Effects of blanching on antioxidant property of Malabar Spinach (Basella rubra) ethanolic extract

摘要

Malabar spinach (B. rubra Linn), a local vegetable among the Yoruba people in Nigeria has been reported to exhibit an immense potential in androgenic activity, antiulcer activity, antioxidant activity, antibacterial activity and anti-inflammatory activity. Blanching is a common cooking method used to prepare soup with this vegetable among the local people. This research work investigated the effects of blanching on the antioxidant property of the ethanolic extract of B. rubra. By assaying for 2, 2-diphenyl-1-pierylhydrazyl (DPPH) scavenging activity, metal chelating ability, reductive property, nitric oxide scavenging activities and lipid peroxidation inhibitory activities. In addition, total phenolic content, total flavonoid content and total antioxidant activity of the blanched and un-blanched B. rubra samples were determined. Blanching decreased the antioxidant activity of the vegetable at different concentrations except for the reductive property that slightly increased after blanching. At 80 mu g/ml, blanching Malabar leaves ethanolic extract scavenged DPPH at 22.88% while the un-blanched sample scavenged DPPH at 26.80%. In the metal chelating assay, the un-blanched Malabar spinach showed 93.79% of Fe2+ chelation at 100 mu g/ml while blanched Malabar spinach was 89.83%. The phenolic content of the plant is much more than its flavonoid. The phenolic content of the blanched and un-blanched Malabar spinach was 121.83 and 341.00 mu g GAE/mg respectively; while the flavonoid content of the blanched and un-blanched Malabar spinach was 62.77 and 65.63 mu g QE/mg respectively.