OPTIMIZATION OF EXTRACTION OF GREEN PROPOLIS PHENOLIC COMPOUNDS AND APPLICATION IN CHITOSAN BIOFILM

Propolis is a complex mixture produced by bees from various plant sources, exhibiting significant biological properties such as antioxidant, antibacterial, antiviral, and antifungal activities. Biofilms made from biodegradable polymers, incorporated with propolis extracts, present a promising alternative for developing food packaging materials. Since propolis is a resinous material with a high wax content, an extraction process is necessary to isolate the desired bioactive compounds. This study aimed to optimize the extraction process of phenolic compounds from propolis and apply them to chitosan biofilms produced by casting. The extracts were prepared based on an experimental design using mixtures of three solvents (water, ethanol, and ethyl acetate), resulting in 14 different formulations. By quantifying total phenolics, the optimal solvent ratio was determined to be 47.0% water, 35.0% ethanol, and 18.0% ethyl acetate. Subsequently, the optimized extract was incorporated into the biofilm. Characterization tests indicated no significant differences in thickness, water solubility, and water vapor permeability compared to the biofilm without the extract. Using optical and scanning electron microscopy, the homogeneity of the formed biofilms was confirmed, and it was established that the addition of the extract did not affect its microstructure. The incorporation of the extract into the biofilm demonstrated antioxidant potential, with the release of the extract into the medium yielding a DPPH value of 28.31 μmol Trolox L^-1 after 24 hours. Regarding the antimicrobial activity of the film, the release of the extract into the culture medium reduced proliferation of Staphylococcus aureus and Bacillus cereus. Therefore, it can be concluded that the extraction of phenolic compounds from propolis provides bioactive antioxidant and antimicrobial agents, and their incorporation into biofilms is feasible, offering potential applications in food packaging.