Supercritical CO2-based tailor made valorization of Origanum vulgare L extracts: A green approach to extract high-value compounds with applied perspectives.

In this study, the supercritical CO₂-based extraction approach was used from the green technologies to extract Oregano oil (Origanum vulgare L.). A Taguchi experimental design was applied to evaluate the effect of pressure, temperature and ethanol as co-solvent. High yield of oregano oil (13.40%) was obtained at 40 °C, 100 bar and 8 g min^-1 of co-solvent flow. Fatty acids profile include α-linolenic, palmitic, oleic and linoleic that contribute to 70.9-76.8% of total fatty acids. Volatile compounds including carvacrol (29.99%), heneicosane (8.21%), nonacosane (11.78%), docosane (7.18%), borneol (4.35%) and thymol (4.51%) were the main compounds identified. Antimicrobial activity assays showed that extracts obtained at 40 °C were highly efficient against S. aureus, E. coli, and C. albicans. Highest antioxidant activities on DPPH and FRAP assays were reached under 8 g min^-1 of co-solvent flow (6.08 and 6.89 μmol TE g^-1 extract, respectively). On the other hand, antioxidant activity (35.76 μmol TE g^-1) on ABTS assay was improved at 40 °C, 100 bar, and 4 g min^-1 of co-solvent flow.