Annona muricata L. (Annonaceae) is a tropical fruit tree in Sri Lanka and commercial utilization of this species is poor. The objective of the present study was to determine the antioxidant activity and the total phenol content of the ethanolic extract of fruit pulp of the Sri Lankan variety of A. muricata. Antioxidant activity was determined by using 2,2-diphenylpicrylhydrazyl free radical scavenging assay, ferrous ion chelating assay, and ferric reducing ability of plasma assay. The total phenol content was determined by Folin-Ciocalteu method using Gallic acid standard. The fruit pulp extract exhibited scavenging activity having an IC50 value of 725 ppm and EC50 value for ion chelating activity as 306 ppm. The ferric reducing ability of 1000 ppm of the fruit pulp extract was equivalent to that of 25 ppm of vitamin C. The total phenol content of the extract of fruit pulp was 139 mg Gallic Acid Equivelant /100 g. The ethanolic extract of Sri Lankan variety of A. muricata fruit pulp exhibited moderate antioxidant capacity in terms of redox properties.
Tropical Agricultural Research Vol. 25 (2): 252 – 260 (2014)