High-Pressure Phase Equilibrium Methodologies Applied to Food Systems

In addition to new methods to produce safe, healthy and shelf-stable products, food industries aim to recover valuable products or to separate undesirable compounds from natural food matrices. One possible alternative to achieve this goal is to apply high-pressure technologies such as supercritical fluid extraction (SFE), pressurized liquid extraction etc. Phase equilibrium and thermodynamic properties of food systems as well as transport properties, such as viscosity, thermal conductivity, or diffusivity, are important parameters for the food industry. In the design and operation of such high-pressure technological processes, a large amount of reliable data on the equilibrium properties of materials is necessary, for instance, in the case of SFE the separation step in entirely depended on the phase equilibria of the extract and the supercritical fluid. Experimental techniques for high-pressure phase equilibrium measurements of substances relevant to the food industry are summarized in this review in terms of the advantages, disadvantages and common applications of the methods.