CONTRIBUTIONS TO THE BOTANY AND NUTRITIONAL-VALUE OF SOME WILD AMARANTHUS SPECIES (AMARANTHACEAE) OF NUEVO-LEON, MEXICO

Seeds and plants of Amaranthus have been a source of food for many cul tures in the world. Some species can be found as weeds or growing wild under severe climatic and soil conditions, but their potential as foo d sources has not been studied The objective of this work was to study the nutritional quality of four wild species of Amaranthus, A. retrof lexus (AR), A. viridis (AV), A. palmeri (AP) and A. blitoides (AB) as potential sources of vegetable greens. Histochemical studies showed hi gher levels of starch in leaves of AR and AB, moderate amounts of tann ins in all leaves, high protein concentration in stems and leaves, and moderate amounts of alkaloids in all tissues of AV and AB. Antinutrit ional factors (nitrates, oxalates, cyanogenic glycosides, tannins and phytates) were quantified in plants at the preflowering stage, but onl y nitrates were found at levels (0.34-2% dw) above those generally con sidered as safe, but at similar levels found in spinach. No cyanogenic glycosides were detected in any species. Bromatologic analysis of who le or different plant parts at preflowering and maturity (mature seeds ) showed that mature whole plants or individual sections can be recomm ended as animal feed since they contain high levels of protein (20.6-2 4.7% whole plant, 25.3-32.9% leaves) and soluble carbohydrate (>40%). Amaranthus plants could be best consumed as vegetables at the preflowe ring stage. At this stage, the highest protein concentrations were fou nd in leaves (22.8-27.8%), while the remaining chemical composition wa s very similar to that found in other food vegetables. The four specie s showed similar chemical compositions, and had no detrimental chemica ls which would deter their use as vegetable foods. Organoleptic taste preference studies would best indicate the stage at which the plant sh ould be harvested for human consumption