Volumetric properties of sunflower and olive oils at temperatures between 15 and 55°C under pressures up to 350 MPa

Abstract

Numeric simulation is used to optimise the high pressure processing of foods. It allows for heat and mass transfer modelling and thus to address process uniformity problems. This modelling involves adiabatic heat, experimentally known to be higher for fats than for water, but hardly calculable due to the lack of data on food properties under pressure. In this work, the volumetric properties of sunflower and olive oils were determined to generate an original data set. A volumetric device working up to 350 MPa was assembled on the plug of high hydrostatic pressure equipment. The specific volume was measured as a function of pressure and temperature. An empirical equation of state was developed to derive the isothermal compressibility and thermal expansivity. Comparison with water properties shows how these results should contribute to improve the predictive skills of models used to simulate high pressure treatments of fat rich foods.