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Eryngium foetidum L. is an edible plant widespread in Amazonian cuisine and its leaves have high levels of promising phenolic compounds for the production of extracts to be used as natural antioxidant additives. In this study, the in vitro scavenging capacity of three freeze-dried extracts of E. foetidum leaves, obtained by ultrasound-assisted extraction using green solvents [water (H2O), ethanol (EtOH), and ethanol/water (EtOH/H2O)], was investigated against the most common reactive oxygen species (ROS) and reactive nitrogen species (RNS) generated in both physiological and food systems. Six phenolic compounds were identified, chlorogenic acid (2198, 1816 and 506 μg/g) being the major compound for EtOH/H2O, H2O, and EtOH extracts, respectively. All E. foetidum extracts were efficient in scavenging all the ROS and RNS (IC50 = 45–1000 µg/mL), especially ROS. The EtOH/H2O extract showed the highest contents of phenolic compounds (5781 μg/g) and showed the highest efficiency in scavenging all the reactive species, with high efficiency for O2•− (IC50 = 45 μg/mL), except for ROO•, for which EtOH extract was the most efficient. Therefore, E. foetidum leaf extracts, especially EtOH/H2O, showed high antioxidant potential to be used as natural antioxidants in food formulations and are promising for nutraceuticals products.

In this work, we present a preparative elution method by high-speed countercurrent chromatography (Prep-HSCCC) for the separation and isolation of the main bioactive xanthones present in the alcoholic extract of Garcinia mangostana L. agro-industrial waste. The method proved to be quite efficient, operating with a two-phase solvent system consisting of Methanol/water/Ethanol/Hexane/methyl tert-butyl ether (6:3:1:6:4v/v), tail-head elution mode, with mobile phase flow of 5 mL/min and rotation speed of 800 rpm. The method demonstrated repeatability (RSD = 3.8–6.5%) and allowed the isolation of α-mangostin and γ-mangostin xanthones, both with purities above 93%, in a single step, performed in a time of 35 min. Isolated substances were identified by HPLC-PDA-MS and 1H and 13C NMR spectroscopy. Both xanthones were efficient scavengers of DPPH·· and ABTS·+ radicals in a concentration-dependent manner with EC50 at 8.43 and 3.31 µg/mL, respectively, for γ-mangostin, and 71.10 and 29.33 µg/mL, respectively, for α-mangostin.

Arrabidaea chica, a medicinal plant found in the Amazon rainforest, is a promising source of bioactive compounds which can be used to inhibit oxidative damage in both food and biological systems. In this study, the in vitro scavenging capacity of characterized extracts of A. chica leaves, obtained with green solvents of different polarities [water, ethanol, and ethanol/water (1:1, v/v)] through ultrasound-assisted extraction, was investigated against reactive oxygen (ROS) and nitrogen (RNS) species, namely superoxide anion radicals (O2•−), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), and peroxynitrite anion (ONOO−). The extract obtained with ethanol–water presented about three times more phenolic compound contents (11.8 mg/g) than ethanol and water extracts (3.8 and 3.6 mg/g, respectively), with scutellarein being the major compound (6.76 mg/g). All extracts showed high scavenging efficiency against the tested ROS and RNS, in a concentration-dependent manner with low IC50 values, and the ethanol–water extract was the most effective one. In addition, all the extracts were five times more efficient against ROO• than Trolox. Therefore, the extracts from A. chica leaves exhibited high promising antioxidant potential to be used against oxidative damage in food and physiological systems.

This study aimed to identify the volatile compounds in the fermented and dried cocoa beans conducted with three distinct inoculants of yeast species due to their high fermentative capacity: Saccharomyces cerevisiae, Pichia kudriavzevii, the mixture in equal proportions 1:1 of both species, and a control fermentation (with no inoculum application). Three starter cultures of yeasts, previously isolated and identified in cocoa fermentation in the municipality of Tomé-Açu, Pará state, Brazil. The seeds with pulp were removed manually and placed in wooden boxes for the fermentation process that lasted from 6 to 7 days. On the last day of fermentation, the almonds were packaged properly and placed to dry (36 °C), followed by preparation for the analysis of volatile compounds by GC-MS technique. In addition to the control fermentation, a high capacity for the formation of desirable compounds in chocolate by the inoculants with P. kudriavzevii was observed, which was confirmed through multivariate analyses, classifying these almonds with the highest content of aldehydes, esters, ketones and alcohols and low concentration of off-flavours. We conclude that the addition of mixed culture starter can be an excellent alternative for cocoa producers, suggesting obtaining cocoa beans with desirable characteristics for chocolate production, as well as creating a product identity for the producing region.