Polyphenols in Caja-Umbuzeiro Fruit: Extraction Process Efficiency and Antioxidant Potential

To define the procedure for efficient extraction of polyphenols and to evaluate the antioxidant potential of cajaumbu fruit, four genotypes (G 2.2, G 2.3, G 3.1 and G 3.2) were used to obtain hydroacetonic, hydromethanolic and aqueous extracts. Three extraction systems were utilized and the extracts obtained were screened for their free DPPH• (1,1-diphenyl-2-picrylhydrazyl) and ABTS•+ (2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) scavenging activity and their effect on the linoleic acid peroxidation by the ferric thiocyanate method and β-carotene-linoleic acid cooxidation system. The highest total phenolic content was achieved with the system in which 80% acetone was the first organic solvent applied (1528 to 2644 μg GAE/mL). All genotypes exhibited good DPPH• scavenging capacity (>70%), except for the G 3.1 genotype, EC50 value of 0.30 to 0.43, TEC50 value of 8.98 to 15.24 minutes, and EA value of 0.18 to 0.40; significant ABTS•+ scavenging capacity (55.56 a 120.08 μMol TEAC/g) and high percentage of inhibition of peroxidation of linoleic acid (88.45 to 92.89+). In co-oxidation of the linoleic acid/β-carotene system, all genotypes exhibited moderate activity (56.91 to 69.41%), showing that they are effective in blocking the onset of oxidation reaction (F1<1). Therefore, caja-umbu fruit has a good antioxidant potential and may contribute to the dietary intake of antioxidants.