Estimation of Moisture Desorption Isotherms for Thompson Seedless Raisins and Determining the Best Appropriate Model

Moisture desorption isotherms are useful in food dehydration، storage and packaging. Due to the complex food composition، theoretical prediction of the isotherms is not possible and experimental measurements are necessary. Moisture desorption isotherms of Thompson seedless raisins were determined at 30، 40، 50، 60، 70 and 80 ºC، using the standard static gravimetric method developed by the European cooperation project COST 90. GAB، Smith، Oswin، Halsey، Henderson and D’Arcy- Watt equation were fit the data. The experimental data were fitted well with Halsey equation at 30 ºC and 40 to 80 ºC، with D’Arcy-Watt equation. So، Isosteric heat of desorption data obtained at different moisture content.