TURK 2025

In this study, we aimed to determine optimal drying conditions to preserve the quality characteristics of Foxtail lily (Eremurus spectabilis M. Bieb.) with minimal quality loss. This wild edible medicinal and aromatic plant belongs to the Liliaceae family and is geographically distributed across South and Central Asia (Iran, Western Pakistan, Afghanistan, Iraq, Palestine, Lebanon, Syria, the Caucasus, and Turkey). It is rich in vitamin C and B3, reduced glutathione (GSH), flavonoids, fiber, and microelements, making it valuable both for various industrial applications and in traditional folk medicine due to its antioxidative and antimicrobial properties. The thin-layer drying characteristics of Foxtail lily (Eremurus spectabilis M. Bieb.) were investigated using microwave drying technique. Drying experiments were conducted at different microwave power levels (90, 360, 600, and 800 W), and the drying kinetics of the plant were examined throughout the process. Additionally, thermal color degradation occurring during microwave drying was investigated. In the color space: L represents luminosity/brightness, with values ranging from 0 (black) to 100 (white). The color parameters “a” and “b” represent red and yellow at positive values, and green and blue at negative values [±a (red-green), ±b (yellow-blue)]. Experimental parameters related to color change were evaluated, and these parameters were used to calculate total color change (ΔE), chroma value (CV), hue angle, and browning index (BI). During microwave drying, L, b, chroma, and hue angle values decreased, while a, ΔE, and BI values increased. It was determined that microwave drying occurred primarily in the falling rate period. Increasing the microwave power level resulted in reduced drying time. The effective diffusion coefficients (Deff) were calculated using Fick’s Diffusion Model, with effective diffusivity values ranging from 6.65×10⁻⁷ to 4.67×10⁻⁶ m²/s. An Arrhenius-type exponential function was employed as a mathematical model to determine the activation energy, which was calculated to be 7.31 W·g⁻¹.