Assessment of Essential Oil Yield from Artemisia herba-alba and the Endemic Artemisia mesatlantica in the Middle Atlas of Morocco: A Step Toward Sustainable Valorization

Species of the genus Artemisia play a central role in Moroccan traditional pharmacopoeia and aromatic plant exploitation; however, several endemic taxa remain poorly documented in terms of their physicochemical and productive potential. This study presents a comparative evaluation of Artemisia herba-alba and the endemic Artemisia mesatlantica collected from the Middle Atlas region, with a specific focus on moisture content and essential oil yield under standardized post-harvest and extraction conditions. Aerial parts were harvested in April following AFNOR (NF T 75-402) standards, dried using both solar and controlled-temperature oven methods, and subjected to hydrodistillation using a Clevenger-type apparatus. The two species exhibited marked quantitative differences in water content. A. herba-alba showed a low average moisture content of 8.3% (range: 4.63–16.12%), whereas A. mesatlantica displayed significantly higher values averaging 23.5% (range: 20.71–25.81%), reflecting contrasting tissue hydration and water-retention capacities. Essential oil yields were low for both taxa, reaching 0.14 ± 0.01% for A. herba-alba and 0.16 ± 0.01% for A. mesatlantica on a dry-mass basis. Despite the modest absolute yields, A. mesatlantica consistently exhibited slightly higher values, even in the context of elevated moisture levels, suggesting potential anatomical or physiological specificities influencing volatile compound production and storage. These results emphasize the strong sensitivity of Artemisia essential oil production to ecological context, phenological stage, and post-harvest handling. Furthermore, they provide valuable baseline data for the future phytochemical characterization, bioactivity assessment, and sustainable valorization of the endemic A. mesatlantica within Moroccan medicinal and aromatic plant sectors.