Antioxidant activity of mangaba (Hancornia speciosa) and acerola (Malpighia emarginata) fruit pulp and residues

Abstract

Antioxidants are compounds which protect the biological system against the damaging effects of processes or reactions that can cause excessive oxidation. Fruits contain various antioxidants whose activities have been well proven in reduction of degenerative diseases. The aim of the study was to determine the total antioxidant activity by free radical capture method DPPH (2,2-diphenyl-1-picryl hydrazyl), TEAC (Trolox Equivalent Antioxidant Capacity) and ORAC (Oxygen Radical Absorbance Capacity) and compare the levels of total phenolic compounds in ethanol, methanolic and aqueous extracts of pulp and residue of mangaba and acerola fruits. The flour was obtained by the residue of the peel and seeds of the fruits after pulping, the extracts were obtained by ethanol, methanol and water using ultrasound. The DPPH and TEAC tests were performed with a spectrophotometer at 517 and 750 nm, respectively, while ORAC was carried out with the aid of fluorimeter, using 520 nm emission and 485 nm excitation filters. The results showed better antioxidant activity with the aqueous extracts in all methods, but the TEAC method had the highest antioxidant activity for acerola pulp and residue (429 µM Trolox g-1 and 90.89 µM Trolox g-1, respectively), followed by mangaba pulp and residue (201 µM Trolox g-1 and 61.87 µM Trolox g-1, respectively). In addition, the highest content of phenolic compounds was found in the residue of acerola (31 mg gallic acid 100 g-1), followed by the mangaba pulp (21 mg gallic acid 100 g-1).