Effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: Part 2. Sugar crystallization rate and electrical conductivity behavior

Two of the sugars involved in the protection of living organisms, trehalose and sucrose, were employed to analyze the effect of different salts (MgCl2 , CaCl2 , KCl, NaCl) on sugar crystallization kinetics. The conductivity behavior in supercooled aqueous sugar-salt systems was also studied to evalu...

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Autores principales: Longinotti, Maria Paula, Mazzobre, María Florencia, Buera, María del Pilar, Corti, Horacio Roberto
Publicado: 2002
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v4_n3_p533_Longinotti
http://hdl.handle.net/20.500.12110/paper_14639076_v4_n3_p533_Longinotti
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spelling paper:paper_14639076_v4_n3_p533_Longinotti2023-06-08T16:16:36Z Effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: Part 2. Sugar crystallization rate and electrical conductivity behavior Longinotti, Maria Paula Mazzobre, María Florencia Buera, María del Pilar Corti, Horacio Roberto Corti, Horacio Roberto calcium chloride magnesium chloride potassium chloride sodium chloride sucrose trehalose water article carbohydrate analysis chemical interaction crystallization differential scanning calorimetry electric conductivity glass transition temperature kinetics solvation viscosity Two of the sugars involved in the protection of living organisms, trehalose and sucrose, were employed to analyze the effect of different salts (MgCl2 , CaCl2 , KCl, NaCl) on sugar crystallization kinetics. The conductivity behavior in supercooled aqueous sugar-salt systems was also studied to evaluate the extent of water-salt interactions. Trehalose and sucrose crystallization, evaluated by differential scanning calorimetry (DSC), was delayed by the presence of salt without affecting the glass transition temperature, Tg, of the system. Sugar crystallization rates increased as the temperature increased above Tg. The crystallization kinetics was analyzed using the Johnson-Mehl-Avrami-Kolmogorov equation (JMAK), and it was found that the index n varied from 4 for pure sugars to less than 2 for sugar-MgCl2 mixtures, suggesting that the presence of salts constrained the number of configurations for crystal growth. The electrical conductivity of NaCl and MgCl2 was measured in liquid and supercooled trehalose and sucrose aqueous solutions over a wide range of viscosity to find evidence of preferential solvation in the sugar-water solutions. The results indicated that large positive deviations from the Walden rule occur in these systems, due to the higher tendency of the ions to move in water-rich regions. The observed delayed crystallization of sugar in aqueous solutions containing salt could be attributed to effects on the nucleation mechanism of ion-induced microheterogeneities in the supercooled solutions. Fil:Longinotti, M.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Mazzobre, M.F. 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:Corti, H.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Corti, H.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2002 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v4_n3_p533_Longinotti http://hdl.handle.net/20.500.12110/paper_14639076_v4_n3_p533_Longinotti
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic calcium chloride
magnesium chloride
potassium chloride
sodium chloride
sucrose
trehalose
water
article
carbohydrate analysis
chemical interaction
crystallization
differential scanning calorimetry
electric conductivity
glass transition temperature
kinetics
solvation
viscosity
spellingShingle calcium chloride
magnesium chloride
potassium chloride
sodium chloride
sucrose
trehalose
water
article
carbohydrate analysis
chemical interaction
crystallization
differential scanning calorimetry
electric conductivity
glass transition temperature
kinetics
solvation
viscosity
Longinotti, Maria Paula
Mazzobre, María Florencia
Buera, María del Pilar
Corti, Horacio Roberto
Corti, Horacio Roberto
Effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: Part 2. Sugar crystallization rate and electrical conductivity behavior
topic_facet calcium chloride
magnesium chloride
potassium chloride
sodium chloride
sucrose
trehalose
water
article
carbohydrate analysis
chemical interaction
crystallization
differential scanning calorimetry
electric conductivity
glass transition temperature
kinetics
solvation
viscosity
description Two of the sugars involved in the protection of living organisms, trehalose and sucrose, were employed to analyze the effect of different salts (MgCl2 , CaCl2 , KCl, NaCl) on sugar crystallization kinetics. The conductivity behavior in supercooled aqueous sugar-salt systems was also studied to evaluate the extent of water-salt interactions. Trehalose and sucrose crystallization, evaluated by differential scanning calorimetry (DSC), was delayed by the presence of salt without affecting the glass transition temperature, Tg, of the system. Sugar crystallization rates increased as the temperature increased above Tg. The crystallization kinetics was analyzed using the Johnson-Mehl-Avrami-Kolmogorov equation (JMAK), and it was found that the index n varied from 4 for pure sugars to less than 2 for sugar-MgCl2 mixtures, suggesting that the presence of salts constrained the number of configurations for crystal growth. The electrical conductivity of NaCl and MgCl2 was measured in liquid and supercooled trehalose and sucrose aqueous solutions over a wide range of viscosity to find evidence of preferential solvation in the sugar-water solutions. The results indicated that large positive deviations from the Walden rule occur in these systems, due to the higher tendency of the ions to move in water-rich regions. The observed delayed crystallization of sugar in aqueous solutions containing salt could be attributed to effects on the nucleation mechanism of ion-induced microheterogeneities in the supercooled solutions.
author Longinotti, Maria Paula
Mazzobre, María Florencia
Buera, María del Pilar
Corti, Horacio Roberto
Corti, Horacio Roberto
author_facet Longinotti, Maria Paula
Mazzobre, María Florencia
Buera, María del Pilar
Corti, Horacio Roberto
Corti, Horacio Roberto
author_sort Longinotti, Maria Paula
title Effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: Part 2. Sugar crystallization rate and electrical conductivity behavior
title_short Effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: Part 2. Sugar crystallization rate and electrical conductivity behavior
title_full Effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: Part 2. Sugar crystallization rate and electrical conductivity behavior
title_fullStr Effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: Part 2. Sugar crystallization rate and electrical conductivity behavior
title_full_unstemmed Effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: Part 2. Sugar crystallization rate and electrical conductivity behavior
title_sort effect of salts on the properties of aqueous sugar systems in relation to biomaterial stabilization: part 2. sugar crystallization rate and electrical conductivity behavior
publishDate 2002
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v4_n3_p533_Longinotti
http://hdl.handle.net/20.500.12110/paper_14639076_v4_n3_p533_Longinotti
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