A study of pollen from light honeys produced in Piauí State, Brazil

Abstract

Colour is one of the features that differentiate the types of honeys, perhaps the attribute that has the most power of attractiveness to consumers, who tend to value light honeys. Nevertheless, there is no research to date showing the botanical origin of light honeys from Piauí, and neither separating them from the dark ones, using the pollen spectrum. Aiming to characterise botanical origin from pollen grains, samples of light honey produced in the state of Piauí, and also investigating the possibility of differentiation between light and dark honey through pollen spectrum analysis, 26 samples classified as light by spectrophotometry (≤50 mm Pfund), along with six dark samples, were acetolised with adaptation of solution/rinsing with ethanol. Following that, the pollen residue was analysed under an optical microscope. The obtained data were subjected to ordination through a principal coordinate analysis and a detrended correspondence analysis. A total of 151 pollen types were identified in samples of light honeys, representing 41 botanical families, three of which are noteworthy: Euphorbiaceae, Fabaceae and Rubiaceae. Among the types present in 50% or more of the samples, and the highest relative frequency, the following are significant: Mimosa caesalpiniifolia, Mimosa pudica, Mimosa tenuiflora/verrucosa, Pityrocarpa moniliformis and Syagrus. Of the 26 analyzed samples of light honey, 13 were considered monofloral: seven of P. moniliformes, five of M. caesalpiniifolia and one of M. pudica. The ordering analysis revealed the existence of groups between light honeys, two of which are unrelated to dark honeys. Plants of the Fabaceae family, especially the genera Mimosa and Pityrocarpa, contribute greatly to the production of light honeys in Piauí State, Brazil.