Evaluation of Phenolic and Flavonoid Content, Antioxidant and Radical Scavenging Capacity of Baru (Dipteryx alata Vog.) Almond

Abstract

Abstract Objectives The legume plant species Dipteryx alata Vog., commonly known as baru, is a tree that grows in the Brazilian savanna. It produces drupe type of fruit and has an edible seed referred to as the baru nut. The baru nut is of interest as it possesses bioactive compounds useful in managing chronic diseases, yet little is known about its composition. Thus, the aim of this study was to determine the phenolic and flavonoid content, as well as antioxidant and radical scavenging capacity of the baru nut. Methods Baru nuts were roasted, pulverized, and freeze-dried prior to polyphenolic extractions, which were performed using 80% ethanol and ultrasonic bath. Baru crude extracts were then purified with chloroform, evaporated, and freeze-dried prior to being assayed. Total phenolic content and total flavonoid content of purified baru polyphenolic extracts were determined using Folin-Ciocalteu reagent and aluminum chloride colorimetric assay, respectively. Antioxidant capacity was measured using Trolox equivalent antioxidant capacity (TEAC) and ferric reducing antioxidant power (FRAP) while 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays were used to determine radical scavenging capacity. Results Total phenolic content of purified baru nut extract was 58 ± 10 μmol gallic acid equivalent/L while total flavonoid content was 7 ± 0 μg quercetin equivalent/mL. The TEAC of purified baru nut extract was 161 ± 5 μmol trolox equivalent (TE)/L, which was higher than its FRAP, 55 ± 0.5 μmol TE/L. Radical scavenging capacity of baru nut extract was 17 ± 3 and 5 ± 7 μmol TE/L according to DPPH and ORAC, respectively. Conclusions Baru nut is rich in polyphenols and has high antioxidant activity. Further research is warranted to determine the antioxidant properties of baru nut in vitro and in vivo. Funding Sources No sources of funding.