Characterization of grains and physiological quality of seeds of Amaranthus spp

Abstract

The aim of this thesis was to characterize grains and verify the seed quality of three Amaranthus species. In the first article, the harvested grains were transformed into flour and the centesimal composition was determined, as well as macro and micronutrients, content of starch and nitrate. It can be inferred that in the majority of the analyzes for centesimal composition, the species A. hybridus and A. viridis presented higher levels than the commercial species. A. hybridus has the highest N, Mg, B, Mn and Fe content, the commercial species of P, K, S, Cu and Zn, while A. viridis of Ca and Cu. The starch content in the grains ranged from 32.86 to 36.21%. The nitrate content does not pose a health risk if consumed moderately. The species A. hybridus and A. viridis present great potential for grain production, whose nutritional properties of the flour in the majority of the analyzes performed were superior to commercial species. In the second article, characteristics of seed geometry and color were quantified. The seeds were analyzed with X-rays to evaluate their physical quality. A germination test was performed. Samples of these seeds were evaluated by near infrared spectroscopy (NIR). The commercial species presented in general terms the best results regarding the physiological quality of seeds. The use of the 0.2% KNO3 solution assisted the vigor of A. viridis and A. hybridus species. Through the NIR, it was possible to distinguish the three species used in the work according to their predominance of chemical components. In view of the above, it is concluded that the A. viridis and A. hybridus species have the potential to produce grain of nutritional quality, despite the lower seed characteristics in relation to the commercial species.