To select and establish floral
biomarkers of the botanical origin of Diplotaxis tenuifolia honeys, the
flavonoids and
glucosinolates present in bee-deposited
nectar collected from hive combs (unripe honey) and mature honey from the same
hives fron which the unripe honey samples were collected were analyzed by LC-UV-PAD-ESI-MS(n). Glycosidic conjugates of the
flavonols quercetin,
kaempferol, and
isorhamnetin were detected and characterized in unripe honey. D. tenuifolia mature honeys contained the aglycones
kaempferol,
quercetin, and
isorhamnetin. The differences between the phenolic profiles of mature honey and freshly deposited honey could be due to hydrolytic enzymatic activities. Aliphatic and
indole glucososinolates were analyzed in unripe and mature honeys, this being the first report of the detection and characterization of
glucosinolates as honey constituents. Moreover, these honey samples contained different amounts of
propolis-derived
flavonoid aglycones (1765-3171 μg/100 g) and
hydroxycinnamic acid derivatives (29-1514 μg/100 g).
Propolis flavonoids were already present in the freshly deposited
nectar, showing that the incorporation of these compounds to honey occurs at the early steps of honey production. The
flavonoids quercetin,
kaempferol, and
isorhamnetin and the
glucosinolates detected in the samples could be used as complementary
biomarkers for the determination of the floral origin of Argentinean Diplotaxis honeys.