Phytochemical Screening and Physicochemical Properties of Oil Extract of Usnea barbata L. F.H.Wigg from Călimani Mountains, Romania

Green cosmetics are mainly based on plant-derived ingredients, using sustainable bio-technological tools for their preparation. The present research aimed to investigate the Usnea barbata extract in Jojoba oil (JO) enriched with 10% Vitamin E and 5% Pepper-mint oil (PEO), as a potential natural product for skin applications. Materials and Methods: The U. barbata extract (UBPJO) was obtained through cold maceration. Phytochemical screening was performed using Gas Chromatography/Mass Spectrometry (GC-MS), Folin Ciocalteu method, and Graphite-Furnace Atomic Absorption Spectro-photometry. The physicochemical properties were evaluated by Fourier Transform Infrared Spectroscopy and Atomic Force Microscopy. Then, rheological characteristics and oxidation stability (measuring the time required to reach the oxidation starting point, IP) of both oil samples (PJO and UBPJO), were investigated. Results: Total phenolic content in UBPJO was 2.5 times higher than in PJO (p < 0.05), while heavy metal levels (As and Pb) were slightly higher (p > 0.05). UBPJO has higher shear stress, viscosity, and spreadability than PJO, but without significant differences (p > 0.05). Finally, IP measurements indicated appreciable oxidative stability (UBPJO vs. PJO: 153.02 h vs 137.35 h, p > 0.05). Conclusions: The phytochemical composition and physicochemical properties support the inclusion of UBPJO in various skin-protective formulations.