Evaluation of thermodynamic properties using GAB model to describe the desorption process of cocoa beans
The desorption isotherms and thermodynamic properties of cocoa beans were obtained during the drying process of this product. The isotherms were determined by dynamic method for various temperature (25, 35,45 and 55 C) and relative humidity (RH) conditions (30, 40, 50, 60, 70 and 80%). Equilibrium m...
| Autores: | , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2011 |
| País: | Brasil |
| Recursos: | Universidade Federal de Viçosa (UFV) |
| Repositorio: | LOCUS Repositório Institucional da UFV |
| Idioma: | inglés |
| OAI Identifier: | oai:locus.ufv.br:123456789/22428 |
| Acesso em linha: | https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2621.2011.02719.x http://www.locus.ufv.br/handle/123456789/22428 |
| Access Level: | acceso abierto |
| Palavra-chave: | Entropy Gibbs free energy Isosteric heat Monolayer moisture content Theobroma cacao |
| Resumo: | The desorption isotherms and thermodynamic properties of cocoa beans were obtained during the drying process of this product. The isotherms were determined by dynamic method for various temperature (25, 35,45 and 55 C) and relative humidity (RH) conditions (30, 40, 50, 60, 70 and 80%). Equilibrium moisture content data were correlated by the Guggenheim–Anderson–de Boer (GAB) model, which presented good fit to the data, according to statistical procedures. Equilibrium moisture content ranged from 5.90 to 16.67 d.b.; it increased with an increment in the RH and decreased with increased temperature at a constant RH.Enthalpy values for each model coefficient were encountered, ranging from )90.05 to 545.96 kJ kg )1 . The integral isosteric heat of desorption and differential entropy increased with decreased equilibrium moisture content, a tendency also found for Gibbs free energy. |
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