Comparative analysis of Rosmarinus officinalis L. essential oil and hydrosol

Rosmarinus officinalis L. (rosemary) is a well-known herb with strong antioxidant and anti-inflammatory properties [ 1 ]. Traditionally used to improve circulation and reduce inflammation, it is widely studied for its potential in treating diseases related to oxidative stress and inflammation. Although most research focuses on its essential oil, studies on both the essential oil and hydrosol remain limited [ 2 ] [ 3 ]. This study compares the quality and effectiveness of self-extracted and commercial rosemary products. The total phenolic content of a commercially available R. officinalis L. essential oil was compared with that of a hydrosol obtained via steam distillation using a Clevenger apparatus. Plant material was collected from Istanbul during flowering season in 2024. While hydrosol was successfully obtained, essential oil yield was too low for experimental use. Therefore, analyses at this stage were conducted on the hydrosol and a commercial essential oil. The total phenolic content of the hydrosol was determined using the Folin-Ciocalteu method as 27.19±16.01 mg GAE/g, whereas the commercial essential oil showed 57.98±13.23 mg GAE/g, where GAE refers to gallic acid equivalents. This preliminary investigation aims to contribute to the understanding of the pharmacognostic potential of Turkish rosemary and presents part of the initial findings from a research project developed within the scope of an undergraduate thesis proposal. Further analyses will assess total flavonoid content, DPPH scavenging activity, CUPRAC antioxidant capacity, and anti-inflammatory effects of both product types. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany