Physicochemical and antioxidant evaluation of watercress (Rorippa nasturtium aquaticum L.) leaf extracts

This research aimed to evaluate the type of solvent (80% methanol, ethanol, and water), solute/solvent ratio (1 : 10 and 1 : 15 w/v), maceration time (0 h, 24 h and 7 d) and stage of leaf maturity [vegetative (VW) and generative (GW)] on the physicochemical and antioxidant properties of watercress leaf extracts. The leaf was characterised by determining the chemical composition, the phytochemical profile, and the colour. The GW presented the highest moisture content [93.25 g.(100 g)-1], carbohydrates [70.74 g.(100 g)-1], and lightness (L* = 59.66), and the presence of alkaloids, phytosterols, phenols, and flavonoids. VW had the highest protein content [26.52 g.(100 g)-1] and the lowest presence of phytochemicals. The best solvent for the extraction was distilled water at a 1 : 15 w/v ratio, GW at 24 h rest centrifuged at 2 300 × g for 15 min, obtaining the highest values of phenols [2 077 mg GAE.(100 g)-1], of dust and an inhibition power of 85.09% by the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS+) radical method. Therefore, cress leaves in the generative stage can be considered a potential source of bioactive compounds, and using water as an extracting agent for these compounds makes it a viable and economical method to be used in the food industry, and in addition, to be friendly to the environment.