Thermo-hygroscopic characterization of Arthrospira Platensis by DVS

Abstract The objective of this work was to examine the thermo-hygroscopic behavior of Arthrospira (Spirulina) platensis using dynamic vapor sorption (DVS) system. This thermo-hygroscopic analysis focused on three parameters: desorption isotherms, the net isosteric heat of water desorption and moisture diffusivity. Desorption isotherms were performed at temperatures of 25°C, 40°C, 50°C, 60°C and 80°C across a relative humidity range of 10 to 80%. The desorption isotherm data were fitted to five semi-empirical models: GAB; Oswin; Smith; Henderson and Peleg. The results indicated that the GAB model provided the best fit for the desorption isotherm data. The net isosteric heat of desorption decreased from from 21.3 to 4.29 KJ/mol as the moisture content increased from 0.02 to 0.1 Kg/Kg (dry basis). Additionally, the moisture diffusivity of Arthrospira platensis moisture diffusivity ranged from 1.04 10− 8 m2/s to 1.46 10− 7 m2/s for average moisture contents varying from 0.003 Kg /Kg to 0.191 Kg /Kg (dry basis).