Parameters of the gross composition of propolis from Brazilian Meliponini

Propolis is a resinous and complex bee product containing resin derived from plants, beeswax, pollen and other minor constituents. The present study aimed to determine the parameters of the gross composition of propolis collected by nine stingless bee species from eight different Brazilian localities. The moisture content varied depending on the bee species and localities. Wax content enables us to distinguish between samples of <i>Melipona</i> and <i>Scaptotrigona</i>, samples of the former containing considerably less wax than samples of the latter genus. The ash content has an inverse trend, with samples of <i>Melipona</i> and <i>Scaptotrigona</i> having high and low ash content, respectively. The results indicated that <i>Melipona</i> species produce geopropolis (propolis containing aggregated soil material), while <i>Scaptotrigona</i> produces propolis devoid of soil, with the exception of <i>S. tubiba</i>. Most <i>Melipona</i> species collected sediments with high clay content. The size and color of ash crystals varied, mostly according to the locality of the meliponaries, although differences were observed between samples of the same species, growing in the same meliponary. Mineralogical analysis was relevant to determine that <i>M. flavolineata</i> from North Brazil aggregates river-bed soil sediments to the geopropolis.

蜂胶（Propolis）是一种树脂状且成分复杂的蜂产品，含有植物来源的树脂、蜂蜡、花粉及其他微量组分。本研究旨在测定从巴西8个不同地区采集的9种无刺蜂所产蜂胶的基本组成参数。

水分含量因蜂种与采集地区而异。蜂蜡含量可用于区分无刺蜂属（Melipona）与刺角蜂属（Scaptotrigona）的样品，前者的蜡含量显著低于后者。

灰分含量则呈现相反趋势：无刺蜂属样品的灰分含量偏高，而刺角蜂属样品的灰分含量偏低。

研究结果表明，无刺蜂属物种会产出地理蜂胶（geopropolis，即含有聚集土壤物质的蜂胶），而刺角蜂属物种除管状刺角蜂（S. tubiba）外，均产出不含土壤的蜂胶。

多数无刺蜂属物种会采集高黏土含量的沉积物。

灰分晶体的粒径与颜色主要因无刺蜂饲养场所在地而异，即便同一饲养场中同一物种的不同样品之间也存在差异。

矿物学分析证实，来自巴西北部的黄纹无刺蜂（M. flavolineata）会将河床土壤沉积物添加至其地理蜂胶中。