Drying Methods Affect the Drying Kinetics, Bioactive Characteristics and Essential Oil Composition of Lavender (Lavandula angustifolia Mill.) and Lavandin (Lavandula hybrida)

This study aimed effects of drying methods on drying kinetics, effective moisture diffusivity, color properties, total phenolic content, antiradical activity and essential oil composition of some selected lavender and lavandin genotypes. Six different genotypes developed by selection breeding at Erciyes University between 2017-2020 were used as plant materials grown under open-field conditions. Six different drying methods (convective, open-shade, open-sun, greenhouse, hybrid and freeze) were performed and compared. Statistical values showed that drying was best described by Wang & Singh mathematical model. Greenhouse drying was the fastest method in terms of drying duration. Freeze drying had relatively good color properties for lavender and lavandin flowers. The greatest effective moisture diffusivity values were obtained in hybrid drying and the lowest in greenhouse drying. The mean values of total phenolic content and antiradical activity of convective drying were statistically lower than from other drying methods. The highest essential oil ratios obtained in following drying methods with decreasing order: convective (5.10%), open-shade (4.65%), freeze (4.53%), open-sun (4.49%), greenhouse (4.33%) and hybrid (2.22%). The linalool ratio ranged between 27.16 to 79.21% and the highest value was obtained in the freeze-drying condition of the G208 genotype. In conclusion, open-shade drying method significantly positively affects bioactive characteristics and essential oil composition.