Modeling of the Equilibrium Moisture Content (EMC) of Tarragon (Artemisia Dracunculus L.)

The equilibrium moisture content of tarragon, Artemisia dracunculus L. ( stem and leaf separately) was determined by using the saturated salt solutions method at three temperatures ( 25, 50 and 70 degrees C) within a range of 5 to 90% relative humidity. Both adsorption and desorption methods were used for stem and leaf of two varieties: Russian and French tarragon. Experimental curves of moisture sorption isotherms were fitted by modified Henderson, modified Halsey, modified Oswin, modified Chung-Pfost and GAB equations and evaluated by residual sum squares, standard error of estimate and mean relative deviation. The modified Halsey and GAB equations were found to be the most suitable for describing the relationship among equilibrium moisture content, relative humidity and temperature. There was no significant difference between the equilibrium moisture content of the Russian and French tarragon.