Glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices

The thermal stability of a commercial preparation of neutral lactase (β-galactosidase) in low-moisture amorphous polymeric matrices of maltodextrin (MD dextrose equivalent (D.E.) = 10.9) and polyvinylpyrrolidone (PVP; MW 40 000) stored at various temperatures (T) was studied. The main objective was...

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Detalles Bibliográficos
Autores principales: Mazzobre, María Florencia, Buera, María del Pilar
Publicado: 1997
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_87567938_v13_n2_p195_Mazzobre
http://hdl.handle.net/20.500.12110/paper_87567938_v13_n2_p195_Mazzobre
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_87567938_v13_n2_p195_Mazzobre
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spelling paper:paper_87567938_v13_n2_p195_Mazzobre2023-06-08T16:36:53Z Glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices Mazzobre, María Florencia Buera, María del Pilar The thermal stability of a commercial preparation of neutral lactase (β-galactosidase) in low-moisture amorphous polymeric matrices of maltodextrin (MD dextrose equivalent (D.E.) = 10.9) and polyvinylpyrrolidone (PVP; MW 40 000) stored at various temperatures (T) was studied. The main objective was to analyze the usefulness of the glass transition temperature (T(g)) as a parameter for predicting the thermal stability of lactase in low-moisture glass-forming matrices. Loss of enzyme activity was observed during storage in glassy conditions (either in PVP or MD matrices), suggesting that, although molecular mobility may be significantly decreased in the glassy state, the protein molecule is still mobile enough to lead to enzyme inactivation. The results indicated that the change from the glassy to the rubbery state of the PVP matrix, where the enzyme was embedded, was not reflected in drastic changes in the temperature dependence of the thermal inactivation rate, as expected if it could be only predicted on the basis of physical changes of the matrices. The plasticizing effect of water is not the only factor to take into account when considering enzymatic stability in heated low-moisture amorphous systems. Fil:Mazzobre, M.F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Buera, M.D.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1997 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_87567938_v13_n2_p195_Mazzobre http://hdl.handle.net/20.500.12110/paper_87567938_v13_n2_p195_Mazzobre
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description The thermal stability of a commercial preparation of neutral lactase (β-galactosidase) in low-moisture amorphous polymeric matrices of maltodextrin (MD dextrose equivalent (D.E.) = 10.9) and polyvinylpyrrolidone (PVP; MW 40 000) stored at various temperatures (T) was studied. The main objective was to analyze the usefulness of the glass transition temperature (T(g)) as a parameter for predicting the thermal stability of lactase in low-moisture glass-forming matrices. Loss of enzyme activity was observed during storage in glassy conditions (either in PVP or MD matrices), suggesting that, although molecular mobility may be significantly decreased in the glassy state, the protein molecule is still mobile enough to lead to enzyme inactivation. The results indicated that the change from the glassy to the rubbery state of the PVP matrix, where the enzyme was embedded, was not reflected in drastic changes in the temperature dependence of the thermal inactivation rate, as expected if it could be only predicted on the basis of physical changes of the matrices. The plasticizing effect of water is not the only factor to take into account when considering enzymatic stability in heated low-moisture amorphous systems.
author Mazzobre, María Florencia
Buera, María del Pilar
spellingShingle Mazzobre, María Florencia
Buera, María del Pilar
Glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices
author_facet Mazzobre, María Florencia
Buera, María del Pilar
author_sort Mazzobre, María Florencia
title Glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices
title_short Glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices
title_full Glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices
title_fullStr Glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices
title_full_unstemmed Glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices
title_sort glass transition and thermal stability of lactase in low-moisture amorphous polymeric matrices
publishDate 1997
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_87567938_v13_n2_p195_Mazzobre
http://hdl.handle.net/20.500.12110/paper_87567938_v13_n2_p195_Mazzobre
work_keys_str_mv AT mazzobremariaflorencia glasstransitionandthermalstabilityoflactaseinlowmoistureamorphouspolymericmatrices
AT bueramariadelpilar glasstransitionandthermalstabilityoflactaseinlowmoistureamorphouspolymericmatrices
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