Metabolic Study of Dioecy in Mauritia flexuosa: NMR-based and Chemometric Approaches

Bioactive compounds, phenolic profile, antioxidant capacity and effectiveness against lipid peroxidation of cell membranes of Mauritia flexuosa L. fruit extracts from three biomes in the Ecuadorian Amazon

The bioactive compounds, total antioxidant capacity and protective effect against lipid oxidative damage of red blood cell (RBC) membranes of Mauritia flexuosa L. extracts from three altitude levels (low, middle and high zones) were analyzed. The identification of the main polyphenols in the fruit was performed using High Performance Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry analysis, while High-Performance Liquid Chromatography - Diode Array Detector was applied for the vitamin C and carotenoid analysis. The ability of the extracts (methanolic, free polyphenols and bound polyphenols) to protect RBC membranes against oxidative destruction was assessed utilizing the thiobarbituric acid reactive substance assay (TBARS) assay. Among the 14 phenolic compounds identified, quercetin glycosides were the most predominant ones. The fruit from the middle altitude zone showed higher vitamin C and lutein contents than those from the low and high areas, whilst higher values of β-Carotene were obtained in M. flexuosa L. from the low zone. The contents of flavonoids and total polyphenols were lower in fruit from the low zone, whilst the fruit from the middle zone had the highest values. Similar results were observed in the results of the antioxidant capacity assays. However, a significant difference was not found in the protective effect of the extracts from the three altitude zones against lipid peroxidation in RBC membranes.

Improvement of the bioaccessibility of bioactive compounds from Amazon fruits treated using high energy ultrasound

The aim of this paper was to evaluate the effect of high energy ultrasound on the bioaccessibility of bioactive compounds from açaí (Euterpe precatoria) and buriti (Mauritia flexuosa) juices. Five levels of energy density (0, 0.9, 1.8, 2.7 and 3.6 J.cm^-3), as well as their effects on the bioactive compounds were evaluated. Ultrasound did not significantly influence pH, titratable acidity and soluble solids. However, it affected the color attributes of juices by increasing brightness and color variation. The concentration of bioactive compounds (anthocyanins and carotenoids) and antioxidants increased with increasing ultrasound energy density, which was confirmed by Principal Component Analysis (PCA). Fatty acids increased up to 2.7 J.cm^-3 and were reduced when higher energy was employed on the ultrasound process. Ultrasound allowed the release of new aromatic substances. For this reason, the ultrasound technology can be considered an alternative pre-treatment for fruit juices, improving the bioaccessibility and concentration of bioactive compounds.