Antioxidant Activity, Total Phenolic Content, and Volatile Component Profiles of Propolis From Eight Turkish Regions

This study aimed to evaluate the volatile component profiles and antioxidant activities of propolis samples collected from eight regions of Türkiye. The total phenolic content of propolis samples was found to vary between 5333 and 36967 mg GAE/100 g. 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity of the samples varied from 10.9% to 92.2%, while 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activity varied from 193.8 to 1026.0 µmol Trolox/g. Six of the eight samples exhibited higher antioxidant activities than butylated hydroxytoluene. The predominant volatile components identified in the majority of the propolis samples were α-pinene, limonene, bornyl acetate, caryophyllene, α-humulene, δ-cadinene, isopentyl acetate, acetic acid, nonanal, m-cymene, and pinocarvone. Principal component analysis (PCA) and hierarchical cluster analyses were applied to the GC-MS data to investigate the trends and clustering in the propolis samples. The propolis samples were divided into four groups using cluster analysis. In the PCA, the first two factors represented 56.39% of the variance. These findings revealed that Turkish propolis has significant antioxidant properties and also contains important volatile compounds. Consequently, Turkish propolis could be considered a potential candidate for incorporation into pharmaceutical and food products.