A targeted chemometric evaluation of the volatile compounds of Quercus ilex honey in relation to its provenance

Abstract The present study aimed at the determination of volatile compounds (VOCs) of Greek Quercus ilex honey, which comprises a rarely studied honeydew honey, from different regions and to characterize its provenance using a targeted chemometric evaluation of the semi-quantitative data of VOCs determined with headspace solid phase microextraction coupled to gas chromatography/mass spectrometry (HS-SPME/GC-MS). Principal component analysis (PCA), multivariate analysis of variance (MANOVA) and stepwise linear discriminant analysis (SLDA) showed that provenance affected the volatile composition of Quercus ilex honey. PCA explained 98.10% of total variance with the factors that maximized the squared cosine to be 10 VOCs: heptane, dimethyl-disulfide, octane, nonane, styrene, alpha-pinene, meta-cymene, dl -limonene, 1-decanol, and tetradecanoic acid ethyl ester. SLDA resulted in the formation of linear discriminant functions that provided a classification rate of honey samples according to provenance by ∼80%, based on styrene, eucalyptol, benzeneacetaldehyde, 1-decanol, and tetradecanoic acid ethyl ester. Considering the complementary results of PLS-VIP (partial least squares analysis-variable importance in projection) eucalyptol, 1-decanol, and tetradecanoic acid ethyl ester are proposed as volatile indicators of the provenance of Greek Quercus ilex honey. These VOCs were also correlated with the percent of Castanea sativa and Polygonum aviculare pollen grains.