title: Thin layer convective air drying of wild edible plant (Allium roseum) leaves: experimental kinetics, modeling and quality.
abstract: The present study deals with the valorization of an edible spontaneous plant of the Tunisian arid areas: Allium roseum. This plant is traditionally used for therapeutic and culinary uses. Thin-layer drying behavior of Allium roseum leaves was investigated at 40, 50 and 60 °C drying air temperatures and 1 and l.5 m/s air velocity, in a convective dryer. The increase in air temperature significantly affected the moisture loss and reduced the drying time while air velocity was an insignificant factor during drying of Allium roseum leaves. Five models selected from the literature were found to satisfactorily describe drying kinetics of Allium roseum leaves for all tested drying conditions. Drying data were analyzed to obtain moisture diffusivity values. During the falling rate-drying period, moisture transfer from Allium roseum leaves was described by applying the Fick's diffusion model. Moisture diffusivity varied from 2.55 × 10(-12) to 8.83 × 10(-12) m(2)/s and increased with air temperature. Activation energy during convective drying was calculated using an exponential expression based on Arrhenius equation and ranged between 46.80 and 52.68 kJ/mol. All sulfur compounds detected in the fresh leaves were detected in the dried leaves. Convective air drying preserved the sulfur compounds potential formation.
authors.affiliation: Department of Food Technology, National Institute of Agronomy of Tunisia, University of Carthage Laboratory of Economy, Sciences and Food technology, LR03AGR01 INAT, 43, Avenue Charles Nicolle, Tunis, Mahrajene 1082 Tunisia.
authors.forename: Leila
authors.initials: L
authors.lastname: Ben Haj Said
authors.affiliation: Range Ecology Laboratory, Institute of Arid Areas IRA, Medenine, 4119 Tunisia.
authors.forename: Hanen
authors.initials: H
authors.lastname: Najjaa
authors.affiliation: National Institute of Scientific and Technical Research, B.P. 95, Hammam Lif, 2050 Tunisia.
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Farhat
authors.affiliation: Range Ecology Laboratory, Institute of Arid Areas IRA, Medenine, 4119 Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Neffati
authors.affiliation: Department of Food Technology, National Institute of Agronomy of Tunisia, University of Carthage Laboratory of Economy, Sciences and Food technology, LR03AGR01 INAT, 43, Avenue Charles Nicolle, Tunis, Mahrajene 1082 Tunisia.
authors.forename: Sihem
authors.initials: S
authors.lastname: Bellagha
keywords: Activation energy; Allium roseum leaves; Drying kinetics; Modeling; Moisture diffusivity; Sulfur compounds