Structural collapse prevents β-carotene loss in a supercooled polymeric matrix
The kinetics of degradation and surface color changes of β-carotene encapsulated in a polymeric matrix (PVP-40) and its relationship with physical changes (manifested as structural collapse) of the matrix were studied during storage of samples at several water activities at constant temperature. The...
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2006
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218561_v54_n1_p79_Prado http://hdl.handle.net/20.500.12110/paper_00218561_v54_n1_p79_Prado |
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paper:paper_00218561_v54_n1_p79_Prado2023-06-08T14:42:13Z Structural collapse prevents β-carotene loss in a supercooled polymeric matrix Buera, María del Pilar Elizalde, Beatriz Emilia β-carotene Collapse Encapsulation Glass transition Molecular mobility beta carotene polymer article chemistry cold color humidity kinetics physical chemistry beta Carotene Chemistry, Physical Cold Color Humidity Kinetics Polymers The kinetics of degradation and surface color changes of β-carotene encapsulated in a polymeric matrix (PVP-40) and its relationship with physical changes (manifested as structural collapse) of the matrix were studied during storage of samples at several water activities at constant temperature. The degradation rate constants obtained decreased with an increase in the relative humidity (RH) of the storage atmosphere. β-Carotene losses were observed mainly at RHs below the glass transition temperature (Tg) of the corresponding systems, and the lower degradation constant rates were observed under conditions where the matrices were fully plasticized (i.e., rubbery) and collapsed (RH, 64 and 75%). An inverse correlation was observed between collapse and degradation rate constants. The results presented here indicated that the molecular mobility of the matrix is not rate limiting for the degradation of β-carotene. Factors such as microstructure and porosity of the polymeric matrix may be more important as modifiers of kinetic reactions. Surface color was not a sensitive indicator of β-carotene retention, because it was mostly affected by the degree of matrix hydration and collapse phenomena. © 2006 American Chemical Society. Fil:Buera, M.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Elizalde, B.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2006 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218561_v54_n1_p79_Prado http://hdl.handle.net/20.500.12110/paper_00218561_v54_n1_p79_Prado |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
β-carotene Collapse Encapsulation Glass transition Molecular mobility beta carotene polymer article chemistry cold color humidity kinetics physical chemistry beta Carotene Chemistry, Physical Cold Color Humidity Kinetics Polymers |
| spellingShingle |
β-carotene Collapse Encapsulation Glass transition Molecular mobility beta carotene polymer article chemistry cold color humidity kinetics physical chemistry beta Carotene Chemistry, Physical Cold Color Humidity Kinetics Polymers Buera, María del Pilar Elizalde, Beatriz Emilia Structural collapse prevents β-carotene loss in a supercooled polymeric matrix |
| topic_facet |
β-carotene Collapse Encapsulation Glass transition Molecular mobility beta carotene polymer article chemistry cold color humidity kinetics physical chemistry beta Carotene Chemistry, Physical Cold Color Humidity Kinetics Polymers |
| description |
The kinetics of degradation and surface color changes of β-carotene encapsulated in a polymeric matrix (PVP-40) and its relationship with physical changes (manifested as structural collapse) of the matrix were studied during storage of samples at several water activities at constant temperature. The degradation rate constants obtained decreased with an increase in the relative humidity (RH) of the storage atmosphere. β-Carotene losses were observed mainly at RHs below the glass transition temperature (Tg) of the corresponding systems, and the lower degradation constant rates were observed under conditions where the matrices were fully plasticized (i.e., rubbery) and collapsed (RH, 64 and 75%). An inverse correlation was observed between collapse and degradation rate constants. The results presented here indicated that the molecular mobility of the matrix is not rate limiting for the degradation of β-carotene. Factors such as microstructure and porosity of the polymeric matrix may be more important as modifiers of kinetic reactions. Surface color was not a sensitive indicator of β-carotene retention, because it was mostly affected by the degree of matrix hydration and collapse phenomena. © 2006 American Chemical Society. |
| author |
Buera, María del Pilar Elizalde, Beatriz Emilia |
| author_facet |
Buera, María del Pilar Elizalde, Beatriz Emilia |
| author_sort |
Buera, María del Pilar |
| title |
Structural collapse prevents β-carotene loss in a supercooled polymeric matrix |
| title_short |
Structural collapse prevents β-carotene loss in a supercooled polymeric matrix |
| title_full |
Structural collapse prevents β-carotene loss in a supercooled polymeric matrix |
| title_fullStr |
Structural collapse prevents β-carotene loss in a supercooled polymeric matrix |
| title_full_unstemmed |
Structural collapse prevents β-carotene loss in a supercooled polymeric matrix |
| title_sort |
structural collapse prevents β-carotene loss in a supercooled polymeric matrix |
| publishDate |
2006 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218561_v54_n1_p79_Prado http://hdl.handle.net/20.500.12110/paper_00218561_v54_n1_p79_Prado |
| work_keys_str_mv |
AT bueramariadelpilar structuralcollapsepreventsbcarotenelossinasupercooledpolymericmatrix AT elizaldebeatrizemilia structuralcollapsepreventsbcarotenelossinasupercooledpolymericmatrix |
| _version_ |
1768544536645074944 |