VALORIZATION OF ARAÇÁ-BOI SEED (Eugenia stipitata): PHYSICOCHEMICAL CHARACTERIZATION, CENTESIMAL COMPOSITION, AND ASSESSMENT OF BIOACTIVE POTENTIAL SUPPORTING ITS USE AS A VALUE-ADDED BY-PRODUCT

Araçá-boi (Eugenia stipitata McVaugh, Myrtaceae) is a fruit native to the Amazon and increasingly cultivated in other Brazilian regions; although its pulp has gained attention, the seed is routinely discarded as agro-industrial residue, with scarce data on its chemical and bioactive profile. Therefore, this study aimed to characterize the centesimal composition, physicochemical parameters, and antioxidant potential of fresh araçá-boi seeds, discussing their technological feasibility for drying and development into a functional flour. Seeds were obtained from ripe, frozen fruits supplied by family farming producers in Magé, Rio de Janeiro, and processed at the Integrated Center for Food and Nutrition of the Fluminense Federal University (CIAN/UFF), where centesimal composition and physicochemical parameters (pH, titratable acidity, water activity) were analyzed. For determination of total phenolic content (Folin-Ciocalteu) and antioxidant activity (DPPH, ABTS, FRAP), extracts were prepared from ground seeds by maceration in water or 70% ethanol, followed by 24 h under refrigeration (5°C), filtration, and storage at −20°C, protected from light until analysis. All assays were performed in triplicate and evaluated by ANOVA/Tukey's test (p<0.05). Seeds showed a carbohydrate-predominant composition (85.01 ± 1.12% on a dry weight basis), alongside protein (6.53 ± 0.05%), fiber (6.36 ± 0.88%), ash (1.12 ± 0.16%), and low lipid content (0.98 ± 0.28%), corresponding to an energy value of 374.96 ± 3.26 kcal/100 g. Physicochemical parameters revealed a moderately acidic pH (4.31 ± 0.05) and high water activity (0.94 ± 0.01), consistent with high moisture content (60.61 ± 1.01%). Among extraction conditions, 70% ethanol yielded the highest bioactive recovery (p<0.05), with total phenolic content of 19.13 ± 1.21 mg GAE/g and antioxidant activity of 1007.72 ± 18.21 µM TE/g (DPPH), 450.80 ± 21.17 µM TE/g (ABTS), and 334.83 ± 19.74 µM FSE/g (FRAP). The carbohydrate-rich, low-lipid composition, combined with relevant protein and fiber content, indicates a nutritionally favorable profile, suggesting suitability for low-fat functional formulations. This profile is consistent with seed flours from other Myrtaceae species, such as jambolan (Syzygium cumini) and jabuticaba (Myrciaria spp.), reinforcing the technological potential of these residues as carbohydrate-based raw materials. Given the seed's high moisture and water activity, drying emerges as a key processing step to obtain a stable flour-type material. The phenolic content and antioxidant activity of fresh seeds further suggest their potential as a bioactive-rich raw material, although their preservation after drying remains to be assessed. Overall, these findings support the seed's valorization as promising raw material for flour development, contributing to zero-waste strategies and the valorization of native Brazilian fruit by-products.