Phenolic Compounds and Antioxidant Properties of Puruí (Alibertia edulis, Rubiaceae), an Edible Dark Purple Fruit from the Brazilian Amazon

Albertia edulis is known as Puruí, and its leaf tea is used in the hypoglycemic and antihypertensive treatments of the Amazon native population. This study aimed to evaluate the phytochemical composition and antioxidant properties of the Puruí pulp fruit. The hydroethanolic (LFP-E), ethyl acetate (LFP-A), and volatile concentrate (LPF-V) extracts of Puruí lyophilized fruit pulp were analyzed via LC-ISI-IT-MS, GC, and GC-MS. Moreover, total phenolic and flavonoid content (TPC and TFC) and TEAC/ABTS and DPPH assays were conducted to determine their antioxidant capacity. Compounds palmitic acid, methyl linolenate, methyl linoleate, palmitic alcohol, benzene acetaldehyde, tridecanal, and furfural were mainly identified in the LPF-V extract. Compounds caffeic and quinic acids, genipin, annonaine, 3′-7-dimethoxy-3-hydroxyflavone, 4′-hydroxy-5,7-dimethoxyflavone, 6-hydroxy-7-epigardoside methyl ester, baicalin, and phloretin-2-O-apiofuranosyl-glucopyranoside were mainly identified in the LFP-E and LFP-A extracts. For LFP-E and LFP-A extracts, TPC values were 5.75 ± 0.75 and 66.75 ± 3.1 mg GAE/g; TFC values were 1.14 ± 0.65 and 50.97 ± 1.2 mg QE/g; DPPH assay showed EC50 values of 1021.65 ± 5.9 and 133.60 ± 3.9 µg/mL; and TEAC/ABTS assay showed values of 28.36 ± 3.7 and 142.26 ± 2.2 µM TE/g. Alibertia edulis fruits are significant sources of phenolic compounds, also showing significant antioxidant capacity. The Puruí fruit seems promising for developing innovative and healthy products for the nutritional food market.