Headspace, volatile and semi-volatile patterns of Paliurus spina-christi unifloral honey as markers of botanical origin

The samples of unifloral Paliurus spina-christi honey were analysed by means of headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) followed by gas chromatography and mass spectrometry (GC, GC–MS) in order to obtain complete patterns of headspace, volatile and semi-volatile compounds. In headspace pattern the most abundant compounds and possible markers were nonanal, four isomers of lilac aldehyde, decanal, methyl nonanoate, hexanoic and 2-ethylhexanoic acids. Although the main components of USE extracts were higher saturated aliphatic hydrocarbons, higher aliphatic alcohols and acids, they can not be considered reliable biomarkers due to their probable origin from bee wax or bee cuticle. Although present in small quantities, the more reliable markers in the extracts were benzene derivatives (particularly 4-hydroxy-3,5-dimethylbenzaldehyde, 4-hydroxybenzoic acid and 4-methoxybenzoic acid) along with lower aliphatic acids (butanoic, hexanoic, octanoic and nonanoic).