Evaluation of honey quality of Northeast of Brazil: botanical origin and heavy metals content

A chemical and palynological study was performed on honey of Apis mellifera L. (Hymenoptera: Apidae) produced and marketed in the nine states that comprise the Northeast Region of Brazil. A total of 58 samples were obtained from markets between the years 2015 and 2017. The pollen spectra of the samples encompassed 232 pollen types of defined botanical origin, with 31 samples possessing predominant pollen in their spectra, which represent species with beekeeping potential: Angelonia, Borreria verticillata, Copaifera, Mimosa caesalpiniifolia, M. pudica, M. tenuiflora, Myrcia 1, Schinus terebinthifolia, Tapirira guianensis, Tarenaya, and Ziziphus joazeiro. Leguminosae was the most represented botanical family in all the studied honey samples, with Mimosa L. being the most diverse and frequent genus. The richness of different pollen types varied among states, but similarities in pollen spectra were minimally related to geographical proximity to the municipalities of origin. Thus, some pollen types, alone or in combination, can be considered good indicators of honey produced in Northeast Brazil. The levels of the main metallic contaminants of honey (i.e., As, Cd, Cr, Hg, and Pb) were found to be below their respective limits, suggesting that honey samples from the Northeast are safe for human consumption. The studied samples presented heterogeneous botanical constitutions that reflect the diversity of plant species of the Caatinga biome and the generalist habit of A. mellifera.