Otro
Water sorption thermodynamic properties applied to persimmon skin and pulp
Registro en:
Thermochimica Acta, v. 343, n. 1-2, p. 49-56, 2000.
0040-6031
10.1016/S0040-6031(99)00379-2
WOS:000084693100008
2-s2.0-0002138370
0000-0002-2553-4629
Autor
Telis, V. R. N.
Gabas, A. L.
Menegalli, F. C.
Telis-Romero, J.
Resumen
Moisture equilibrium data of persimmon skin and pulp were determined using the static gravimetric method. Adsorption and desorption isotherms were obtained in the range of 20-70°C, to water activities (a w) from 0.02 to 0.85. The application of the GAB model to the experimental results, using direct nonlinear regression analysis, provided a good agreement between experimental and calculated values. 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 ΔH versus ΔS for skin and pulp provided the isokinetic temperatures, indicating an enthalpy controlled sorption process. © 2000 Elsevier Science B.V.