Experimental determination of the sorption isotherms of mint (Mentha viridis), sage (Salvia officinalis) and verbena (Lippia citriodora)

Mint (Mentha viridis), verbena (Lippia citriodora) and sage (Salvia officin alis) are the most produced and consumed aromatic herbs in Morocco. The sor ption isotherms of the three plants were determined within the range of 10- 90% relative air humidity at three different temperatures (25 degreesC, 40 degreesC and 50 degreesC), using saturated salt solutions method. Henderson 's equation was fitted to the experimental data and the agreement between e xperimental and calculated values was satisfactory. The comparison between the sorption isotherms of mint, verbena and sage is studied. (C) 2000 Elsev ier Science Ltd. All rights reserved.