Revealing the Potential of Artemisia sp. Hydrosols: Chemical Composition and Valorization of Essential Oil Byproducts from Four Varieties

Hydrosols, also referred to as hydrolates, are valuable yet underutilized byproducts of essential oil distillation. They consist of residual essential oil compounds combined with water-soluble phytochemicals, many of which exhibit notable biological activities. Research has demonstrated antimicrobial effects - including the inhibition of biofilm formation - as well as antioxidant properties that counteract oxidative stress. These biofunctional features make hydrosols attractive for diverse applications: in agriculture as biopesticides, in food preservation as natural additives and anti-browning agents, in pharmaceuticals as antimicrobial or antitumor agents, and in cosmetics as bioactive ingredients. The present study focuses on the chemical profile of hydrosols derived from four Artemisia species and evaluates their potential uses. Water distillation remains the dominant extraction method, accounting for around 93% of global essential oil production, typically performed via hydro-distillation or steam distillation. This process generates two phases: the essential oil and its aqueous counterpart, the hydrosol. Analytical results confirmed the presence of key compounds such as trans-pinocarveol, 1.8-cineole, and spathulenol, supporting their multifunctional properties. Overall, these findings highlight hydrosols as sustainable natural products with promising roles across multiple industries. From a circular economy perspective, valorizing such byproducts enhances resource efficiency and provides environmentally friendly alternatives to conventional synthetic additives.