Phytochemical Profile and Bioactive Potential of Quercus suber L. Cork Extract for Dermocosmetic Applications

Skin aging is closely associated with oxidative stress and extracellular matrix (ECM) degradation, driving the search for multifunctional natural ingredients capable of targeting both processes. This study investigated cork powder, a by-product of Quercus suber L. processing, as a source of bioactive compounds for dermocosmetic applications through the characterization and functional evaluation of its phenolic extract. Phytochemical characterization confirmed a substantial phenolic fraction, while HPLC–DAD–ESI-MS/MS analysis enabled the tentative identification of characteristic cork phenolics, including ellagitannins and ellagic acid. The extract exhibited antioxidant activity in DPPH, ABTS, and FRAP assays, together with pronounced hyaluronidase inhibition (97.12 ± 8.17%), moderate elastase inhibition (41.44 ± 3.29%), and comparatively limited tyrosinase inhibition. Following incorporation into cream, lip balm, and cleansing gel formulations, measurable antioxidant activity was retained, although its magnitude varied according to formulation type and antioxidant assay. Enzyme-inhibitory activity was also retained in the cream, with estimated IC50 values of approximately 0.6% for hyaluronidase and 1.75% for elastase. No evident deterioration in the measured mechanical and organoleptic characteristics was observed over the two-month storage period. Overall, cork powder extract demonstrated potential as a multifunctional dermocosmetic ingredient combining antioxidant and ECM-associated enzyme-inhibitory properties while contributing to the higher-value valorization of a cork-processing by-product.