Floral quality and discrimination of Lavandula stoechas, Lavandula angustifolia, and Lavandula angustifolia×latifolia honeys

Portuguese lavender honeys are generated from the nectar of Lavandula stoechas, whereas French lavender honeys are exclusively derived from Lavandula angustifolia, Lavandula latifolia, or hybrids of these two species. In the framework of the floral origin authentication of such honeys, volatile compounds from L. stoechas, L. angustifolia, and L. angustifolia×latifolia unifloral honeys were investigated. The aromatic profiles of French and Portuguese lavender honey samples showed major qualitative and quantitative differences, but no volatile compound is characteristic of L. stoechas honeys only. As expected, n-hexanal, n-heptanal, phenylacetaldehyde, and n-hexanol, previously proposed to authenticate French lavender honeys, were found at concentrations far above the published discrimination thresholds. Coumarin, previously proposed to characterize French lavender honeys, emerges here rather as an indicator of the freshness of lavender honey, being mainly released from glycosides during storage. Lastly, L. angustifolia honeys were distinguishable from hybrid-derived samples by their lower phenylacetaldehyde and higher heptanoic acid content.