Amaranths: The Crop of Great Prospect

Abstract

Amaranthus L. is an herbaceous genus of the family Amaranthaceae, collectively known as amaranths or pigweed. The species of Amaranthus are mostly annual weeds; few are utilized as vegetables and ornamentals. Protein rich grains or seeds of few species (, A. caudatus L., Amaranthus hypochondriacus L. and A. cruentus L.) are consumed as pseudo-cereals, they are called grain amaranths. Although grain amaranths (A. hypochondriacus, A. cruentus and A. caudatus) are the crop of Americas but Amaranthus hypochondriacus migrated to Asia during the last century. Few authors opined that grain amaranths have been cultivated in South Asia from time immemorial and probably originated there. Its maximum cultivation and distribution at present is observed in the Himalayas. Cultivation of grain amaranths in India is very ancient. The study further suggests that either of the grain amaranths i.e. A. hypochondriacus and A. caudatus have independently originated or were introduced in the Old World before 1500 AD. Amaranthus hypochondriacus was probably domesticated in Central Mexico and further north much after the domestication of Amaranthus cruentus which was domesticated in Central America (Mexico and Guatemala.). Amaranthus caudatus originated in the Andean high lands of Argentina, Peru, and Bolivia where common potato originated. The `protein component of grain amaranth, its quantity and quality with extremely balanced amino acid composition is very close to the levels recommended by FAO/WHO is due to the fact that in amaranth 65{\thinspace}% of the proteins are found in the embryo and only 35{\thinspace}% in the perisperm. Grain amaranths are the rich source of Squalene, Tocotrienol (known to lower the LDL cholesterol), anti nutritive components like -- Saponins, Tannin and trypsin inhibitor. Vegetable amaranths (like A. tricolor L., A. blitum L., A. dubius, A. cruentus) are grown in the hot, humid regions of South East Asia (especially Malaysia and Indonesia), Africa, Southern China, India and Caribbean islands. They are very rich in protein, calcium, iron, vitamin A, C and K, riboflavin, (B2), niacin (B3), vitamin B6 and folate which have attributed to their high nutritive value. The underutilized amaranths are good options and projected as a future crop of twenty-first century. Methods of preparation or cooking practices are very vital to maintain proper nutritive value and the level of bioactive components. Vegetable amaranths are ranked as one of the top five vegetables in antioxidant capacities having a plenty of bioactive components. Future promise of vegetable amaranths is the preparation of leaf protein concentrate. Beside crops and ornamentals, genus includes many weedy species known as pigweeds. Noxious nature of these weedy species lies in their ability to withstand any agricultural modification practices.