Comparative Evaluation of Physical and Phenolic Profiles in Propolis from N. Macedonian Regions

Aims/Objective: Propolis, a resinous substance collected by bees from plants, is an exceptionally complex mixture whose quality is influenced by the surrounding flora, geography, and climate. It has been used medicinally for centuries and is currently utilized in natural foods, pharmaceuticals, and cosmetics. The aim of this study was to measure the physical parameters and total phenolic content of ethanolic extracts of propolis (EEP). The study also involved a step-by-step approach to ensure maximum extraction efficiency. The experimental design incorporates detailed procedures for freezing, micronization, and filtration, which ensure the precision and reproducibility of the results. The study's use of standardized techniques, such as the Folin-Ciocalteu colorimetric assay for the determination of total phenolic content, further validates the accuracy of the findings. Study Design: Comparative experimental study. Place and Duration of Study: Between April and July 2024, suitable ethanolic propolis extracts (4% and 10%) were prepared from raw propolis collected from two different regions (Pelagonia and Polog). Methodology: Physical parameters such as solubility, conductivity and yield were analyzed in these extracts. Two subsequent extractions, each with two replicates, were performed on the same samples to obtain initial insights into achieving the highest yield from a given amount of propolis. The total phenolic content in the EEP was determined using the Folin-Ciocalteu colorimetric method, with results expressed as mg GAE/g. Results: Conductivity, yield, and solubility measurements varied across Pelagonia (42 ppm, 17.42%, high solubility) and Polog (33 ppm, 15.38%, lower solubility) propolis extracts, reflecting diverse chemical profiles influenced by geographical factors. Regional analysis of propolis from Pelagonia and Polog regions revealed significant differences in total phenolic content, with Pelagonia extracts showing higher values (189 mg GAE/g) compared to Polog (172 mg GAE/g). Statistical tests confirmed these differences as significant (p < 0.05), underscoring the impact of geographic origin on propolis composition. Conclusions: Variations in bioactive content in propolis are influenced by geographical origin, botanical sources, and extraction methods. Standardized extraction protocols and further research are crucial for optimizing its medicinal potential and utilizing insoluble propolis solids.