Impact of genus (Geotrigona, Melipona, Scaptotrigona) on the targeted 1H-NMR organic profile, and authenticity test by interphase emulsion of honey processed in cerumen pots by stingless bees in Ecuador

Resumen

The biodiversity of Ecuadorian stingless bees is almost 200 species. Traditional pot-honey harvest in Ecuador is mostly done from nests of the three genera selected here <i>Geotrigona</i> Moure, 1943, <i>Melipona</i> Illiger, 1806, and <i>Scaptotrigona</i> Moure, 1942. The 20 pot-honey samples collected from cerumen pots and three ethnic honeys "abeja de tierra", "bermejo", and "cushillomishki" were analyzed for qualitative and quantitative targeted ¹H-NMR honey profiling, and for the Honey Authenticity Test by Interphase Emulsion (HATIE). Extensive data of targeted organic compounds (41 parameters) were identified, quantified, and described. The three honey types were compared by ANOVA. Amino acids, ethanol, hydroxymethylfurfural, aliphatic organic acids, sugars, and markers of botanical origin. The number of phases observed with the HATIE were one in <i>Scaptotrigona</i> and three in <i>Geotrigona</i> and <i>Melipona</i> honeys. Acetic acid (19.60 ± 1.45 g/kg) and lactic acid (24.30 ± 1.65 g/kg) were particularly high in <i>Geotrigona</i> honey (in contrast to 1.3 g/kg acetic acid and 1.6 g/kg lactic acid in <i>Melipona</i> and <i>Scaptotrigona</i>), and with the lowest fructose + glucose (18.39 ± 1.68) g/100g honey compared to <i>Melipona</i> (52.87 ± 1.75) and <i>Scaptotrigona</i> (52.17 ± 0.60). Three local honeys were tested using PCA (Principal Component Analysis), two were assigned with a correct declared bee origin, but "bermejo" was not a <i>Melipona</i> and grouped with the <i>Scaptotrigona</i> cluster. However after HCA (Hierarchical Cluster Analysis) the three honeys were positioned in the <i>Melipona</i>-<i>Scaptotrigona</i> cluster. This research supports targeted ¹H-NMR-based profiling of pot-honey metabolomics approach for multi-parameter visualization of organic compounds, as well as descriptive and pertained multivariate statistics (HCA and PCA) to discriminate the stingless bee genus in a set of <i>Geotrigona</i>, <i>Melipona</i> and <i>Scaptotrigona</i> honey types. The NMR characterization of Ecuadorian honey produced by stingless bees emphasizes the need for regulatory norms. A final note on stingless bee markers in pot-honey metabolites which should be screened for those that may extract phylogenetic signals from nutritional traits of honey. <i>Scaptotrigona vitorum</i> honey revealed biosurfactant activity in the HATIE, originating a fingerprint Honey Biosurfactant Test (HBT) for the genus in this set of pot-honeys.