Antioxidant properties of selected fruit cultivars grown in Sri Lanka

Abstract

Extracts of twenty locally available Sri Lankan fruits were analysed for 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferrous reducing antioxidant power (FRAP), total phenolic content (TPC), total flavonoid content (TFC) and vitamin C content. The results showed that gooseberry (Phyllanthus emblica 'local') exhibited the highest DPPH scavenging activity (111.25mg ascorbic acid equivalent antioxidant capacity (AEAC)/g), FRAP (1022.05μmol FeSO₄/g), TPC (915.7mg gallic acid equivalents (GAE)/100g), TFC (873.2mg catechin equivalents (CE)/100g) and vitamin C (136.8mg ascorbic acid equivalents (AAE)/100g), respectively. Sugar apple (Annona squamosa 'local') and star fruit (Averrhoa carambola 'Honey Sweet') obtained the second and third highest antioxidant activities in terms of rankings of FRAP, DPPH activities, TPC, TFC and vitamin C content. Strong correlation between vitamin C, TPC and TFC with FRAP and DPPH showed their contribution to antioxidant capacity. Among the selected fruits, underutilized fruit cultivar gooseberry showed the highest overall antioxidant potential.

Keywords: 2,2-Diphenyl-1-picrylhydrazil (DPPH) (PubChem CID: 74358); 2,4,6-Tris(2-pyridyl)-s-triazine (TPTZ) (PubChem CID: 77258); 2,6-Dichloroindophenol (PubChem CID: 13726); Aluminum trichloride (PubChem CID: 24012); Antioxidants; Ascorbic acid (PubChem CID: 54670067); Catechin (PubChem CID: 9064); DPPH; FRAP; Folin-Ciocalteu’s reagent (PubChem CID: 516996); Gallic acid (PubChem CID: 370); Metaphosphoric acid (PubChem CID: 3084658); Methanol (PubChem CID: 887); Sri Lanka; Total flavonoid content; Total phenolic content; Underutilized fruits; Vitamin C.