Volatile composition of Anatolian propolis by headspace-solid-phase microextraction (HS-SPME), antimicrobial activity against food contaminants and antioxidant activity

Abstract

Propolis is an important natural resource utilized by humans since ancient times. It is a resinous mixture containing polyphenols, mainly flavonoids and phenolic acids as well as volatile compounds. Propolis has been used for its antibacterial, antifungal, antiviral, antineoplastic, antioxidant, immunomodulating and antiinflammatory properties. Ethanol extracts of three different propolis samples collected from North East Anatolia were chemically and biologically evaluated. Volatile compounds of the samples were analysed by headspace-solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The main volatile constituents were identified as phenyl ethyl alcohol (7.7%), benzyl alcohol (7.4%), decanal (6.7%), ethyl benzoate (6.5%), nonanal (5%) and cedrol (4.1%) for the Yesilyurt propolis; cedrol (15.6%) for Sarıcicek propolis and α-bisabolol (14.3%), cedrol (7%), δ-cadinene (5.6%) and α-eudesmol (3.6%) for the propolis from Erzincan, respectively. The best antioxidant activity with IC50 value of 4.95 µg/ml was defined using the spectroscopic (1,1-diphenyl-2-picryl-hydrazyl) radical scavenging assay. The highest antimicrobial activity was determined by agar dilution method against the pathogen Bacillus cereus (0.06 to 0.12 mg/ml). Propolis could be a salubrious additive for the production and protection of functional foods having a microbial deterioration potential.   Key words: Propolis, headspace-solid-phase microextraction (HS-SPME), antimicrobial activity, antioxidant activity, functional food, volatile compounds.