Estudo químico e potencial biológico de mel e propólis de Scaptotrigona depilis

Abstract

Products made by bees have always aroused interest, either for the therapeutic benefits or for the pleasant taste of honey as a culinary additive. Over the years, the application of these products became wider, in cosmetics, pharmaceuticals and nutritionals, whose properties were better defined. Chemical characterization is a fundamental part of understanding their benefits and uses. In view of the above, this study aims to determine the chemical composition of honey subjected to different treatments, and of the propolis produced by Scaptotrigona depilis. For the study of the composition of propolis, samples were collected in colonies of S. depilis, created in the meiponário of Embrapa Meio Ambiente, in Jaguariúna-SP, from which extracts were prepared with 70% ethyl alcohol (EEP70) and cereal alcohol (EPAC ). Extracts were analyzed by LC-ESI-MS/MS. In natura propolis was also subjected to the extraction of volatiles by hydrodistillation, which were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). In addition, assays were performed to determine the antimicrobial activity against pathogens of clinical interest. Regarding honey, treatments were carried out: pasteurization, dehumidification, refrigeration and maturation for 180 days. Fresh honey as well as treated honeys were extracted from honey volatiles by headspace technique in dynamic mode, using Porapak-Q with nitrogen gas flow, the extracted compounds were characterized by GC-MS. Phenolics were quantified by the Folin-Ciocalteu method and flavonoids with aluminum chloride, in addition, the antioxidant activity was determined by the DPPH free radical scavenging method of the treated and in natura honeys. Sensory analysis tests were also carried out, through the analysis of ordering-preference and acceptance using the hedonic ladder, with untrained tasters. The volatile constituents present in propolis belong to the class of sesquiterpenes. In the propolis extracts, the chromatographic profiles showed that the EEP70 extract presents a greater number of signals. After data analysis in appropriate software, through ensemble analysis using the Venn diagram, a greater quantity of unique chemical entities was observed in EEP70. Through Molecular Networking (MN) it was possible to suggest the presence of different classes of compounds, in which the most representative were terpenes with errors below 5 ppm. The ethanolic extracts of Scaptotrigona depilis propolis showed antimicrobial activity against Echerichia coli and Staphylococcus aureus. The analyzes of honey volatiles suggest different profiles after treatment over 180 days. The phenolic content did not change significantly over the period of analysis, and consequently its antioxidant activity did not change either. The sensory analysis showed that only the attributes color, flavor and overall appearance showed significant differences between matured and in natura honey and, despite this, the greatest preference is for in natura honey. The study is an important contribution to research with products made by this species of bee and may support the regulation and standardization of the processing of honey from stingless bees.