Amazonian Native Palm Fruits as Sources of Antioxidant Bioactive Compounds

The Amazon region has many sources of fruits, especially native ones not yet explored, but which have some potential for use, as is the case with certain palms. The objective of this study was to evaluate the content of bioactive compounds and total antioxidant capacities of fruits from native palms from the Brazilian Amazon. The fruits of five palm species (bacaba, buriti, inajá, pupunha, and tucumã) were evaluated for levels of ascorbic acid, anthocyanins, yellow flavonoids, total carotenoids, and total extractable polyphenols, as well as the total antioxidant capacities. The fruits had high contents of extractable total polyphenols, especially bacaba and tucumã (941.56 and 158.98 mg of galic acid·100g−1), total carotenoids in the case of tucumã and buriti (7.24 and 4.67 mg·100g−1), and anthocyanins in bacaba (80.76 mg·100g−1). As for the antioxidant capacity, bacaba had the highest total antioxidant activity by the Oxygen Radical Antioxidant Capacity (ORAC) (194.67 µM·Trolox·g−1), 2,2-diphenyl-1-picrylhydrazyl (DPPH) (47.46 g·pulp·g−1 DPPH), and β-carotene/linoleic acid (92.17% Oxidation Inhibition (O.I) methods. Bacaba phenolic profile revealed the presence of cyanidin-3-O-rutinoside and other flavonoids. The palm fruits studied can be considered good sources of bioactive compounds, some containing higher amounts than that of commonly consumed fruits. Total extractable polyphenols and anthocyanins were directly correlated to antioxidant activity in these fruits.