Morphological and chemical diversity in amaranth

Amaranth is a neglected crop but it has great potentials because of its rich nutrients and phytochemicals that are linked to good health. It is easy to grow and is adapted to a wide range of environment including idle and problematic lands. Morphological characterization of 18 accessions of amaranth germplasm collection at National Plant Genetic Resources Laboratory (NPGRL) was done using standard descriptor published by Biodiversity international. A total of 34 characters comprising of 22 qualitative and 12 quantitative data were observed. Based on Shannon-Weaver Diversity Index, 17 characters (50%) were found to have high diversity (0.67) while two characters were invariant. Using Gowers coefficient at 0.7 r2, 5 clusters were generated from all the morphological characters. Evaluation of antioxidant activity, total phenol content, flavonoids and tannins revealed variations in the amaranth collections. GB56174, LSG09-002 and PHL6220G showed good potentials on the parameters measured. Different experiments to evaluate the antioxidant properties of amaranth, on different plant parts, growth stages, sampling time, variety, storage condition and length, and cooking time were also conducted. The level of anti-oxidants in the different parts of amaranth followed the sequence: leaves greater than or equal to flowers stem = roots. No significant difference was observed on the different stage of the plants (3 weeks vs. Flowering). The effect of differences in the antioxidant properties of amaranth at different sampling time is accession specific. Amaranth leaves can only be stored for 3 days at ambient condition while sample can be kept in the refrigerator for 7 days without a significant reduction in the antioxidant activity of the vegetable. Cooking the leaves for 3 to 7 min significantly reduced its antioxidant activities compared to fresh and blanched leaves. The cooking water of the cooked leaves however had higher antioxidant activities than those of the blanched leaves.