Nutrients, minerals, antioxidant pigments and phytochemicals, and antioxidant capacity of the leaves of stem amaranth

Umakanta Sarker,Shinya Oba,Moses Ahmed Daramy

doi:10.1038/s41598-020-60252-7

Abstract

We evaluated 17 genotypes of stem amaranth (Amaranthus lividus) in terms of dietary fiber, moisture, carbohydrates, fat, ash, gross energy, protein, minerals, phytopigments, total antioxidant capacity (TAC), vitamins, total flavonoids (TFC), total polyphenols (TPC) and their variations. Stem amaranth leaves have abundant dietary fiber, moisture, carbohydrates, and protein. We found significant amount of potassium, calcium, magnesium (9.61, 24.40, and 29.77 mg g−1 DW), iron, manganese, copper, zinc, (1131.98, 269.89, 25.03, and 1006.53 µg g−1 DW), phytopigments such as chlorophyll a, chlorophyll ab chlorophyll b, (27.76, 42.06, and 14.30 mg 100 g−1 FW), betalain, betaxanthin, betacyanin (62.92, 31.81, 31.12 µg 100 g−1 FW), total carotenoids, beta-carotene (1675.38, 1289.26 µg g−1 FW), vitamin C (1355.46 µg g−1 FW), TPC, TFC (228.63 GAE and 157.42 RE µg g−1 DW), and TAC (DPPH, ABTS+) (26.61, 51.73 TEAC µg g−1 DW) in the leaves of stem amaranth. Genotypes exhibited a wide range of variations. Three genotypes DS40, DS30, and DS26 could be used as an antioxidant profile enriched stem amaranth. Phenolics, phytopigments, flavonoids, and vitamins of stem amaranth leaves exhibited strong antioxidant activity. Stem amaranth could be a potential source of dietary fiber, moisture, carbohydrates, protein, minerals, phenolics, phytopigments, flavonoids, and vitamins in our daily diet for attaining nutritional and antioxidant sufficiency.

Highlights

Amaranth has great variability and phenotypic plasticity[1] with many culinary uses
Staple foods are deficient of micronutrients, mainly iron, zinc and iodine, pro-vitamin A, carotenoids, vitamin C, E, albeit these are a source of energy[13]
We found a significant amount of K (9.61 mg g−1), calcium (24.40 mg g−1) and magnesium (29.77 mg g−1) in the leaf of stem amaranth, albeit we determined based on the dry weight

Summary

Introduction

Amaranth has great variability and phenotypic plasticity[1] with many culinary uses. In Bangladesh including south-east Asia, Africa, South America, the edible stem amaranth leaves are a very famous vegetable. Leaf pigments (betacyanin, betaxanthin, chlorophyll, and carotenoids), vitamin C, phenolics and flavonoids are available natural antioxidants in amaranths[4,17]. To fill these gaps, the present investigation was undertaken to evaluate proximate and mineral compositions, leaf pigments, vitamins, phenolics, and flavonoids content in 17 stem amaranth genotypes.

Results

Conclusion