13th Conference on Medicinal and Aromatic Plants of Southeast European Countries (CMAPSEEC 2026)

Essential oils obtained from medicinal and aromatic plants are widely recognized for their antimicrobial and antioxidant properties. However, the essential oils recovered from industrial processing by-products remain largely unexplored despite their potential contribution to circular bioeconomy and sustainable valorization of agro-industrial residues. This study evaluated the chemical composition and biological activity of essential oils extracted from industrial residues of three medicinal and aromatic plant species: Origanum vulgare subsp. hirtum, Satureja montana, and Salvia officinalis. Chemical characterization was performed by gas chromatography–mass spectrometry (GC–MS), while antioxidant activity was determined using the DPPH and ABTS radical scavenging assays. Antimicrobial activity was assessed by determining the minimum inhibitory concentrations (MIC) against six pathogens.
The essential oils retained the characteristic chemical profiles reported in the literature, with oregano oils dominated by carvacrol, savory oils by thymol, and sage oils by camphor. Likewise, the antioxidant and antimicrobial activities were generally consistent with those described for conventionally extracted essential oils, indicating that industrial processing residues preserve a substantial proportion of the biologically active constituents responsible for these properties. Where applicable, the chemical composition also showed good agreement with the compositional ranges established by international standards. The results demonstrate that essential oils recovered from industrial processing residues retain high concentrations of bioactive constituents and significant biological properties despite originating from by-products.
These findings highlight the considerable potential of medicinal and aromatic plant processing residues as a sustainable source of value-added essential oils for applications in food, pharmaceutic and cosmetic industries, supporting waste valorization and circular economy strategies.