Results
The PERMANOVA showed significant differences between honey samples from
stingless bees and honey bees (p-value = 0.001, df = 1,
R2 = 0.230). Our NMDS plot (Fig. 2) illustrated these
differences, showing a clear general distinction between the two
discrete clusters of samples. The composition of a few samples did not
follow this pattern and had opposite characteristics, resulting in a
small number of errors (4 out of 75 samples) for stingless bees in the
classifications of the conditional random forest models. Major
fermentation markers (acetic and lactic acid) and sugars (fructose and
glucose) were recorded in all honeys, and they were the most relevant
compounds to discriminate the two groups of honeys. Stingless bee honeys
had lower sugars levels and higher fermentation marker levels than honey
bees samples. The amino acid levels also varied significantly among our
samples independently of the bee taxa. Finally, our indicator compounds
analysis showed no significant association between bee taxa and a
specific compound.