Flavonoid patterns of French honeys with different floral originC. Soler, M.I. Gil, C. García-Viguera and F.A. Tomás-Barberán
Laboratorio de Fitoquímica, Departamento de Ciencia y Technología de los Alimentos, CEBAS (CSIC), PO Box 4195, Murcia 30080, Spain
Abstract - The flavonoid profiles of 12 different unifloral French honey samples were analysed by HPLC to evaluate if these substances could be used as markers of the floral origin of honey. In this analysis, the characteristic flavonoids from propolis and/or beeswax (chrysin, galangin, tectochrysin, pinocembrin and pinobanksin) were separated from those originating mainly from nectar and/or pollen (polyhydroxylated flavonoid aglycones), which would be related to their floral origin. All the analysed samples contained a common flavonoid profile consisting of polyhydroxylated flavonoid aglycones including 8-methoxykaempferol, kaempferol, quercetin, isorhamnetin, luteolin and apigenin, suggesting that flavonoid analysis does not generally prove differences between French monofloral honey samples. However, some individual honey samples showed potential floral markers. Thus, heather honey was characterized by the presence of myricetin, calluna honey by ellagic acid and citrus honey by the flavanone hesperetin. In other samples, the relative amount of 1 individual flavonoid could be related to the floral origin. Thus, sunflower honeys contained an important relative amount of quercetin, and in alder honey only 8-methoxykaempferol was detected. This preliminary study shows that flavonoid and phenolic compound analyses could be a very valuable complementary biochemical technique in the objective determination of the floral origin of some specific monofloral honey samples, but further studies with a larger number of samples is necessary to confirm the observed differences.
Key words: honey / flavonoid / botanical origin / HPLC