Enthalpy-entropy compensation based on isotherms of mango

Food Science and Technology (Campinas)

Javier Telis-romero²  Márcio N. Kohayakawa¹  Vivaldo Silveira Jr¹  Maria A. M. Pedro²  Ana L. Gabas¹ 

[1] ,Universidade Estadual Paulista Depto. de Engenharia e Tecnologia de Alimentos São José do Rio Preto SP

关键词: moisture content;    thermodynamic properties;    mango;    umidade;    propriedades termodinâmicas;    manga;   

DOI  :  10.1590/S0101-20612005000200020

来源: SciELO

【 摘 要 】

Moisture equilibrium data of mango pulp were determined using the static gravimetric method. Adsorption and desorption isotherms were obtained in the range of 30-70 ºC, to water activities (a w) from 0.02 to 0.97. The application of the GAB model to the experimental results, using direct nonlinear regression analysis, provided 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 deltaH versus deltaS provided the isokinetic temperatures, indicating an enthalpy controlled sorption process.

【 授权许可】

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