Investigation of Nutritional Properties of Standardized Wattakaka Volubilis Linn. F. Stapf: a Green Leafy Vegetable

Wattakaka volubilis Linn. F Stapf (Family: Asclapadaceae) is a leafy vegetable and a medicinal plant in Asian countries. In the present study, an attempt was made to (a) standardize and (b) investigate nutritional properties of W. volubilis grown in Sri Lanka. W. volubilis leaves were standardized by (a) determination of physicochemical parameters, (b) screening for phytochemicals and (c) development of TLC fingerprint. Nutritional properties were investigated in terms of protein, crude fat, carbohydrates, dietary fiber, magnesium, iron and calcium percentage. Antioxidant potential was investigated by (a) DPPH assay and (b) estimation of total polyphenolic and flavonoid contents. Results revealed that W. volubilis leaves consist of 16.5% of total ash, 0.8% of acid insoluble ash, 6.1% of water soluble ash, 32.6% of protein, 3.3% of crude fat, 17.8% of carbohydrates, 24.8% of dietary fiber, 0.5% of magnesium, 0.4% of iron and 1.0% of calcium. Antioxidant potential of W. volubilis leaves (IC50: 7.06 ± 0. 40 μg/mL) was comparable to that of L -ascorbic acid (IC50: 6.40 ±0.21 μg/mL) and found high amounts of falvonoids and phenols. In conclusion, nutritional properties of W. volubilis leaves was established for the first time and observed physicochemical and phytochemical parameters may be used as tools to standardize W. volubilis grown in Sri Lanka.