Nutraceutical Prospects and Antioxidant Activity of White and Red Water Lily Stem Available in Bangladesh

Abstract

Generally, the white and red water lily cultivars' stems are consumed as vegetables in Bangladesh. However, data on the nutritional benefits and antioxidant properties of these aquatic plant’s stem are scant. Considering the aforementioned possibilities, the goal of this study was to evaluate the nutritional value, anti-nutritional factors, and antioxidant activity of two common Nymphaea species such as Nymphaea nouchali (white variety), and Nymphaea rubra (red variety) grown in Bangladesh. The proximate analysis and mineral content were determined by following AOAC methods. Crude fiber content was significantly higher in the white lily (19.56±0.68%) compared to the red cultivar (16.24±1.05%). Conversely, the red lily showed a higher value (18.52±1.01%) for ash content than the white species (15.44±0.79%). However, the varieties had no significant differences in moisture, protein, fat, and carbohydrate content. Both stems were rich in essential minerals, whereas Na and Cu were significantly higher in white water lily (WWL); however, the red water lily (RWL) stem possessed significantly copious amounts of K and P. On the other hand, there was no significant difference between two species in the case of Ca, Mg, Fe, and Zn content. The assay showed that the total phenolic contents (mg GAE/g) and total flavonoid contents (mg QE/g) were 16.51±0.05 and 15.48±02, 476±0.1 and 7.846±0.1 in white and red water lily stems respectively. In addition, the anti-nutrient screening revealed that both species were positive for saponin and tannin. Furthermore, the extract of RWL stem showed more antioxidant activity (IC50 value 28.48±0.12µg/ml) against DPPH than WWL (IC50 value 36.67±0.09 µg/ml). Thus, water lily stems can be incorporated into our diet as a potential natural source of antioxidants and vital elements.