Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices

The thermal stability of enzymes lactase and invertase in dried, amorphous matrices of sugars (trehalose, malrose, lactose, sucrose, raffinose) and some other selected systems (casein, PVP, milk) was studied. The glass transition temperature (T(g)) was limited as a threshold parameter for predicting...

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Autores principales:	Schebor, Carolina C., Burín, Leila, Buera, María del Pilar
Publicado:	1997
Materias:	Amorphous materials Casein Catalyst activity Crystallization Enzyme immobilization Glass transition Maltose Sugar (sucrose) Thermal effects Thermodynamic stability Invertase Lactase Lactose Raffinose Trehalose Enzymes beta fructofuranosidase beta galactosidase casein disaccharide glycosidase lactase povidone sucrose trehalose animal article chemistry crystallization desiccation enzyme stability heat kinetics metabolism milk physical chemistry Animals beta-Fructofuranosidase beta-Galactosidase Caseins Chemistry, Physical Desiccation Disaccharides Enzyme Stability Glycoside Hydrolases Heat Kinetics Milk Povidone Sucrose Animalia
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_87567938_v13_n6_p857_Schebor http://hdl.handle.net/20.500.12110/paper_87567938_v13_n6_p857_Schebor
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

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spelling	paper:paper_87567938_v13_n6_p857_Schebor2023-06-08T16:36:53Z Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices Schebor, Carolina C. Burín, Leila Buera, María del Pilar Amorphous materials Casein Catalyst activity Crystallization Enzyme immobilization Glass transition Maltose Sugar (sucrose) Thermal effects Thermodynamic stability Invertase Lactase Lactose Raffinose Trehalose Enzymes beta fructofuranosidase beta galactosidase casein disaccharide glycosidase lactase povidone sucrose trehalose animal article chemistry crystallization desiccation enzyme stability heat kinetics metabolism milk physical chemistry Animals beta-Fructofuranosidase beta-Galactosidase Caseins Chemistry, Physical Crystallization Desiccation Disaccharides Enzyme Stability Glycoside Hydrolases Heat Kinetics Lactase Milk Povidone Sucrose Trehalose Animalia The thermal stability of enzymes lactase and invertase in dried, amorphous matrices of sugars (trehalose, malrose, lactose, sucrose, raffinose) and some other selected systems (casein, PVP, milk) was studied. The glass transition temperature (T(g)) was limited as a threshold parameter for predicting enzyme inactivation because (a) enzyme inactivation was observed in glassy matrices, (b) a specific effect of enzyme stabilization by certain matrices particularly trehalose was observed, and (c) enzyme stability appeared to depend on heating temperature (T) 'per se' rather than (T - T(g)). For these reasons, a protective mechanism by sugars related to the maintenance of the tertiary structure of the enzyme was favored. A rapid loss of enzyme (lactase) activity was observed in heated sucrose systems at T > T(g), and this was attributed to sucrose crystallization since it is known that upon crystallization the protective effect of sugars is lost. Thus, the stabilizing effect could be indirectly affected by the T(g) of the matrix, since crystallization of sugars only occurs above T(g). Trehalose model systems (with added invertase) showed an exceptional stability toward 'darkening' (e.g., nonenzymatic browning) when heated in the dried state to elevated temperatures and for long periods of time. The thermal stability of enzymes lactase and invertase in dried, amorphous matrices of sugars (trehalose, maltose, lactose, sucrose, raffinose) and some other selected systems (casein, PVP, milk) was studied. The glass transition temperature (Tg) was limited as a threshold parameter for predicting enzyme inactivation because (a) enzyme inactivation was observed in glassy matrices, (b) a specific effect of enzyme stabilization by certain matrices particularly trehalose was observed, and (c) enzyme stability appeared to depend on heating temperature (T) `per se' rather than (T-Tg). For these reasons, a protective mechanism by sugars related to the maintenance of the tertiary structure of the enzyme was favored. A rapid loss of enzyme (lactase) activity was observed in heated sucrose systems at T>Tg, and this was attributed to sucrose crystallization since it is known that upon crystallization the protective effect of sugars is lost. Thus, the stabilizing effect could be indirectly affected by the Tg of the matrix, since crystallization of sugars only occurs above Tg. Trehalose model systems (with added invertase) showed an exceptional stability toward `darkening' (e.g., non-enzymatic browning) when heated in the dried state to elevated temperatures and for long periods of time. Fil:Schebor, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Burin, L. 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. 1997 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_87567938_v13_n6_p857_Schebor http://hdl.handle.net/20.500.12110/paper_87567938_v13_n6_p857_Schebor
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Amorphous materials Casein Catalyst activity Crystallization Enzyme immobilization Glass transition Maltose Sugar (sucrose) Thermal effects Thermodynamic stability Invertase Lactase Lactose Raffinose Trehalose Enzymes beta fructofuranosidase beta galactosidase casein disaccharide glycosidase lactase povidone sucrose trehalose animal article chemistry crystallization desiccation enzyme stability heat kinetics metabolism milk physical chemistry Animals beta-Fructofuranosidase beta-Galactosidase Caseins Chemistry, Physical Crystallization Desiccation Disaccharides Enzyme Stability Glycoside Hydrolases Heat Kinetics Lactase Milk Povidone Sucrose Trehalose Animalia
spellingShingle	Amorphous materials Casein Catalyst activity Crystallization Enzyme immobilization Glass transition Maltose Sugar (sucrose) Thermal effects Thermodynamic stability Invertase Lactase Lactose Raffinose Trehalose Enzymes beta fructofuranosidase beta galactosidase casein disaccharide glycosidase lactase povidone sucrose trehalose animal article chemistry crystallization desiccation enzyme stability heat kinetics metabolism milk physical chemistry Animals beta-Fructofuranosidase beta-Galactosidase Caseins Chemistry, Physical Crystallization Desiccation Disaccharides Enzyme Stability Glycoside Hydrolases Heat Kinetics Lactase Milk Povidone Sucrose Trehalose Animalia Schebor, Carolina C. Burín, Leila Buera, María del Pilar Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices
topic_facet	Amorphous materials Casein Catalyst activity Crystallization Enzyme immobilization Glass transition Maltose Sugar (sucrose) Thermal effects Thermodynamic stability Invertase Lactase Lactose Raffinose Trehalose Enzymes beta fructofuranosidase beta galactosidase casein disaccharide glycosidase lactase povidone sucrose trehalose animal article chemistry crystallization desiccation enzyme stability heat kinetics metabolism milk physical chemistry Animals beta-Fructofuranosidase beta-Galactosidase Caseins Chemistry, Physical Crystallization Desiccation Disaccharides Enzyme Stability Glycoside Hydrolases Heat Kinetics Lactase Milk Povidone Sucrose Trehalose Animalia
description	The thermal stability of enzymes lactase and invertase in dried, amorphous matrices of sugars (trehalose, malrose, lactose, sucrose, raffinose) and some other selected systems (casein, PVP, milk) was studied. The glass transition temperature (T(g)) was limited as a threshold parameter for predicting enzyme inactivation because (a) enzyme inactivation was observed in glassy matrices, (b) a specific effect of enzyme stabilization by certain matrices particularly trehalose was observed, and (c) enzyme stability appeared to depend on heating temperature (T) 'per se' rather than (T - T(g)). For these reasons, a protective mechanism by sugars related to the maintenance of the tertiary structure of the enzyme was favored. A rapid loss of enzyme (lactase) activity was observed in heated sucrose systems at T > T(g), and this was attributed to sucrose crystallization since it is known that upon crystallization the protective effect of sugars is lost. Thus, the stabilizing effect could be indirectly affected by the T(g) of the matrix, since crystallization of sugars only occurs above T(g). Trehalose model systems (with added invertase) showed an exceptional stability toward 'darkening' (e.g., nonenzymatic browning) when heated in the dried state to elevated temperatures and for long periods of time. The thermal stability of enzymes lactase and invertase in dried, amorphous matrices of sugars (trehalose, maltose, lactose, sucrose, raffinose) and some other selected systems (casein, PVP, milk) was studied. The glass transition temperature (Tg) was limited as a threshold parameter for predicting enzyme inactivation because (a) enzyme inactivation was observed in glassy matrices, (b) a specific effect of enzyme stabilization by certain matrices particularly trehalose was observed, and (c) enzyme stability appeared to depend on heating temperature (T) `per se' rather than (T-Tg). For these reasons, a protective mechanism by sugars related to the maintenance of the tertiary structure of the enzyme was favored. A rapid loss of enzyme (lactase) activity was observed in heated sucrose systems at T>Tg, and this was attributed to sucrose crystallization since it is known that upon crystallization the protective effect of sugars is lost. Thus, the stabilizing effect could be indirectly affected by the Tg of the matrix, since crystallization of sugars only occurs above Tg. Trehalose model systems (with added invertase) showed an exceptional stability toward `darkening' (e.g., non-enzymatic browning) when heated in the dried state to elevated temperatures and for long periods of time.
author	Schebor, Carolina C. Burín, Leila Buera, María del Pilar
author_facet	Schebor, Carolina C. Burín, Leila Buera, María del Pilar
author_sort	Schebor, Carolina C.
title	Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices
title_short	Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices
title_full	Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices
title_fullStr	Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices
title_full_unstemmed	Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices
title_sort	glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices
publishDate	1997
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_87567938_v13_n6_p857_Schebor http://hdl.handle.net/20.500.12110/paper_87567938_v13_n6_p857_Schebor
work_keys_str_mv	AT scheborcarolinac glassystateandthermalinactivationofinvertaseandlactaseindriedamorphousmatrices AT burinleila glassystateandthermalinactivationofinvertaseandlactaseindriedamorphousmatrices AT bueramariadelpilar glassystateandthermalinactivationofinvertaseandlactaseindriedamorphousmatrices
_version_	1768541868688146432

Glassy state and thermal inactivation of invertase and lactase in dried amorphous matrices

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