Chemometrics as a tool of origin determination of polish monofloral and multifloral honeys

The aim of this study was to evaluate the application of chemometrics studies to determine the botanical origin of Polish monofloral honeys using NMR spectroscopy. Aqueous extracts of six kinds of honeys, namely, heather (Calluna vulgaris L.), buckwheat (Fagopyrum esculentum L), lime (Tilia L), rape (Brassica napus L. var. napus), acacia (Acacia Mill.), and multifloral ones, were analyzed. Multivariate chemometric data analysis was performed using principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA). Chemometric analysis supported by pollen analysis revealed the incorrect classification of acacia honeys by the producers. Characteristic motives for each honey were identified, which allowed chemical profiles of tested honeys to be built. Thus, phenylacetic acid and dehydrovomifoliol (4-hydroxy-4-[3-oxo-1-butenyl]-3,5,5-trimethylcyclohex-2-en-1-one) were proposed to be markers of Polish heather honey. Formic acid and tyrosine were found to be the most characteristic compounds of buckwheat honey, whereas 4-(1-hydroxy-1-methylethyl)cyclohexane-1,3-dienecarboxylic acid was confirmed as a marker of lime honey.