Evaluation Of Antioxidant Capacity, Phenol And Flavonoid Contents Of Opuntia Streptacantha And Opuntia ficus Indica Fruits Pulp

The aim of this study was to determine phenolic and flavonoid content and to evaluate antioxidant activity of fruit's pulp from 2 Opuntia species [Opuntia ficus-indica (OFI) and Opuntia streptacantha (OS)]. Samples were extracted with methanol and kept at 4°C until investigation. Total phenolics were determined by Folin-Ciocalteu method. Flavonoids were inspected based on the formation of flavonoid-aluminium complex. Antioxidant activity was evaluated using three different methods: the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, the reducing power and the β-carotene bleaching test (BCB). O. streptacantha fruit extract contain more phenolics and flavonoids than O. ficus-indica. Using the DPPH method, the reducing power and the BCB, the highest activities were found for the extraction of OS fruit with the lowest EC50 values (5.76 ± 0.46, 2.01 ± 0.03 and 2.93 ± 0.77 mg/ml, respectively). The amount of phenolic and flavonoid compounds was implied as possible factor witch influenced the antioxidant power of the OFI and OS fruit extract