GAB model and the thermodynamic properties of moisture sorption in soursop fruit powder

Experimental Investigation of Moisture Sorption Isotherms for Mefenamic Acid Tablets

“…The GAB model can be used over a wide range of water activity up to 0.9; its application is more advantageous than other models since its parameters have physical meanings allowing a detailed study of mass and heat transfer that occur during desorption-adsorption processes [4, 5, 16 and 25]. From the results shown in Table .4, the GAB constants were temperature dependent that agreed with [22,28].…”

“…for desorption and (20.73 to 14.52 % d.b.) for adsorption and that explained due to the gained kinetic energy by the molecules which caused to loosen the attractive forces, allowing some molecules of the water to break away from their sorption sites, also a reduction in the number of active sites and decrease in the available specific surface area that caused to decrease the M m that agreed with [4,5,22,23].…”

“…The increase was a result of the strong binding of water monolayer with the primary sorption sites; the temperature increase caused a gain in kinetic energy which increase enthalpy and more moisture loss at a higher temperature. The values of C for desorption were higher than that for adsorption, which means the water monolayer removal from the structure of the material required more heat [22,27].…”

“…At M m, the physical changes, oxidation, and degradation are slow down. Changes occur when the moisture content value of a product is lower than M w [1,22]. It is generally decreased with temperature and that agreed with [7,23,27].…”

Valorisation of rice straw by obtaining active compounds and cellulosic materials for the development of biodegradable food packaging systems

“…This behaviour indicates that water molecules adsorb irregularly in multilayers with no prevalent monolayer adsorption, and there was no water capillary condensation in the pores in the studied range, since this phenomenon would occur at higher water activity (aw>0.95) (Aviara, 2020). The experimental data were modelled by fitting the GAB equation, which is applicable over a wide range of aw values (Baptestini et al, 2020). Fig.…”