Elemental Composition of Xanthosoma sagittifolium in the Amazon: Nutritional Value and Potential as an Environmental Bioindicator in the Context of Amazonian Edaphic Variability

Xanthosoma sagittifolium (taioba) is an unconventional food plant of nutritional and socioenvironmental relevance.This study evaluated its elemental composition in five municipalities of Amazonas (Manaus, Itacoatiara, Novo Airão, Humaitá, and Tabatinga) to analyze its nutritional potential and use as an environmental bioindicator in the context of Amazonian edaphic variability.Rhizospheric soil and leaf samples were analyzed by total reflection X-ray fluorescence (TXRF).The results showed geochemical heterogeneity between the localities: soils of Tabatinga and Humaitá presented high concentrations of aluminum and iron, while the leaves revealed higher levels of phosphorus, potassium, calcium, and sulfur, especially in floodplain environments and seasonally flooded soils.The analysis of main components (PCA) showed clear separation between municipalities, confirming the edaphic influence on the mineral composition of the species.Positive correlations between nutrients (P, S, Si, K) and trace elements (Cr, Yb) indicated physiological adaptive mechanisms of absorption.The findings reinforce the dual role of taioba as both a food resource with high nutritional value and as a bio-indicator sensitive to environmental quality.However, the presence of traces of potentially toxic Pol.J. Environ.Stud.Vol.XX, No. X (XXXX), 1-11 elements highlights the need for continuous monitoring to ensure the safety of human consumption and to broaden understanding of taioba in Amazonian ecosystems.