A critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range

Some facts concerning the effect of non-equilibrium situations and glass transitions on the water activity (Aw) values of foods in the microbiological growth range are reviewed. Analysis of literature data suggests that although some amorphous intermediate moisture foods are non-equilibrium systems...

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Autores principales: Chirife, J., Buera, M.P.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_02608774_v25_n4_p531_Chirife
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spelling todo:paper_02608774_v25_n4_p531_Chirife2023-10-03T15:12:04Z A critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range Chirife, J. Buera, M.P. Some facts concerning the effect of non-equilibrium situations and glass transitions on the water activity (Aw) values of foods in the microbiological growth range are reviewed. Analysis of literature data suggests that although some amorphous intermediate moisture foods are non-equilibrium systems (e.g. very slow rate of attainment of equilibrium), the 'stability' (time dependency) of measured water sorption isotherms, or the prediction of water activity from equilibrium data corresponding to aqueous solutions of main food solutes (NaCl, sugars), are little affected. However, crystallization of amorphous components (sugars), which is also a consequence of non-equilibrium situations, may lead to significant modifications of Aw values in foods. As far as the prediction of microbial growth in foods is concerned, changes in non-equilibrium semi-moist foods may be in many situations slow (within the time frame of the food shelf-life) and/or so small that they do not seriously affect the application of Aw concept as a predictor of microbial growth. However, the use of Aw should always consider the possible influence of some non-equilibrium situations. © 1995. Fil:Buera, M.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_02608774_v25_n4_p531_Chirife
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description Some facts concerning the effect of non-equilibrium situations and glass transitions on the water activity (Aw) values of foods in the microbiological growth range are reviewed. Analysis of literature data suggests that although some amorphous intermediate moisture foods are non-equilibrium systems (e.g. very slow rate of attainment of equilibrium), the 'stability' (time dependency) of measured water sorption isotherms, or the prediction of water activity from equilibrium data corresponding to aqueous solutions of main food solutes (NaCl, sugars), are little affected. However, crystallization of amorphous components (sugars), which is also a consequence of non-equilibrium situations, may lead to significant modifications of Aw values in foods. As far as the prediction of microbial growth in foods is concerned, changes in non-equilibrium semi-moist foods may be in many situations slow (within the time frame of the food shelf-life) and/or so small that they do not seriously affect the application of Aw concept as a predictor of microbial growth. However, the use of Aw should always consider the possible influence of some non-equilibrium situations. © 1995.
format JOUR
author Chirife, J.
Buera, M.P.
spellingShingle Chirife, J.
Buera, M.P.
A critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range
author_facet Chirife, J.
Buera, M.P.
author_sort Chirife, J.
title A critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range
title_short A critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range
title_full A critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range
title_fullStr A critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range
title_full_unstemmed A critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range
title_sort critical review of some non-equilibrium situations and glass transitions on water activity values of foods in the microbiological growth range
url http://hdl.handle.net/20.500.12110/paper_02608774_v25_n4_p531_Chirife
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