Thermodynamic properties applied to the sorption isotherms of kiwifruit

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Data

2001-01-01

Autores

Kohayakawa, M. N.
Yamashita, F.
Telis-Romero, J.
Gabas, A. L.

Título da Revista

ISSN da Revista

Título de Volume

Editor

Isnt Tecnologico Veracruz

Resumo

The net isosteric heat and entropy of water sorption were calculated for kiwifruit, based on sorption isotherms obtained by the static gravimetric method at different temperatures (20 to 70 degreesC). The Guggenheim-Anderson-deBoer equation was fitted to the experimental data, using direct non-linear regression analysis; the agreement between experimental and calculated values was satisfactory. The net isosteric heat of sorption was estimated from equilibrium sorption data, using the Clausius-Clapeyron equation. Isosteric heats of sorption were found to increase with increasing temperature and could be well adjusted by an exponential relationship. The enthalpy-entropy compensation theory was applied to sorption isotherms and plots of DeltaH versus DeltaS provided the isokinetic temperature, T-B = 450.9 +/- 7.7 K, indicating an enthalpy-controlled desorption process over the whole range of moisture content considered.

Descrição

Palavras-chave

heat of sorption, enthalpy, entropy, isotherms, kiwifruit

Como citar

Proceedings of the Second Inter-american Drying Conference. Veracruz 91860: Isnt Tecnologico Veracruz, p. 453-462, 2001.