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Utilize este identificador para citar ou criar um link para este item: http://acervodigital.unesp.br/handle/11449/6943
Título: 
Thermal and Rheological Properties of a Family of Botryosphaerans Produced by Botryosphaeria rhodina MAMB-05
Autor(es): 
Instituição: 
  • Universidade Estadual Paulista (UNESP)
  • Lakehead Univ
  • Universidade Estadual de Londrina (UEL)
  • Universidade Federal do Paraná (UFPR)
ISSN: 
1420-3049
Financiador: 
  • Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
  • Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
  • PROPPG-UEL
Resumo: 
Differential scanning calorimetry (DSC), thermogravimetry (TG) and Fourier-transform infra-red spectroscopy (FT-IR) analyses were performed to investigate changes in the physico-chemical properties of botryosphaerans, a family of exopolysaccharides (EPS) produced by the fungus Botryosphaeria rhodina MAMB-05 grown on glucose (EPS(GLC)), sucrose (EPS(SUC)) and fructose (EPS(FRU)). A slight endothermic transition and small mass loss attributable to the removal of water of hydration were observed in the DSC and TG analyses, respectively, for the three EPS samples. The FT-IR spectra confirmed no structural changes occurred during thermal treatment. Viscometry was utilized to obtain information on the rheological behaviour of the EPS in aqueous solutions. The Power Law and Cross Equations determined the natural pseudoplastic characteristics of the EPS. Comparatively, results obtained for EPS produced when B. rhodina MAMB-05 was grown on each of the three carbohydrate sources demonstrated similar apparent viscosity values for EPS(GLC) and EPS(SUC), while EPS(FRU) displayed the lowest apparent viscosity of the three botryosphaerans, suggesting a higher degree of ramification and lower Mw. EPS(GLC) and EPSSUC possessed similar degrees of ramification. The slight differences found in their viscosities can be explained by the differences in the type of branching among the three botryosphaerans, thus varying the strength of intermolecular interactions and consequently, consistency and viscosity. The physico-chemical studies of botryosphaerans represent the originality of this work, and the knowledge of these properties is an important criterion for potential applications.
Data de publicação: 
1-Set-2011
Citação: 
Molecules. Basel: Mdpi Ag, v. 16, n. 9, p. 7488-7501, 2011.
Duração: 
7488-7501
Publicador: 
Mdpi Ag
Palavras-chaves: 
  • beta-glucans
  • botryosphaeran
  • thermal analysis
  • FT-IR spectroscopy
  • rheology
Fonte: 
http://dx.doi.org/10.3390/molecules16097488
Endereço permanente: 
http://hdl.handle.net/11449/6943
Direitos de acesso: 
Acesso aberto
Tipo: 
outro
Fonte completa:
http://repositorio.unesp.br/handle/11449/6943
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