Drying kinetics and mass transfer properties in the drying of thistle flower
Autor(a) principal: | |
---|---|
Data de Publicação: | 2019 |
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=S1981-67232019000100457 |
Resumo: | Abstract Thistle flowers, and particularly their stigmas, are used to coagulate milk in the production of a number of traditional Portuguese cheeses due to their high milk-clotting activity provided by the high content of aspartic proteases. The aim of the present work was to determine the mass transfer properties of thistle flower under different drying conditions: natural drying and convective drying. Convective drying took place in a convection chamber set at different temperatures (35 to 65 °C) and the process was terminated when the sample presented a moisture content of about 5% or less. The traditional drying method was also used, placing the thistle flowers in a dry place sheltered from the sun, and leaving them to dehydrate at the variable room temperature. The present work allowed for the conclusion that convective drying was much faster than natural drying, and that the drying rate increased with temperature. The drying curve revealed an initial constant rate period followed by a falling rate. All the five thin layer models tested to fit the experimental data were shown to adequately describe the drying of the thistle flowers, but the best one was the Page model. The drying constant increased with temperature as did the effective diffusivity and the mass transfer coefficient. The results allowed one to estimate the activation energy for moisture diffusion (57 kJ/mol) and for convective mass transfer (78 kJ/mol). Thus this study showed the possibilities for designing efficient drying processes for the thistle flower used for milk-clotting in the manufacture of traditional cheeses. |
id |
ITAL-1_915b3225f818e417746b0e7fccc87d40 |
---|---|
oai_identifier_str |
oai:scielo:S1981-67232019000100457 |
network_acronym_str |
ITAL-1 |
network_name_str |
Brazilian Journal of Food Technology |
repository_id_str |
|
spelling |
Drying kinetics and mass transfer properties in the drying of thistle flowerActivation energyConvective dryingDiffusion coefficientMass transfer coefficientMilk clottingThin layer modelAbstract Thistle flowers, and particularly their stigmas, are used to coagulate milk in the production of a number of traditional Portuguese cheeses due to their high milk-clotting activity provided by the high content of aspartic proteases. The aim of the present work was to determine the mass transfer properties of thistle flower under different drying conditions: natural drying and convective drying. Convective drying took place in a convection chamber set at different temperatures (35 to 65 °C) and the process was terminated when the sample presented a moisture content of about 5% or less. The traditional drying method was also used, placing the thistle flowers in a dry place sheltered from the sun, and leaving them to dehydrate at the variable room temperature. The present work allowed for the conclusion that convective drying was much faster than natural drying, and that the drying rate increased with temperature. The drying curve revealed an initial constant rate period followed by a falling rate. All the five thin layer models tested to fit the experimental data were shown to adequately describe the drying of the thistle flowers, but the best one was the Page model. The drying constant increased with temperature as did the effective diffusivity and the mass transfer coefficient. The results allowed one to estimate the activation energy for moisture diffusion (57 kJ/mol) and for convective mass transfer (78 kJ/mol). Thus this study showed the possibilities for designing efficient drying processes for the thistle flower used for milk-clotting in the manufacture of traditional cheeses.Instituto de Tecnologia de Alimentos - ITAL2019-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S1981-67232019000100457Brazilian Journal of Food Technology v.22 2019reponame:Brazilian Journal of Food Technologyinstname:Instituto de Tecnologia de Alimentos (ITAL)instacron:ITAL10.1590/1981-6723.05119info:eu-repo/semantics/openAccessGuiné,Raquel P. F.Fontes,LuísaLima,Maria João Reiseng2019-10-22T00:00:00Zoai:scielo:S1981-67232019000100457Revistahttp://bjft.ital.sp.gov.br/https://old.scielo.br/oai/scielo-oai.phpbjftsec@ital.sp.gov.br||bjftsec@ital.sp.gov.br1981-67231516-7275opendoar:2019-10-22T00:00Brazilian Journal of Food Technology - Instituto de Tecnologia de Alimentos (ITAL)false |
dc.title.none.fl_str_mv |
Drying kinetics and mass transfer properties in the drying of thistle flower |
title |
Drying kinetics and mass transfer properties in the drying of thistle flower |
spellingShingle |
Drying kinetics and mass transfer properties in the drying of thistle flower Guiné,Raquel P. F. Activation energy Convective drying Diffusion coefficient Mass transfer coefficient Milk clotting Thin layer model |
title_short |
Drying kinetics and mass transfer properties in the drying of thistle flower |
title_full |
Drying kinetics and mass transfer properties in the drying of thistle flower |
title_fullStr |
Drying kinetics and mass transfer properties in the drying of thistle flower |
title_full_unstemmed |
Drying kinetics and mass transfer properties in the drying of thistle flower |
title_sort |
Drying kinetics and mass transfer properties in the drying of thistle flower |
author |
Guiné,Raquel P. F. |
author_facet |
Guiné,Raquel P. F. Fontes,Luísa Lima,Maria João Reis |
author_role |
author |
author2 |
Fontes,Luísa Lima,Maria João Reis |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Guiné,Raquel P. F. Fontes,Luísa Lima,Maria João Reis |
dc.subject.por.fl_str_mv |
Activation energy Convective drying Diffusion coefficient Mass transfer coefficient Milk clotting Thin layer model |
topic |
Activation energy Convective drying Diffusion coefficient Mass transfer coefficient Milk clotting Thin layer model |
description |
Abstract Thistle flowers, and particularly their stigmas, are used to coagulate milk in the production of a number of traditional Portuguese cheeses due to their high milk-clotting activity provided by the high content of aspartic proteases. The aim of the present work was to determine the mass transfer properties of thistle flower under different drying conditions: natural drying and convective drying. Convective drying took place in a convection chamber set at different temperatures (35 to 65 °C) and the process was terminated when the sample presented a moisture content of about 5% or less. The traditional drying method was also used, placing the thistle flowers in a dry place sheltered from the sun, and leaving them to dehydrate at the variable room temperature. The present work allowed for the conclusion that convective drying was much faster than natural drying, and that the drying rate increased with temperature. The drying curve revealed an initial constant rate period followed by a falling rate. All the five thin layer models tested to fit the experimental data were shown to adequately describe the drying of the thistle flowers, but the best one was the Page model. The drying constant increased with temperature as did the effective diffusivity and the mass transfer coefficient. The results allowed one to estimate the activation energy for moisture diffusion (57 kJ/mol) and for convective mass transfer (78 kJ/mol). Thus this study showed the possibilities for designing efficient drying processes for the thistle flower used for milk-clotting in the manufacture of traditional cheeses. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-01-01 |
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=S1981-67232019000100457 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1981-67232019000100457 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/1981-6723.05119 |
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.22 2019 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_ |
1752128702129373184 |