High pressure freezing and thawing of foods: a review

The phase diagram of water shows that the melting temperature of water decreases with pressure down to -21degreesC at 210 MPa while the opposite effect is observed above this pressure. This phenomenon allows the achievement of rapid freezing and thawing of foods that mainly contain water. In addition, pressure-assisted thawing has the advantage of inducing a reduction in drip loss which tends to be a function of process parameters and nature of the product. Concerning pressure shift freezing, this process permits the significant preservation of the microstructure of biological substances. The current status of high pressure freezing and thawing applications in foods is reviewed in this paper. Concepts and principles underlying the application of these technologies are firstly developed. Available literature on the applications of high pressure freezing and thawing is then presented and discussed. Finally, the modelling aspects of theses processes are dealt with. (C) 2002 Elsevier Science Ltd and IIR. All rights reserved.