Nutritional, pharmacological and antioxidant properties of water chestnut (Trapa spp.) as affected by genotypes

Background and Objective: For potential detoxifying capacity of Trapa spp., increasing attention has been paid to the nutritional and pharmacological values for clinical purposes.  Materials and Methods: Nutritive components and minerals of fresh water chestnut kernel were estimated by standard methods whereas the total phenolic and flavonoids by spectro-photometrically. The antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method and the ferric reducing antioxidant power (FRAP) assay.  Results: In fresh seed kernel ofeight genotypes protein, carbohydrates, fat, fiber and minerals content varied from 2.79±0.13-3.90±0.19%, 22.79±0.94%-25.63±0.77 %, 0.38±0.02-0.50±0.04%, 1.76±0.05-2.02±0.09 %and 1.42±0.25-2.08±0.06%, respectively. The total phenolic and flavonoid contents ranged from 340.81±10.16 to 651.56±18.44 mg GAE/100 g FW and 76.64±1.43 to 147.68±2.85 mg QE/100 g FW respectively. The commercial cultivars, Bihar Large Red had the highest DPPH and FRAP values 389.34±6.92 mg AEAC/100 g FW and 248.22±8.2 mg AEAC/100g FW, respectively. However, the DPPH activities of Green Spineless (387.70±11.93 mg AEAC/100 g FW) was at par with Bihar Large Red and FRAP values of former was 211.80±6.5 mg AEAC/100g FW and acquired 2nd rank. Higher phenolic content was associated with higher DPPH scavenging activity in fresh water chestnut kernel. Furthermore, high K/Na ratio and total of cations (Ca2++Mg2+) content of fresh kernel were promising for controlling B.P. and obesity.  Conclusions: For having more plentiful nutritional, phyto-chemicals and antioxidant components water chestnut may be considered as nutrient dense high value medicinal super food.