Abstract
<title>Abstract</title> <p> The accumulation of primary metabolites and phytochemicals in <italic>Nymphaea</italic> flowers suggests considerable metabolic diversity within this genus. Nevertheless, while current horticultural selection primarily emphasizes ornamental aesthetics, systematic evaluations of the phytochemical composition across germplasm collections remain scarce. In this study, 20 parameters encompassing nutritional composition, secondary metabolite content, and <italic>in vitro</italic> antioxidant capacity were assessed across 13 tropical <italic>Nymphaea</italic> accessions. Significant inter-accession variability was observed for all the measured traits. Subsequent correlation and regression analyses identified crude protein, total free amino acids, total phenolics, and total flavonoids as the primary determinants significantly associated with antioxidant capacity. Furthermore, a comprehensive assessment using the entropy-weighted TOPSIS model revealed that nutritional metrics contributed more substantially to the overall variance than did antioxidant indices. Among the accessions, NY5 consistently exhibited the most favorable integrated profile. Collectively, these findings offer foundational insights into the phytochemical landscape of tropical <italic>Nymphaea</italic> , facilitating future germplasm characterization. </p>