Adsorption isotherms and isosteric heat in Coffea arabica beans
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Pesquisa Agropecuária Tropical (Online) |
Texto Completo: | https://revistas.ufg.br/pat/article/view/58128 |
Resumo: | The knowledge of the adsorption hygroscopic equilibrium in coffee is pertinent for the adequacy of its storage, thus ensuring the quality of the product to the end consumer. The present study aimed to determine the adsorption isotherms of Arabica coffee (Acauã Novo cultivar) beans at the temperatures of 30 ºC, 40 ºC, 50 ºC and 60 ºC, as well as the integral adsorption isosteric heat. The equilibrium moisture contents were obtained by the gravimetric static method, using water activities between 0.10 and 0.83 (decimal). From the obtained data, several mathematical models were fitted to represent the adsorption isotherms. The statistical criteria for selecting the best model were the coefficient of determination, estimated mean standard error, relative mean error and distribution of residues. The Peleg model was the one that best represented the adsorption isotherms of the Arabica coffee beans under the studied conditions. The isotherms showed a sigmoidal type II shape. For a constant water activity, an increase in the temperature promotes a decrease in the equilibrium moisture content of Arabica coffee beans. In a moisture content range between 0.0191 and 0.2534 (dry base), the isosteric heat values ranged from 4,042.19 kJ kg-1 to 2,395.48 kJ kg-1. KEYWORDS: Hygroscopic equilibrium, mathematical modeling, moisture content. |
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Adsorption isotherms and isosteric heat in Coffea arabica beansIsotermas de adsorção e calor isostérico em grãos de Coffea arabicaThe knowledge of the adsorption hygroscopic equilibrium in coffee is pertinent for the adequacy of its storage, thus ensuring the quality of the product to the end consumer. The present study aimed to determine the adsorption isotherms of Arabica coffee (Acauã Novo cultivar) beans at the temperatures of 30 ºC, 40 ºC, 50 ºC and 60 ºC, as well as the integral adsorption isosteric heat. The equilibrium moisture contents were obtained by the gravimetric static method, using water activities between 0.10 and 0.83 (decimal). From the obtained data, several mathematical models were fitted to represent the adsorption isotherms. The statistical criteria for selecting the best model were the coefficient of determination, estimated mean standard error, relative mean error and distribution of residues. The Peleg model was the one that best represented the adsorption isotherms of the Arabica coffee beans under the studied conditions. The isotherms showed a sigmoidal type II shape. For a constant water activity, an increase in the temperature promotes a decrease in the equilibrium moisture content of Arabica coffee beans. In a moisture content range between 0.0191 and 0.2534 (dry base), the isosteric heat values ranged from 4,042.19 kJ kg-1 to 2,395.48 kJ kg-1. KEYWORDS: Hygroscopic equilibrium, mathematical modeling, moisture content.O conhecimento do equilíbrio higroscópio de adsorção em café é pertinente para a adequação de seu armazenamento, garantindo a qualidade do produto até o consumidor final. Objetivou-se determinar as isotermas de adsorção de grãos de café Arábica (cultivar Acauã Novo) nas temperaturas de 30 ºC, 40 ºC, 50 ºC e 60 ºC, bem como o calor isostérico integral de adsorção. Os teores de água de equilíbrio foram obtidos pelo método estático gravimétrico, com atividades de água entre 0,10 e 0,83 (decimal). A partir dos dados obtidos, foram ajustados diversos modelos matemáticos para representar as isotermas de adsorção. Os critérios estatísticos para a seleção do melhor modelo foram o coeficiente de determinação, erro médio estimado, erro médio relativo e a distribuição de resíduos. O modelo de Peleg foi o que melhor representou as isotermas de adsorção dos grãos de café Arábica nas condições estudadas. As isotermas apresentaram formato sigmoidal tipo II. Sob atividade de água constante, o aumento da temperatura promove diminuição no equilíbrio do teor de umidade em grãos de café Arábica. Os valores de calor isostérico com teor de água entre 0,0191 e 0,2534 (base seca) variaram de 4.042,19 kJ kg-1 a 2.395,48 kJ kg-1. PALAVRAS-CHAVE: Equilíbrio higroscópico, modelagem matemática, teor de água.Escola de Agronomia - Universidade Federal de Goiás2019-12-05info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionAvaliado por paresapplication/pdfhttps://revistas.ufg.br/pat/article/view/58128Pesquisa Agropecuária Tropical [Agricultural Research in the Tropics]; Vol. 50 (2020); e58128Pesquisa Agropecuária Tropical (Agricultural Research in the Tropics); Vol. 50 (2020); e58128Pesquisa Agropecuária Tropical; v. 50 (2020); e581281983-4063reponame:Pesquisa Agropecuária Tropical (Online)instname:Universidade Federal de Goiás (UFG)instacron:UFGenghttps://revistas.ufg.br/pat/article/view/58128/34022Copyright (c) 2019 Pesquisa Agropecuária Tropical (Agricultural Research in the Tropics)info:eu-repo/semantics/openAccessdos Santos, Samuel Gonçalves Ferreirada Silva, Daniel PereiraSarti, Jefferson KranAlmeida, Vinícius GonçalvesRodovalho, Renato Souza2020-02-28T14:14:39Zoai:ojs.revistas.ufg.br:article/58128Revistahttps://revistas.ufg.br/patPUBhttps://revistas.ufg.br/pat/oaiaseleguini.pat@gmail.com||mgoes@agro.ufg.br1983-40631517-6398opendoar:2024-05-21T19:56:26.765373Pesquisa Agropecuária Tropical (Online) - Universidade Federal de Goiás (UFG)true |
dc.title.none.fl_str_mv |
Adsorption isotherms and isosteric heat in Coffea arabica beans Isotermas de adsorção e calor isostérico em grãos de Coffea arabica |
title |
Adsorption isotherms and isosteric heat in Coffea arabica beans |
spellingShingle |
Adsorption isotherms and isosteric heat in Coffea arabica beans dos Santos, Samuel Gonçalves Ferreira |
title_short |
Adsorption isotherms and isosteric heat in Coffea arabica beans |
title_full |
Adsorption isotherms and isosteric heat in Coffea arabica beans |
title_fullStr |
Adsorption isotherms and isosteric heat in Coffea arabica beans |
title_full_unstemmed |
Adsorption isotherms and isosteric heat in Coffea arabica beans |
title_sort |
Adsorption isotherms and isosteric heat in Coffea arabica beans |
author |
dos Santos, Samuel Gonçalves Ferreira |
author_facet |
dos Santos, Samuel Gonçalves Ferreira da Silva, Daniel Pereira Sarti, Jefferson Kran Almeida, Vinícius Gonçalves Rodovalho, Renato Souza |
author_role |
author |
author2 |
da Silva, Daniel Pereira Sarti, Jefferson Kran Almeida, Vinícius Gonçalves Rodovalho, Renato Souza |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
dos Santos, Samuel Gonçalves Ferreira da Silva, Daniel Pereira Sarti, Jefferson Kran Almeida, Vinícius Gonçalves Rodovalho, Renato Souza |
description |
The knowledge of the adsorption hygroscopic equilibrium in coffee is pertinent for the adequacy of its storage, thus ensuring the quality of the product to the end consumer. The present study aimed to determine the adsorption isotherms of Arabica coffee (Acauã Novo cultivar) beans at the temperatures of 30 ºC, 40 ºC, 50 ºC and 60 ºC, as well as the integral adsorption isosteric heat. The equilibrium moisture contents were obtained by the gravimetric static method, using water activities between 0.10 and 0.83 (decimal). From the obtained data, several mathematical models were fitted to represent the adsorption isotherms. The statistical criteria for selecting the best model were the coefficient of determination, estimated mean standard error, relative mean error and distribution of residues. The Peleg model was the one that best represented the adsorption isotherms of the Arabica coffee beans under the studied conditions. The isotherms showed a sigmoidal type II shape. For a constant water activity, an increase in the temperature promotes a decrease in the equilibrium moisture content of Arabica coffee beans. In a moisture content range between 0.0191 and 0.2534 (dry base), the isosteric heat values ranged from 4,042.19 kJ kg-1 to 2,395.48 kJ kg-1. KEYWORDS: Hygroscopic equilibrium, mathematical modeling, moisture content. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-12-05 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Avaliado por pares |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://revistas.ufg.br/pat/article/view/58128 |
url |
https://revistas.ufg.br/pat/article/view/58128 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
https://revistas.ufg.br/pat/article/view/58128/34022 |
dc.rights.driver.fl_str_mv |
Copyright (c) 2019 Pesquisa Agropecuária Tropical (Agricultural Research in the Tropics) info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Copyright (c) 2019 Pesquisa Agropecuária Tropical (Agricultural Research in the Tropics) |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Escola de Agronomia - Universidade Federal de Goiás |
publisher.none.fl_str_mv |
Escola de Agronomia - Universidade Federal de Goiás |
dc.source.none.fl_str_mv |
Pesquisa Agropecuária Tropical [Agricultural Research in the Tropics]; Vol. 50 (2020); e58128 Pesquisa Agropecuária Tropical (Agricultural Research in the Tropics); Vol. 50 (2020); e58128 Pesquisa Agropecuária Tropical; v. 50 (2020); e58128 1983-4063 reponame:Pesquisa Agropecuária Tropical (Online) instname:Universidade Federal de Goiás (UFG) instacron:UFG |
instname_str |
Universidade Federal de Goiás (UFG) |
instacron_str |
UFG |
institution |
UFG |
reponame_str |
Pesquisa Agropecuária Tropical (Online) |
collection |
Pesquisa Agropecuária Tropical (Online) |
repository.name.fl_str_mv |
Pesquisa Agropecuária Tropical (Online) - Universidade Federal de Goiás (UFG) |
repository.mail.fl_str_mv |
aseleguini.pat@gmail.com||mgoes@agro.ufg.br |
_version_ |
1799874820495638528 |