High-Pressure Sterilization: Maximizing the Benefits of Adiabatic Heating

WOUTER B.C. DE HEIJ, LUDO J.M.M. VAN SCHEPDAEL, ROY MOEZELAAR, HANS HOOGLAND, ARIETTE M. MATSER,

ROBERT W. VAN DEN BERG

March 1, 2003

When a product is pressurized, an adiabatic temperature increase always occurs as a result of compression heating. However, most researchers working to develop high-pressure sterilization processes have not taken full advantage of that phenomenon.

This article describes an approach that maximizes the benefits of adiabatic heating and thereby increases enormously the feasibility of high-pressure sterilization of foods. It reports on the importance of temperature control during high-pressure steril…

Table 1—Temperature changes of selected substances due to compression heating.

Fig. 2—Laboratory-scale prototype of a high-pressure sterilization system which maximizes the benefits of the adiabatic increase in product temperature resulting from compression heating.

High-Pressure Sterilization: Maximizing the Benefits of Adiabatic Heating

Fig. 3—Reaction rate k in sec–1 (expressed as its natural logarithm) and decimal reduction rate D (expressed in min) of high-pressure inactivation of spores of B. stearothermophilus ATCC 7953 as a function of the applied pressure at various final product temperatures.

Fig. 4—Simulation of high-pressure inactivation of spores of B. stearothermophilus ATCC 7953 in a system without (left) and with (right) a product container. Upper panel shows the pressure profile; middle panel shows the temperature profiles in the center (red line) and near the wall (blue line) of the vessel; and lower panel shows viable spore count.