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Evidence for the osmotic dehydration theory of freeze damage
Author(s) -
Grieve Peter W.,
Povey Malcolm J. W.
Publication year - 1981
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740320114
Subject(s) - membrane , dilution , sucrose , chemistry , cellulose acetate , osmosis , chromatography , polyethylene glycol , dehydration , osmotic pressure , biophysics , biochemistry , thermodynamics , biology , physics
Current views on freeze damage require that a reversal of osmotic flow occurs, on differential freezing across a membrane. This hypothesis has been tested using a variation of the traditional thistle‐funnel apparatus. Cellulose acetate membranes were used to retain sucrose solution within the thistle‐funnel and the arrangement was immersed in water. The sucrose concentration was measured refractrometrically whilst the water was slowly frozen. Once the water had fully frozen the sucrose concentration was observed to increase, reversing the steady dilution that had been observed before freezing of the water was complete. This concentration effect is consistent with a reversal of osmotic flow on differential freezing across the membrane. The effect was also observed in polyethylene glycol, retained with Amicon diaflo UMOS membranes.