Rheological modelling of enzymatic extrusion of rice starch
Autor(a) principal: | |
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Data de Publicação: | 1997 |
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/10400.14/6631 |
Resumo: | A rice starch mixture pre-mixed with thermostable α-amylase was extruded in a pilot co-rotating twin-screw extruder, with the die replaced by a slit rheometer. The apparent viscosity at the slit wall was determined for a variety of operating conditions. The factors studied were barrel temperature (70–110 °C), water content (550–650 g/kg rice mixture), flow rate (8 × 10−7 to 2.5 × 10−6 m3/s) and enzyme concentration (0·01–0·1 g/kg). The same screw configuration and rotational speed (225 rpm) were used. A rheological model incorporating the integrated effect of extrusion and enzymatic activity was developed with a stepwise regression of the experimental data, analysing after each step the variability of the model parameters with the different factors. It was found that for the range of experimental conditions in question the influence of each factor could be considered separately with good results, leading to a power-law type model with a constant behaviour index. The parameters obtained describing the influence of water content, temperature and shear rate were within the range of available literature data for non-enzymatic extrusion and the influence of the enzyme concentration was well described by a power-law dependency. |
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Rheological modelling of enzymatic extrusion of rice starchA rice starch mixture pre-mixed with thermostable α-amylase was extruded in a pilot co-rotating twin-screw extruder, with the die replaced by a slit rheometer. The apparent viscosity at the slit wall was determined for a variety of operating conditions. The factors studied were barrel temperature (70–110 °C), water content (550–650 g/kg rice mixture), flow rate (8 × 10−7 to 2.5 × 10−6 m3/s) and enzyme concentration (0·01–0·1 g/kg). The same screw configuration and rotational speed (225 rpm) were used. A rheological model incorporating the integrated effect of extrusion and enzymatic activity was developed with a stepwise regression of the experimental data, analysing after each step the variability of the model parameters with the different factors. It was found that for the range of experimental conditions in question the influence of each factor could be considered separately with good results, leading to a power-law type model with a constant behaviour index. The parameters obtained describing the influence of water content, temperature and shear rate were within the range of available literature data for non-enzymatic extrusion and the influence of the enzyme concentration was well described by a power-law dependency.ElsevierVeritati - Repositório Institucional da Universidade Católica PortuguesaTomás, Rui L.Oliveira, Jorge C.McCarth, Kathryn L.2011-10-21T10:42:21Z19971997-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.14/6631engTOMÁS, Rui L. ; OLIVEIRA, Jorge C. ; McCARTH, Kathryn L. - Rheological modelling of enzymatic extrusion of rice starch. Journal of Food Engineering. ISSN 0260-8774. Vol. 32, n.º 2 (1997), p. 167-177info: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:RCAAP2023-07-12T17:10:53Zoai:repositorio.ucp.pt:10400.14/6631Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T18:06:03.246610Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Rheological modelling of enzymatic extrusion of rice starch |
title |
Rheological modelling of enzymatic extrusion of rice starch |
spellingShingle |
Rheological modelling of enzymatic extrusion of rice starch Tomás, Rui L. |
title_short |
Rheological modelling of enzymatic extrusion of rice starch |
title_full |
Rheological modelling of enzymatic extrusion of rice starch |
title_fullStr |
Rheological modelling of enzymatic extrusion of rice starch |
title_full_unstemmed |
Rheological modelling of enzymatic extrusion of rice starch |
title_sort |
Rheological modelling of enzymatic extrusion of rice starch |
author |
Tomás, Rui L. |
author_facet |
Tomás, Rui L. Oliveira, Jorge C. McCarth, Kathryn L. |
author_role |
author |
author2 |
Oliveira, Jorge C. McCarth, Kathryn L. |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Veritati - Repositório Institucional da Universidade Católica Portuguesa |
dc.contributor.author.fl_str_mv |
Tomás, Rui L. Oliveira, Jorge C. McCarth, Kathryn L. |
description |
A rice starch mixture pre-mixed with thermostable α-amylase was extruded in a pilot co-rotating twin-screw extruder, with the die replaced by a slit rheometer. The apparent viscosity at the slit wall was determined for a variety of operating conditions. The factors studied were barrel temperature (70–110 °C), water content (550–650 g/kg rice mixture), flow rate (8 × 10−7 to 2.5 × 10−6 m3/s) and enzyme concentration (0·01–0·1 g/kg). The same screw configuration and rotational speed (225 rpm) were used. A rheological model incorporating the integrated effect of extrusion and enzymatic activity was developed with a stepwise regression of the experimental data, analysing after each step the variability of the model parameters with the different factors. It was found that for the range of experimental conditions in question the influence of each factor could be considered separately with good results, leading to a power-law type model with a constant behaviour index. The parameters obtained describing the influence of water content, temperature and shear rate were within the range of available literature data for non-enzymatic extrusion and the influence of the enzyme concentration was well described by a power-law dependency. |
publishDate |
1997 |
dc.date.none.fl_str_mv |
1997 1997-01-01T00:00:00Z 2011-10-21T10:42:21Z |
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/10400.14/6631 |
url |
http://hdl.handle.net/10400.14/6631 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
TOMÁS, Rui L. ; OLIVEIRA, Jorge C. ; McCARTH, Kathryn L. - Rheological modelling of enzymatic extrusion of rice starch. Journal of Food Engineering. ISSN 0260-8774. Vol. 32, n.º 2 (1997), p. 167-177 |
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 |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
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 |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799131726415396864 |