Characterization of the Antioxidant and Bioactive Potential of Bacaba (Oenocarpus bacaba Mart.), an Amazonian Fruit of Interest to the Food Industry

The Amazon is home to a wide diversity of native fruit species with potential applications in the food industry and other technological fields. Among them, bacaba (Oenocarpus bacaba Mart.) stands out for its traditional consumption and its potential as a source of bioactive compounds. Characterizing its antioxidant properties may contribute to the valorization of this raw material and support the development of higher-value food ingredients. In this context, this study aimed to evaluate the total phenolic and flavonoid contents and the antioxidant capacity of bacaba pulp using different in vitro methods. The pulp was obtained by processing the fruits with water to simulate their traditional form of consumption, followed by freeze-drying and storage at −20 °C in the absence of light. The compounds were extracted in triplicate using a mixture of ethanol, acetone, and water (6:2:2, v/v/v), acidified with 1% (v/v) formic acid. The samples were then sonicated for 10 min in an ice bath and subsequently centrifuged at 4 °C for 5 min. Three extraction cycles were performed, and the resulting supernatants were pooled, concentrated by rotary evaporation, and redissolved in deionized water. For analysis, the extracts were diluted to 0.3125% (v/v). Total phenolic content was determined using the Folin–Ciocalteu method, while flavonoids were assessed using the aluminum chloride (AlCl₃) complexation method. Antioxidant capacity was evaluated using the ABTS, DPPH, and ORAC assays. The total phenolic content was 32.15 mg/g of dry sample. Antioxidant capacity reached 118.18 µg TE/mg of dry sample in the ABTS assay and 206.25 µg TE/mg in the DPPH assay. The ORAC assay, which evaluates the capacity to protect against oxidation induced by peroxyl radicals, yielded a value of 1,001.09 µmol TE/g of dry sample. Flavonoids were not detected under the analytical conditions employed; however, their presence at concentrations below the method's detection limit cannot be ruled out. Overall, the results demonstrate measurable antioxidant activity across all three assays, suggesting the presence of compounds capable of acting in different oxidative systems. This characterization highlights bacaba pulp as a promising raw material of interest to food science. Future studies should identify the compounds associated with the observed antioxidant responses, evaluate their stability during processing, and determine their bioaccessibility following gastrointestinal digestion. Such investigations may provide a scientific basis for the technological exploitation of bacaba in the development of higher-value food ingredients and products, while promoting the valorization of the regional bioeconomy. 

Acknowledgments: CNPq (Grant No. 402362/2025-0), CAPES - Finance Code 001