Adsorption isotherms and isosteric heat in Coffea arabica beans
| Autor: | Samuel Gonçalves Ferreira dos Santos, Daniel Pereira da Silva, Jefferson Kran Sarti, Vinícius Gonçalves Almeida, Renato Souza Rodovalho |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Hygroscopic equilibrium Coefficient of determination Water activity Moisture Chemistry Agriculture (General) Coffea arabica mathematical modeling Thermodynamics 04 agricultural and veterinary sciences 01 natural sciences Equilibrium moisture content S1-972 Adsorption hygroscopic equilibrium 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Gravimetric analysis Agronomy and Crop Science Water content 010606 plant biology & botany moisture content |
| Zdroj: | Pesquisa Agropecuária Tropical v.50 2020 Pesquisa Agropecuária Tropical Universidade Federal de Goiás (UFG) instacron:UFG Pesquisa Agropecuária Tropical, Vol 50, p e58128 (2019) |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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