Study of thermodynamic water properties and moisture sorption hysteresis of mango skin

Silvio José  Ferreira de SOUZA; Aline  Inácio ALVES; Érica  Nascif Rufino VIEIRA; José Antônio  Gomez VIEIRA; Afonso  Mota RAMOS; Javier  TELIS-ROMERO

Study of thermodynamic water properties and moisture sorption hysteresis of mango skin

Autores

Silvio José Ferreira de SOUZA

Aline Inácio ALVES

Érica Nascif Rufino VIEIRA

José Antônio Gomez VIEIRA

Afonso Mota RAMOS

Javier TELIS-ROMERO

Editor

Sociedade Brasileira de Ciência e Tecnologia de Alimentos

Descripción

The equilibrium moisture content for adsorption and desorption isotherms of mango skin was determined using the static gravimetric method at temperatures of 20, 26, 33, 38 and 44 oC in the 0.056 to 0.873 water activity range. Both sorption curves show a decrease in equilibrium moisture content as the temperature increasing. The hysteresis effect was observed at constant water activity. The Guggenheim, Anderson, and de Boer (GAB) model presented the best fitting accuracy among a group of models and was used to determine the thermodynamic properties of water sorption. Integral enthalpy and integral entropy areas showed inverted values for the adsorption and desorption isotherms over the wide range of water activity studied. These values confirm, in energetic terms, the difference between adsorption and desorption isotherms observed in the hysteresis phenomenon. Finally, the Gibbs free energy revealed that the sorption process was spontaneous for both sorption isotherms.