Floral origin modulates the content of a lipid marker in Apis mellifera honey

The compound DAGE (DiAcyl Glyceryl Ether, 1-stearyl-2,3-dioleoyl glycerol), present in Apis mellifera honey, is a lipidic entomological marker secreted by the salivary glands of worker bees. Its content was determined by NMR, analyzing the organic extracts of a number of Italian honeys of different floral typology. We have found that the DAGE content is related to the botanical origin of honey. This dependence on floral typology was further confirmed by a linear correlation (R2 > 0.83) observed between the content of DAGE and the enzymatic activity of invertase and diastase in honey. Also these enzymes originate from bee salivary secretions and their concentrations in honey are known to depend on the floral source. DAGE content appears to be a sensitive parameter to some forms of honey manipulations, as indicated by the results of artificial bee-feeding experiments. This suggests its possible use as indicator of honey authenticity.