Salinity stress accelerates nutrients, dietary fiber, minerals, phytochemicals and antioxidant activity in Amaranthus tricolor leaves.

Impact of salinity stress were investigated in three selected Amaranthus tricolor accessions in terms of nutrients, dietary fiber, minerals, antioxidant phytochemicals and total antioxidant activity in leaves. Salinity stress enhanced biochemical contents and antioxidant activity in A. tricolor leaves. Protein, ash, energy, dietary fiber, minerals (Ca, Mg, Fe, Mn, Cu, Zn, and Na), β-carotene, ascorbic acid, total polyphenol content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC) (DPPH and ABTS+) in leaves were increased by 18%, 6%, 5%, 16%, 9%, 16%, 11%, 17%, 38%, 20%, 64%, 31%, 22%, 16%, 16%, 25% and 17%, respectively at 50 mM NaCl concentration and 31%, 12%, 6%, 30%, 57%, 35%, 95%, 96%, 82%, 87%, 27%, 63%, 82%, 39%, 30%, 58% and 47%, respectively at 100 mM NaCl concentration compared to control condition. Contents of vitamins, polyphenols and flavonoids showed a good antioxidant activity due to positive and significant interrelationships with total antioxidant capacity. It revealed that A. tricolor can tolerate a certain level of salinity stress without compromising the nutritional quality of the final product. This report for the first time demonstrated that salinity stress at certain level remarkably enhances nutritional quality of the leafy vegetable A. tricolor. Taken together, our results suggest that A. tricolor could be a promising alternative crop for farmers in salinity prone areas- in the tropical and sub-tropical regions with enriched nutritional contents and antioxidant activity.