Characterization of commercially available propolis products in Turkey based on individual phenolic compounds

Abstract

The healing properties of propolis, such as antibacterial, antiviral, antifungal, anti-inflammatory, antitumoral, antioxidant, immunomodulatory, tissue regeneration, and anti-ulcer, are due to the high content of phenolic compounds (flavonoids and phenolic acids). Therefore, propolis can potentially be used for human consumption or even for medicinal purposes. This study aimed to analyze sixteen individual phenolic compounds that have beneficial effects, determine their concentrations in local and imported raw propolis and products consumed in Turkey, and evaluate the determined results for propolis quality. A total 91 propolis samples were collected from commercial raw propolis and propolis products, which were from different provinces of Turkey and different countries, sold and used in Turkey between 2015 and 2018. Sixteen phenolic compounds were analyzed by high-performance liquid chromatography with a diode array detector system. Regardless of their origin, the results indicated that the concentrations of individual phenolic compounds varied greatly within crude, ethanol-based, water-based, and propylene glycol propolis samples analysed. There were significant differences in some individual phenolic compounds between the local and imported samples (p < 0.05). The current results showed that qualitative and quantitative analysis of commercial propolis samples for useful phenolic compounds are important and may provide quality control of propolis products.