PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY OF AN ETHANOLIC EXTRACT FROM CUPUAÇU(Theobroma grandiflorum) SEED CAKE

Cupuaçu (Theobroma grandiflorum) processing generates residues that can be used as sources of bioactive compounds. Among these residues, seed cake is obtained after oil extraction and can still contain compounds with antioxidant activity. This study aimed to evaluate the extraction yield, phenolic and flavonoid contents, and antioxidant activity of an ethanolic extract obtained from industrial cupuaçu seed cake. The project was registered in the Brazilian National System for the Management of Genetic Heritage and Associated Traditional Knowledge (SisGen) under registration code AB17D6E. The seed cake, produced by hydraulic pressing, was supplied by Amazon Oil, Ananindeua, Pará, Brazil. The material was dried in a forced-air oven at 45 °C for 72 h, ground, and sieved through a 24-mesh sieve. For extraction, 40 g of the dried material were subjected to Soxhlet extraction for 8 h using 92.8° INPM ethanol previously distilled with 2 g/L NaOH. The extraction yield was determined, total phenolic content was measured by the Folin–Ciocalteu method, and total flavonoid content by the aluminum chloride method. Antioxidant activity was evaluated by DPPH and FRAP assays. The extraction yield was 22.93%. Total phenolic and flavonoid contents were 62.45 ± 1.40 µg GAE/mg extract and 45.79 ± 1.62 µg QE/mg extract, respectively. In the DPPH assay, the extract showed 82.71 ± 1.53 µg TE/mg extract and 52.98 ± 0.86% inhibition at 1 mg/mL. In the FRAP assay, the antioxidant activity was 66.86 ± 6.04 µmol FeSO₄/mg extract. These results show that cupuaçu seed cake contains phenolic and flavonoid compounds and presents antioxidant activity even after the seed oil extraction process. Thus, this industrial residue can be considered a potential source of bioactive compounds and an alternative for the use of residues generated during cupuaçu processing. This study was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); and Fundação Amazônia de Amparo a Estudos e Pesquisas (FAPESPA).