Composition, antioxidant and antibacterial properties of Rosmarinus officinalis L. essential oils from Mostaganem, Algeria: Regional valorisation perspective

Abstract

The objective of this study is to characterize the chemical profile and evaluate the antibacterial and antioxidant properties of Rosmarinus officinalis L. essential oil (REO) from the Mostaganem region, Algeria. The EO was extracted from leaves and flowers by hydro distillation, yielding 0.62%. Physicochemical analyses revealed an acid index of 2.24 and an ester index of 325.10, confirming compliance with AFNOR quality standards.GC-MS allowed the identification of 15 major constituents (92.56% of total oil), notably 1,8-cineole, camphor, and α-pinene. Antibacterial activity was assessed against Staphylococcus strains using agar-diffusion assays, with inhibition zones reaching 21 mm. Antioxidant capacity, measured by the DPPH radical-scavenging test, demonstrated moderate activity (64%). Special emphasis is placed on the regional agro-economic relevance of REO, illustrating its potential to diversify agricultural production under challenging climates. The results further address practical applications in agri-food sectors including its use as a natural preservative, aromatic ingredient, and functional additive. Standardized protocols ensure methodological reproducibility and facilitate transferability to other agricultural contexts.