Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature
Autor(a) principal: | |
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Data de Publicação: | 2012 |
Outros Autores: | , |
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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Brazilian Journal of Food Technology |
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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 |
_version_ |
1752128700044804096 |