PHYSICOCHEMICAL CHARACTERIZATION AND FUNCTIONAL COMPOUNDS OF IN NATURE AND MATURED HONEYS FROM MELIPONA SUBNITIDA AND MELIPONA SCUTELLARIS

Stingless bee honey (SBH) has characteristics that differ from those of Apis mellifera honey, notably a higher moisture content and greater acidity, which favour the activity of microorganisms that promote fermentation. In this context, post-harvest maturation may induce changes that influence the quality, stability and functional composition of this honey. The aim of this study was to evaluate the influence of post-harvest maturation on the physicochemical characteristics, bioactive compound content and antioxidant activity of honeys from Melipona subnitida and Melipona scutellaris. In natura and matured honeys, matured at room temperature for nine months, were evaluated for pH, acidity, total soluble solids (TSS) and moisture content. Total phenolic and flavonoid contents were also determined, as well as antioxidant capacity using the FRAP, DPPH and ABTS assays. The results for in natura and matured honeys were subjected to Student’s t-test (p < 0.05). Maturation significantly altered the physicochemical parameters, increasing acidity in both species from 23.08 to 38.69 and from 38.06 to 77.61 in M. subnitida and M. scutellaris honeys, respectively. The pH decreased from 3.58 to 3.21 in matured M. subnitida honey, whereas no significant difference was observed in M. scutellaris honey (p ≥ 0.05). TSS content in M. subnitida samples also decreased, from 73.07 to 69.83 °Brix, whereas that of M. scutellaris remained constant (71.83%). Maturation affected moisture content differently between the species: M. subnitida honey increased from 24.92 to 27.96 g/100 g, whereas M. scutellaris honey decreased from 17.77 to 16.66 g/100 g. Regarding bioactive compounds, a significant reduction in phenolic and flavonoid contents was observed in M. subnitida honey, from 92.45 to 40.99 mg GAE/100 g and from 22.55 to 4.12 mg quercetin equivalents/100 g, respectively. Fresh M. scutellaris honey had a phenolic content of 117.92 mg GAE/100 g, with a reduction of 29.85 mg GAE/100 g following maturation. Antioxidant capacity showed different patterns depending on the assay used. For M. subnitida honey, maturation significantly reduced ABTS values from 394.21 to 281.97 µmol TEAC/100 g, DPPH values from 48.95 to 21.94 µmol TEAC/100 g, and FRAP values from 176.86 to 63.97 µmol TEAC/100 g. For M. scutellaris samples, ABTS antioxidant activity decreased from 554.18 to 473.50 µmol TEAC/100 g, whereas FRAP increased from 206.23 to 243.86 µmol TEAC/100 g, and DPPH remained close to 100 µmol TEAC/100 g. These results show that maturation induces changes that vary according to bee species. These findings reinforce the need to establish appropriate parameters for the maturation process to preserve the bioactive compounds and the distinctive characteristics of honey from each stingless bee species.