Characterization, Classification and Authentication of Spanish Blossom and Honeydew Honeys by non-targeted HPLC-UV and off-line SPE HPLC-UV Polyphenolic Fingerprinting Strategies.

Abstract

Honey is a highly consumed natural product produced by bees which is susceptible to fraudulent practices, some of them regarding their botanical origin. Two HPLC-UV non-targeted finger-printing approaches were evaluated in this work to address honey characterization, classification, and authentication based on honey botanical variety. The first method used no sample treatment and a universal reversed-phase chromatographic separation. On the contrary, the second method was based on an off-line SPE preconcentration method, optimized for the isolation and extraction of polyphenolic compounds, and a reversed-phase chromatographic separation opti-mized for polyphenols as well.. For the off-line SPE method, the use of HLB (3 mL, 60 mg) car-tridges, and 6 mL of methanol as eluent, allowed to achieve acceptable recoveries for the selected polyphenols. The obtained HPLC-UV fingerprints were subjected to exploratory principal com-ponent analysis (PCA) and classificatory partial least squares-discriminant analysis (PLS-DA) to evaluate their viability as sample chemical descriptors for authentication purposes. Both HPLC-UV fingerprints resulted to be appropriate to discriminate between blossom-honeys and honeydew-honeys. However, superior performance was accomplished with off-line SPE HPLC-UV polyphenolic fingerprints, being able to differentiate among the different blos-som-honey samples under study (orange/lemon blossom, rosemary, thyme, eucalyptus, and heather). In general, this work demonstrated the feasibility of HPLC-UV fingerprints, especially those obtained after off-line SPE polyphenolic isolation and extraction, to be employed as honey chemical descriptors to address the characterization and classification of honey samples according to their botanical origin.