Characterization of the centesimal composition, quantification of total carotenoids, and antioxidant capacity of tucumã-do-Amazonas (Astrocaryum aculeatum) peels

The tucumã-do-Amazonas (Astrocaryum aculeatum) is a native fruit that generates a significant amount of residue during processing. These resulting co-products have substantial potential for reuse, as they are rich in nutrients and bioactive compounds, such as phenolics, flavonoids, and carotenoids, which confer antioxidant and anti-inflammatory properties with health benefits. Therefore, to promote food reuse, this study aimed to characterize the centesimal composition of tucumã peels, quantify the total carotenoid content (TCC), determine the of total phenolic content (TPC), and evaluate their antioxidant capacity (AC). Analyses to determine the centesimal composition were performed using dried and crushed peels, with results expressed in grams (g) per 100 g of sample on a dry basis. Extracts were prepared using petroleum ether as a solvent for TCC analysis, followed by dilution and direct reading in a spectrophotometer at 450 nm. TPC was determined by the Folin-Ciocalteu method, while AC was evaluated by the ABTS and FRAP methods. For these last analyzes, a 40% (v/v) hydroethanolic extract was prepared, followed by dilution and spectrophotometric readings at 760, 734, and 595 nm, respectively. The results of the study indicated that tucumã peels have significant nutritional properties, characterized by 34.28% carbohydrates, 3.12% ashes, 26.24% fibers, 26.91% lipids, 8.22% proteins, and 1.23% moisture. TCC and TPC were found to be 33.10 µg β-carotene equivalent/g dry sample and 154.04 mg gallic acid equivalent/100 g dry sample, respectively. AC yielded values of 34.22 µmol Trolox equivalent/g dry sample (ABTS) and 156.49 µmol Trolox equivalent/g dry sample (FRAP). These findings highlight the potential for the utilization and valorization of tucumã peels, confirming the presence of bioactive compounds in the residue and suggesting a possible antioxidant application in functional foods as a sustainable alternative.