Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA)
Autor(a) principal: | |
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Data de Publicação: | 2000 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.14/6450 |
Resumo: | This work describes a method to study glass transition on native starch powders, based on dynamical mechanical thermal analysis using compression tests, and was applied to wheat flour (13.5% water content). This method will allow the determination of Tg in native (unprocessed) starchy materials, with minimal disturbance of the natural structures. The influence of the test conditions (heating rate, frequency and strain) on the glass transition measurements was determined using factorial designs. The values of Tg determined as the maxima of the energy dissipation (peaks in E ) of native flour and of freezedried pre-gelatinized flour were not statistically different (around 64 C). The heating rate did not affect the measurements in the range tested (0.25 to 1 C min 1). An interactive effect of the strain amplitude and the frequency was detected. The significance of this interaction can be caused by differences in mechanical energy dissipation, which would indicate that not only temperature but also the total energy input may affect this transition. Slight effects of phase separation between gluten and starch were found on native flour. |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA)Phase transitionsStarchViscoelastic propertiesThis work describes a method to study glass transition on native starch powders, based on dynamical mechanical thermal analysis using compression tests, and was applied to wheat flour (13.5% water content). This method will allow the determination of Tg in native (unprocessed) starchy materials, with minimal disturbance of the natural structures. The influence of the test conditions (heating rate, frequency and strain) on the glass transition measurements was determined using factorial designs. The values of Tg determined as the maxima of the energy dissipation (peaks in E ) of native flour and of freezedried pre-gelatinized flour were not statistically different (around 64 C). The heating rate did not affect the measurements in the range tested (0.25 to 1 C min 1). An interactive effect of the strain amplitude and the frequency was detected. The significance of this interaction can be caused by differences in mechanical energy dissipation, which would indicate that not only temperature but also the total energy input may affect this transition. Slight effects of phase separation between gluten and starch were found on native flour.Wiley Blackwell Science LtdVeritati - Repositório Institucional da Universidade Católica PortuguesaPereira, Pedro M.Oliveira, Jorge C.2011-10-18T18:16:31Z20002000-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.14/6450engPEREIRA, Pedro M.; OLIVEIRA, Jorge C. - Wheat flour by dynamic mechanical thermal analysis (DMTA). International Journal of Food Science and Technology. ISSN 0950-5423. Vol. 35 (2000), p. 183–192info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-12T17:10:44ZPortal AgregadorONG |
dc.title.none.fl_str_mv |
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA) |
title |
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA) |
spellingShingle |
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA) Pereira, Pedro M. Phase transitions Starch Viscoelastic properties |
title_short |
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA) |
title_full |
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA) |
title_fullStr |
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA) |
title_full_unstemmed |
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA) |
title_sort |
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA) |
author |
Pereira, Pedro M. |
author_facet |
Pereira, Pedro M. Oliveira, Jorge C. |
author_role |
author |
author2 |
Oliveira, Jorge C. |
author2_role |
author |
dc.contributor.none.fl_str_mv |
Veritati - Repositório Institucional da Universidade Católica Portuguesa |
dc.contributor.author.fl_str_mv |
Pereira, Pedro M. Oliveira, Jorge C. |
dc.subject.por.fl_str_mv |
Phase transitions Starch Viscoelastic properties |
topic |
Phase transitions Starch Viscoelastic properties |
description |
This work describes a method to study glass transition on native starch powders, based on dynamical mechanical thermal analysis using compression tests, and was applied to wheat flour (13.5% water content). This method will allow the determination of Tg in native (unprocessed) starchy materials, with minimal disturbance of the natural structures. The influence of the test conditions (heating rate, frequency and strain) on the glass transition measurements was determined using factorial designs. The values of Tg determined as the maxima of the energy dissipation (peaks in E ) of native flour and of freezedried pre-gelatinized flour were not statistically different (around 64 C). The heating rate did not affect the measurements in the range tested (0.25 to 1 C min 1). An interactive effect of the strain amplitude and the frequency was detected. The significance of this interaction can be caused by differences in mechanical energy dissipation, which would indicate that not only temperature but also the total energy input may affect this transition. Slight effects of phase separation between gluten and starch were found on native flour. |
publishDate |
2000 |
dc.date.none.fl_str_mv |
2000 2000-01-01T00:00:00Z 2011-10-18T18:16:31Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.14/6450 |
url |
http://hdl.handle.net/10400.14/6450 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
PEREIRA, Pedro M.; OLIVEIRA, Jorge C. - Wheat flour by dynamic mechanical thermal analysis (DMTA). International Journal of Food Science and Technology. ISSN 0950-5423. Vol. 35 (2000), p. 183–192 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Wiley Blackwell Science Ltd |
publisher.none.fl_str_mv |
Wiley Blackwell Science Ltd |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
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repository.mail.fl_str_mv |
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_version_ |
1777303118921334784 |