Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature

Detalhes bibliográficos
Autor(a) principal: Bertuzzi,Maria Alejandra
Data de Publicação: 2012
Outros Autores: Gottifredi,Juan Carlos, Armada,Margarita
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Brazilian Journal of Food Technology
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1981-67232012000300005
Resumo: In the present study, a better knowledge of the influence of plasticizer content, storage relative humidity and film thickness on the mechanical properties of high amylose corn starch based films gelatinized at low temperature, is presented. The mechanical properties, tensile strength and percentage of elongation at break of high amylose corn starch films plasticized with glycerol were evaluated using tension tests. The films exhibited an increase in elongation and a decrease in tensile strength with increasing plasticizer concentration. When the glycerol level was high, some fissures were detected in the dry films, possible due to phase separation (starch-glycerol) phenomena. Film crystallinity is related to the reorganization capacity of the polymer chain, and thus the relative film crystallinity should increase with plasticizer content (glycerol and water). The mechanical properties were found to be strongly dependent on the water content due to the hydrophilic nature of starch films. The influence of moisture sorption on tensile strength was similar to that of plasticization with glycerol. The relationship between polymer chain mobility and water content explained this behavior. Elongation suffered a different effect and maximum values were reached at 45% relative humidity. The final drop in elongation was due to a softening of the structure at high relative humidity. The thicker the film the longer the drying time required, leading to greater relative crystallinity due to the corresponding increase in the possibility for chain reorganization. As a consequence, linear increases in tensile strength and elongation were observed with film thickness over the whole range studied (30 to 100 µm).
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spelling Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperatureStarch filmsMechanical propertiesTensile strengthElongation at breakCrystallinityIn the present study, a better knowledge of the influence of plasticizer content, storage relative humidity and film thickness on the mechanical properties of high amylose corn starch based films gelatinized at low temperature, is presented. The mechanical properties, tensile strength and percentage of elongation at break of high amylose corn starch films plasticized with glycerol were evaluated using tension tests. The films exhibited an increase in elongation and a decrease in tensile strength with increasing plasticizer concentration. When the glycerol level was high, some fissures were detected in the dry films, possible due to phase separation (starch-glycerol) phenomena. Film crystallinity is related to the reorganization capacity of the polymer chain, and thus the relative film crystallinity should increase with plasticizer content (glycerol and water). The mechanical properties were found to be strongly dependent on the water content due to the hydrophilic nature of starch films. The influence of moisture sorption on tensile strength was similar to that of plasticization with glycerol. The relationship between polymer chain mobility and water content explained this behavior. Elongation suffered a different effect and maximum values were reached at 45% relative humidity. The final drop in elongation was due to a softening of the structure at high relative humidity. The thicker the film the longer the drying time required, leading to greater relative crystallinity due to the corresponding increase in the possibility for chain reorganization. As a consequence, linear increases in tensile strength and elongation were observed with film thickness over the whole range studied (30 to 100 µm).Instituto de Tecnologia de Alimentos - ITAL2012-09-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S1981-67232012000300005Brazilian Journal of Food Technology v.15 n.3 2012reponame:Brazilian Journal of Food Technologyinstname:Instituto de Tecnologia de Alimentos (ITAL)instacron:ITAL10.1590/S1981-67232012005000015info:eu-repo/semantics/openAccessBertuzzi,Maria AlejandraGottifredi,Juan CarlosArmada,Margaritaeng2012-09-13T00:00:00Zoai:scielo:S1981-67232012000300005Revistahttp://bjft.ital.sp.gov.br/https://old.scielo.br/oai/scielo-oai.phpbjftsec@ital.sp.gov.br||bjftsec@ital.sp.gov.br1981-67231516-7275opendoar:2012-09-13T00:00Brazilian Journal of Food Technology - Instituto de Tecnologia de Alimentos (ITAL)false
dc.title.none.fl_str_mv Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
title Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
spellingShingle Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
Bertuzzi,Maria Alejandra
Starch films
Mechanical properties
Tensile strength
Elongation at break
Crystallinity
title_short Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
title_full Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
title_fullStr Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
title_full_unstemmed Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
title_sort Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
author Bertuzzi,Maria Alejandra
author_facet Bertuzzi,Maria Alejandra
Gottifredi,Juan Carlos
Armada,Margarita
author_role author
author2 Gottifredi,Juan Carlos
Armada,Margarita
author2_role author
author
dc.contributor.author.fl_str_mv Bertuzzi,Maria Alejandra
Gottifredi,Juan Carlos
Armada,Margarita
dc.subject.por.fl_str_mv Starch films
Mechanical properties
Tensile strength
Elongation at break
Crystallinity
topic Starch films
Mechanical properties
Tensile strength
Elongation at break
Crystallinity
description In the present study, a better knowledge of the influence of plasticizer content, storage relative humidity and film thickness on the mechanical properties of high amylose corn starch based films gelatinized at low temperature, is presented. The mechanical properties, tensile strength and percentage of elongation at break of high amylose corn starch films plasticized with glycerol were evaluated using tension tests. The films exhibited an increase in elongation and a decrease in tensile strength with increasing plasticizer concentration. When the glycerol level was high, some fissures were detected in the dry films, possible due to phase separation (starch-glycerol) phenomena. Film crystallinity is related to the reorganization capacity of the polymer chain, and thus the relative film crystallinity should increase with plasticizer content (glycerol and water). The mechanical properties were found to be strongly dependent on the water content due to the hydrophilic nature of starch films. The influence of moisture sorption on tensile strength was similar to that of plasticization with glycerol. The relationship between polymer chain mobility and water content explained this behavior. Elongation suffered a different effect and maximum values were reached at 45% relative humidity. The final drop in elongation was due to a softening of the structure at high relative humidity. The thicker the film the longer the drying time required, leading to greater relative crystallinity due to the corresponding increase in the possibility for chain reorganization. As a consequence, linear increases in tensile strength and elongation were observed with film thickness over the whole range studied (30 to 100 µm).
publishDate 2012
dc.date.none.fl_str_mv 2012-09-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1981-67232012000300005
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1981-67232012000300005
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S1981-67232012005000015
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Instituto de Tecnologia de Alimentos - ITAL
publisher.none.fl_str_mv Instituto de Tecnologia de Alimentos - ITAL
dc.source.none.fl_str_mv Brazilian Journal of Food Technology v.15 n.3 2012
reponame:Brazilian Journal of Food Technology
instname:Instituto de Tecnologia de Alimentos (ITAL)
instacron:ITAL
instname_str Instituto de Tecnologia de Alimentos (ITAL)
instacron_str ITAL
institution ITAL
reponame_str Brazilian Journal of Food Technology
collection Brazilian Journal of Food Technology
repository.name.fl_str_mv Brazilian Journal of Food Technology - Instituto de Tecnologia de Alimentos (ITAL)
repository.mail.fl_str_mv bjftsec@ital.sp.gov.br||bjftsec@ital.sp.gov.br
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