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

Author(s)

Ferreira de Souza, Silvio Jose ^[1] ; Alves, Aline Inacio ^[2] ; Rufino Vieira, Erica Nascif ^[2] ; Gomez Vieira, Jose Antonio ^[1] ; Ramos, Afonso Mota ^[2] ; Telis-Romero, Javier ^[1]

Affiliation

^[1] Univ Estadual Paulista, UNESP, Dept Engn & Tecnol Alimentos, Sao Jose Do Rio Preto, SP - Brazil

^[2] Univ Fed Vicosa, Dept Tecnol Alimentos, Vicosa, MG - Brazil

• Document type: Journal article
• Source: FOOD SCIENCE AND TECHNOLOGY; v. 35, n. 1, p. 157-166, JAN-MAR 2015.
• Web of Science Citations: 2

Abstract

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 degrees C 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. (AU)

• FAPESP's process: 13/17497-5 - Determination of the best conditions of physical hydrolysis by power ultrasound in agroindustrial wastes
• Grantee: Javier Telis Romero
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants