Thermal Stability of Dehydrated α-Amylase in Trehalose Matrices in Relation to its Phase Transitions

Thermal stability of α-amylase in trehalose matrices of reduced moisture content was studied as affected by phase transitions occurring as a result of increasing temperature at a moisture content of 50 g/kg. Removal of water greatly enhanced thermal stability of α-amylase but when trehalose was pres...

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Autores principales: Terebiznik, M.R., Buera, M.P., Pilosof, A.M.R.
Formato: JOUR
Materias:
α-amylase
Phase transitions
Stability
Trehalose
Arrhenius
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00236438_v30_n5_p513_Terebiznik
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00236438_v30_n5_p513_Terebiznik2023-10-03T14:34:01Z Thermal Stability of Dehydrated α-Amylase in Trehalose Matrices in Relation to its Phase Transitions Terebiznik, M.R. Buera, M.P. Pilosof, A.M.R. α-amylase Phase transitions Stability Trehalose Arrhenius Thermal stability of α-amylase in trehalose matrices of reduced moisture content was studied as affected by phase transitions occurring as a result of increasing temperature at a moisture content of 50 g/kg. Removal of water greatly enhanced thermal stability of α-amylase but when trehalose was present an extraordinary stabilization was achieved. Even in an initially rubbery condition, the protective effect of trehalose could be assessed up to 100 °C. Deactivation kinetics in the range 80-100 °C were related to crystallization of amorphous trehalose which would occur because the system was above the glass transition temperature. According to available water, at most 50% of amorphous trehalose would crystallize. The remaining amorphous trehalose phase would increase its glass transition temperature leading to enhanced enzyme stability. At temperatures close to 90 °C, trehalose dihydrate crystals start melting, releasing water which could promote further trehalose crystallization and enzyme deactivation. Once trehalose crystallizes, the protective effect may be lost since crystalline trehalose forms a separated phase no longer associated with the enzyme. These phase transitions were reflected as breaks in the Arrhenius plots. © 1997 Academic Press Limited. Fil:Terebiznik, M.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Buera, M.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Pilosof, A.M.R. 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_00236438_v30_n5_p513_Terebiznik
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic α-amylase
Phase transitions
Stability
Trehalose
Arrhenius
spellingShingle α-amylase
Phase transitions
Stability
Trehalose
Arrhenius
Terebiznik, M.R.
Buera, M.P.
Pilosof, A.M.R.
Thermal Stability of Dehydrated α-Amylase in Trehalose Matrices in Relation to its Phase Transitions
topic_facet α-amylase
Phase transitions
Stability
Trehalose
Arrhenius
description Thermal stability of α-amylase in trehalose matrices of reduced moisture content was studied as affected by phase transitions occurring as a result of increasing temperature at a moisture content of 50 g/kg. Removal of water greatly enhanced thermal stability of α-amylase but when trehalose was present an extraordinary stabilization was achieved. Even in an initially rubbery condition, the protective effect of trehalose could be assessed up to 100 °C. Deactivation kinetics in the range 80-100 °C were related to crystallization of amorphous trehalose which would occur because the system was above the glass transition temperature. According to available water, at most 50% of amorphous trehalose would crystallize. The remaining amorphous trehalose phase would increase its glass transition temperature leading to enhanced enzyme stability. At temperatures close to 90 °C, trehalose dihydrate crystals start melting, releasing water which could promote further trehalose crystallization and enzyme deactivation. Once trehalose crystallizes, the protective effect may be lost since crystalline trehalose forms a separated phase no longer associated with the enzyme. These phase transitions were reflected as breaks in the Arrhenius plots. © 1997 Academic Press Limited.
format JOUR
author Terebiznik, M.R.
Buera, M.P.
Pilosof, A.M.R.
author_facet Terebiznik, M.R.
Buera, M.P.
Pilosof, A.M.R.
author_sort Terebiznik, M.R.
title Thermal Stability of Dehydrated α-Amylase in Trehalose Matrices in Relation to its Phase Transitions
title_short Thermal Stability of Dehydrated α-Amylase in Trehalose Matrices in Relation to its Phase Transitions
title_full Thermal Stability of Dehydrated α-Amylase in Trehalose Matrices in Relation to its Phase Transitions
title_fullStr Thermal Stability of Dehydrated α-Amylase in Trehalose Matrices in Relation to its Phase Transitions
title_full_unstemmed Thermal Stability of Dehydrated α-Amylase in Trehalose Matrices in Relation to its Phase Transitions
title_sort thermal stability of dehydrated α-amylase in trehalose matrices in relation to its phase transitions
url http://hdl.handle.net/20.500.12110/paper_00236438_v30_n5_p513_Terebiznik
work_keys_str_mv AT terebiznikmr thermalstabilityofdehydratedaamylaseintrehalosematricesinrelationtoitsphasetransitions
AT bueramp thermalstabilityofdehydratedaamylaseintrehalosematricesinrelationtoitsphasetransitions
AT pilosofamr thermalstabilityofdehydratedaamylaseintrehalosematricesinrelationtoitsphasetransitions
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