The palynology of purple honey: kudzu dismissed, aluminum-sourwood reaction and other sources behind color plausible

Abstract

Here we present the palynological composition of a single sample of the elusive purple honey collected in southern North Carolina and discuss how it fits within a nearby statewide South Carolina melissopalynological study. 302 samples were collected by nineteen beekeepers participating in this year-long project, submitting honey samples while honeybees were actively collecting nectar. The absence of pollen of Pueraria (kudzu) in the purple honey dismisses the often-suggested link between the unique tint of the purple honey and kudzu’s purple pollen. A second hypothesis hinting that the tint could be linked to ripened berries is not reinforced by our investigation as pollen of Ericaceae (eg blueberries) and Rosaceae (eg blackberries) were not found in the purple honey sample but were commonly found in classic golden honey analyzed. The presence of Vitis pollen supports the possibility that bees forage on wild muscadine grapes (Vitis rotundifolia) which was available in the foraging area. This study cannot discredit the possibility that bees were foraging on berry juices or other sugar sources containing purple pigments because these sources contain little or no pollen. A third hypothesis proposes a link between purple honey and the sourwood tree, Oxydendrum arboretum. This hypothesis is supported by this investigation as the dominant pollen type recovered in the purple honey was sourwood, with 19% in relative abundance, a significant percentage for this plant. We suggest chemical analysis of purple honey samples be conducted to determine if berry juice or sourwood is the more likely source of the pigmentation.