (HPBB2006); 2006

This paper presents different application of high pressure processing to food. Sevral experimental techniques can be used to assess the effect of high pressure on food material. Among them, calorimetry can be a very useful tool. A first examples deals with the impact of high pressure processing on the temperature of glass transition of selected food samples. High pressure processing with or without freezing tends to increase the glass transition temperature of fish whereas no significant effect was observed for carrot and potato. This could be explained by a change in the water distribution in the matrix rich in proteins. A second example deals with the high pressure – low temperature applications. A high pressure calorimeter designed to work up to 400 MPa in the temperature range -20°C to 80°C has been designed to study ice-water transition under pressure. This calorimeter can work in temperature scan mode at constant pressure or in pressure scan mode at constant temperature. The calorimeter was calibrated with Joule effect setup and against the data of latent heat of pure water at high pressure (pressure range 50 – 180 MPa) proposed by Brigman. A comparison between pressure scan and temperature scan mode was done and demonstrated that better results were obtained at constant temperature. This calorimeter was then used to evaluate the latent heat of water in biological matrix such as a gel of methylcellulose (tylose), pork meat and fish meat. A model taking into account the dependence of the latent heat of the ice-water transition with pressure was developed and was compared with a good agreement to experimental data.