Solvent-Driven Extraction of Bioactive Compounds from Propolis for Application in Food Industry Matrices

Abstract

Propolis is a resinous substance collected by honeybees from plant exudates and enriched with beeswax, pollen, and enzymes. Known for its antioxidant, antimicrobial, and anti-aging properties, it has attracted interest for applications in food, nutraceutical, and cosmetic industries. In this work, Portuguese propolis from the Guarda region was characterized to evaluate how different solvents influence extraction efficiency and bioactive potential. Samples were extracted by cold maceration using 96% ethanol, 70% ethanol, and ultrapure water, and their physicochemical profile was determined. Total phenolic content (TPC) and total flavonoid content (TFC) were measured by the Folin–Ciocalteu and aluminum chloride methods, while antioxidant activity was assessed through DPPH, ABTS, and FRAP assays. Tyrosinase and elastase inhibition tests were performed to assess anti-aging potential. Ethanolic extracts contained markedly higher phenolic and flavonoid levels than aqueous extracts, with 70% ethanol showing a slight advantage for flavonoid recovery. Both TPC and TFC correlated strongly with antioxidant activity (R2 > 0.95), highlighting phenolics, particularly flavonoids, as the main contributors to bioactivity. The 96% ethanol extract showed the highest tyrosinase inhibition (46.9 ± 0.9%), while elastase inhibition remained consistently high for ethanolic extracts. Overall, these findings indicate that Portuguese propolis is a rich source of bioactive compounds and emphasize the importance of solvent selection to optimize its functional properties.