Abstract

• The objectives of this research work were to evaluate the nutritional values, phytochemicals, total phenolic, total flavonoid and antioxidant activity of red and white flower petals of Sesbania grandiflora (L.) Pers. Red and white flower petals possess nutritional values of moisture (6.13 and 5.28 %), ash (4.37 and 5.10 %), fiber (1.40 and 3.60 %), protein (5.99 and 8.32 %), fat (0.83 and 1.53 %), carbohydrates (81.28 and 76.17 %) and energy value (357 and 352 kcal/100 g), respectively. Both varieties of flower samples contain plenty of phytochemicals such as alkaloids, phenolic compounds, flavonoids, steroids, terpenoids, glycosides, α-amino acids, starch, reducing sugars, carbohydrates, saponin and tannins. The total phenolic content was determined by FolinCiocalteu assay and expressed as gallic acid equivalent. Total phenolic content of red flower petals was found to contain 185.15 μg GAE/mg of ethanol extract and 82.08 μg GAE/mg of aqueous extract. Total phenolic content of white flower petal was found to contain 134.38 μg GAE/mg of ethanol extract and 55.92 μg GAE/mg of aqueous extract. Total flavonoid content was determined by aluminium chloride colourimetric method and expressed as quercetin equivalent. It was observed that red flowers contain total flavonoid content of 356.85 μg QE/mg of ethanol extract and 285.33 μg QE/mg of aqueous extract, and white flowers contain 45.33 μg QE/mg of ethanol extract and 22.30 μg QE/mg of aqueous extract. Antioxidant activity of each extract was evaluated by DPPH assay. In DPPH assay, IC50 values were used to determine the antioxidant potential of the sample. Among the extracts ethanolic extracts of both red and white flower varieties exhibited higher DPPH radical scavenging activity with IC50 value of 213.67 μg/mL and 322.31 μg/mL, respectively. S. grandiflora can be regarded as promising candidates for natural plant sources of antioxidant with high values.