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.

本研究针对巴西东北部九个州生产并销售的西方蜜蜂（Apis mellifera L.，膜翅目：蜜蜂科）蜂蜜开展了化学与孢粉学分析。研究于2015至2017年间从市场共采集58份蜂蜜样品。样品的花粉谱涵盖232种经确定植物来源的花粉类型，其中31份样品的花粉谱中存在优势花粉，对应11个具备养蜂价值的物种：翅茎草属（Angelonia）、轮生博纳草（Borreria verticillata）、香脂木豆属（Copaifera）、含羞草（Mimosa caesalpiniifolia）、敏感含羞草（M. pudica）、细叶含羞草（M. tenuiflora）、桃金娘属类群1（Myrcia 1）、巴西乳香（Schinus terebinthifolia）、圭亚那重阳木（Tapirira guianensis）、醉蝶花属（Tarenaya）、巴西枣（Ziziphus joazeiro）。所有受试蜂蜜样品中，豆科（Leguminosae）为占比最高的植物科，而含羞草属（Mimosa L.）则是多样性与出现频率最高的属。不同花粉类型的丰富度在各州间存在差异，但花粉谱的相似性与原产地市镇的地理邻近性相关性极低。因此，部分花粉类型单独或组合使用时，可作为巴西东北部产区蜂蜜的良好标识物。蜂蜜中主要金属污染物（即砷As、镉Cd、铬Cr、汞Hg及铅Pb）的含量均低于各自的限值标准，表明巴西东北部产区的蜂蜜样品可供安全食用。本次研究的样品呈现出多样化的植物组成，这既反映了卡廷加生物群系（Caatinga）的植物物种多样性，也体现了西方蜜蜂的广食性觅食习性。