Both freeze-concentration and high pressure treatments are promising technologies that can be combined in order
to improve juice quality and increase shelf life.Mathematicalmodeling is a useful tool to design, to develop and to
optimize these processes but it faces a lack of data on physical properties of foods at high pressure. For that reason,
the volumetric properties of orange juice and concentrates (12 to 40 °Brix) were determined at temperatures between−
20 °C and+40 °C and pressures up to 350MPa. A variable volumepiezometerwas used for that purpose.
The coefficients of an equation of state initially developed for waterwere fitted to allowfor calculating the specific
volume as a function of pressure and temperature. The isothermal compressibility and the thermal expansion
coefficients calculated from the resulting equation of state show similar behaviors as those of water with some
subtle differences. Temperatures of specific volume and compressibility coefficients minima are shifted toward
lower values than those of water as solutes concentration increases. Volumetric properties progressively tend to
behave as those of a solid. Any use ofwater properties to approximate orange juice concentrate properties behavior
under pressure gives rise to significant uncertainties when calculating adiabatic heat. Studies about the sensitivity
of models to each property and to their respective uncertainty would help in pointing out experimental
needs and accuracy requirements for the determination of food thermophysical properties at high pressure.
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