The Effect of Granulometry and Hydrodistillation Time for Volatile Oils from Melipona quadrifasciata Geopropolis

This work aims to evaluate the effect of granulometry and hydrodistillation time on the yield and chemical composition of Melipona quadrifasciata geopropolis. A sample obtained in southern Brazil was ground, separated into three different particle size groups (< 180 μm; 180 to 355 μm; and 356 to 1.70 mm), and subjected to hydrodistillation in a Clevenger apparatus for 2, 3, and 4 h. The volatile oils were characterised by GC-MS and quantified by GC-FID. The smallest granulometry provided the highest yield (0.48 ± 0.01%) in 4 h of hydrodistillation, and the differences in chemical composition were only quantitative, with α-pinene identified as the major constituent. With thin/very thin granulation, the extraction of more complex molecules such as sesquiterpenes was less effective. Evidently, it is important to standardise the pre-treatment of the geopropolis and the conditions of the hydrodistillation process to optimise the extraction of the desired volatile oils. Graphical Abstract