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Metastable States of Water and Ice during Pressure‐Supported Freezing of Potato Tissue
Author(s) -
Schlüter O.,
Benet G. Urrutia,
Heinz V.,
Knorr D.
Publication year - 2004
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp0340279
Subject(s) - supercooling , metastability , clear ice , thermodynamics , atmospheric pressure , ice nucleus , congelation , nucleation , chemistry , ice crystals , phase transition , ambient pressure , phase (matter) , materials science , meteorology , geology , arctic ice pack , climatology , sea ice , organic chemistry , physics , antarctic sea ice
Different ice modifications were obtained during freezing processes at several pressure levels from atmospheric pressure up to 300 MPa. In the pressure range between 210 and 240 MPa, a metastable ice I modification area was observed, as the nucleation of ice I crystals in the thermodynamically stable region of ice III was reached. A significant degree of supercooling was obtained before freezing the tissue water to ice III, which has to be considered when designing pressure‐supported freezing processes. The effect of supercooling phenomenon on the phase transition time is discussed using a mathematical model based on the solution of the heat transfer governing differential equations. Phase transition and freezing times for the different freezing paths experimented are compared for the processes: freezing at atmospheric pressure, pressure‐assisted freezing, and pressure‐shift freezing. Different metastable states of liquid water are defined according to their process‐dependent stability.