Water Desorption and Thermodynamic Properties of Okra Seeds
André L. D. Goneli, Paulo César Côrrea, Gabriel Henrique Horta de Oliveira, Fernando Mendes Botelho
Transactions of the ASABE
Abstract
The objective of the present work was to determine desorption isotherms of okra seeds for diverse conditions of temperature (10C to 50C) and relative humidity (0.11 to 0.96) of the air, as well as determine the values of isosteric heat of desorption, differential entropy, and Gibbs free energy. To obtain the equilibrium moisture content, a static method was used. Experimental data were adjusted to frequently used mathematical models for representation of hygroscopicity of agricultural products. Calculation of the net isosteric heat of desorption was performed based on the Clausius-Clapeyron thermodynamic relation. From the obtained results, it was concluded that equilibrium moisture content of the okra seeds decreased with an increase in temperature at the same relative humidity, as is the case of the majority of agricultural products. Based on statistical parameters, the Chung-Pfost model best represented the hygroscopicity of the okra seeds. Values of the integral isosteric heat of desorption as well as the differential entropy and Gibbs free energy for the okra seeds decreased with an increase in moisture content.
Extracted Claims
3 claims extracted from this paper into the knowledge graph
Chung-Pfost model best represented the hygroscopicity of the okra seeds
“Based on statistical parameters, the Chung-Pfost model best represented the hygroscopicity of the okra seeds.”
integral isosteric heat of desorption, differential entropy, and Gibbs free energy decreased with an increase in moisture content
“Values of the integral isosteric heat of desorption as well as the differential entropy and Gibbs free energy for the okra seeds decreased with an increase in moisture content.”
equilibrium moisture content of okra seeds decreased with an increase in temperature at the same relative humidity
“equilibrium moisture content of the okra seeds decreased with an increase in temperature at the same relative humidity, as is the case of the majority of agricultural products.”