Chemical and bioactive characterization of Euterpe oleracea Mart
Artigo de Conferência
Visão geral
Pesquisas
Informação adicional documento
Ver Todos
Visão geral
resumo
Besides the economic factor, açaí has been highlighted for its nutritional value, but also for its richness in α-tocopherol (vitamin E), phenolic compounds and for having interesting bioactive potential1. Therefore, the objective of this work was to perform the chemical and bioactive characterization of freeze-dried açaí pulp. Organic acids were determined by HPLC-DAD, tocopherols by HPLC-fluorescence, and phenolic compounds using HPLC-DAD-ESI/MS. The antioxidant potential was assessed through cellular antioxidant activity (CAA), thiobarbituric acid reactive substances (TBARS), and radical scavenging activity (DPPH) assays; the antimicrobial capacity was evaluated using the microdilution method against pathogenic microorganisms, cytotoxicity against tumoral and non-tumoral cell lines by the sulphorhodamine B assay, and the anti-inflammatory potential using RAW cells.
Citric acid (3.36 ± 0.07 g/100 g DW) was the most abundant organic acid, being fumaric acid found in the lowest concentrations (0.0117 ± 0.0001 g/100 g DW). Alpha and beta tocopherols were identified, with contents of 0.046 ± 0.001 mg/100 g DW and 0.17 ± 0.12 mg/100 g DW, respectively. Regarding the phenolic composition, taxifolin-O-deoxyhexylhexoside was the main compound (4.34 ± 0.03 mg/g of extract), followed by sinapoyl hexoside (2.27 ± 0.04 mg/g), quercetin-3-O-rutinoside (2.21 ± 0.06 mg/g) and finally isorhamnetin-3-O-rutinoside (0.54 ± 0.02 mg/g), presenting a total of non-anthocyanin phenolic content of 9.36 ± 0.15 mg/g of extract. Also, five anthocyanin compounds were identified, totaling 11.99 ± 0.22 mg/g of extract, where the compounds cyanidin-3-O-glucoside (4.72 ± 0.20 mg/g) and cyanidin-3-O-rutinoside (4.54 ± 0.03 mg/g) presented the highest levels, with lower, but significant, contents for pelargonidin-3-O-rutinoside (0.60 ± 0.01 mg/g).
For the antioxidant potential, EC50 values of 270 ± 5 μg/mL in the DPPH and 61 ± 2 μg/mL in the TBARS assays, and 61% of oxidation inhibition at 2000 μg/mL in the CAA assay were obtained. Concerning the antimicrobial capacity, tested against food borne and clinical pathogens, the açaí extract was more active against Gram positive bacteria, with inhibition concentrations ranging from 1.25 to 10 mg/mL. As for cytotoxicity, the extract revealed activity against breast carcinoma cells (MFC-7) with IC50 values of 255 ± 22 μg/mL, while no significant effect was found against lung carcinoma cells (NCI-H460) and the normal cell culture (PLP2), for which values above the maximum concentration tested were found (>400 μg/mL). The extract also revealed anti-inflammatory activity with EC50 values of 384 ± 11 μg/mL.
Taking in consideration the results obtained in the range of analyses performed, it can be concluded that the açaí pulp is an interesting source of bioactive molecules, highlighting its the antioxidant activity. Therefore, this fruit could be exploited for the development of functional formulations, besides being a candidate to explore as a natural source of colouring or preservative agents.
