Production of propolis and geopropolis by stingless bees

Abstract

Propolis is a resinous product produced by honey bees (Apis mellifera) with plant exudates or buds, to which they aggregate beeswax. Most stingless bees (meliponines) produce propolis in ways similar to honey bees. Several meliponines include soil in their propolis, with the effect that the final mass and volume of the product is increased. For this reason, meliponine propolis is in general called geopropolis. In the present work propolis of two meliponines native in Brazil, Melipona marginata and Scaptotrigona xanthotricha, were analyzed for determination of the contents of moisture, ashes, wax, total phenols and sequestering activity. The content of ashes of propolis of M. marginata was very high (73.66%), indicating that the product, in fact, contains soil. On the contrary, the content of ashes of S. xanthotricha (1.99%) is comparable with the ash content of propolis of honey bees. Thus, the propolis of S. xanthotricha does not contain soil, and thus, in this case, the designation geopropolis is not appropriate. The contents of the wax of propolis were 1.44% for M. marginata and 28.82% for Scaptotrigona. These results suggest opposed strategies adopted by meliponines, with the consequence of enlarging propolis volume and mass. The strategies are an aggregation of either soil (M. marginata) or wax (S. xanthotricha). The contents of total phenols for both species were low, below the minimum admitted by Brazilian official rules. Coherent with the content of total phenols, the sequestering activity also was lower for propolis of both species.