Nutritional and Bioactive Characterization of <i>Amaranthaceae</i> Seeds From Peru, Slovakia, and Poland: A Comparative Study

<i>Amaranthus</i> sp. represents a promising pseudocereal due to its resilience to adverse environmental conditions and extensive nutritional benefits. This study evaluated amaranth samples from Peru, Slovakia, and Poland to compare their proximate composition, mineral content, amino acid profiles, antioxidant potential, and specific lipid fractions (phytosterols, squalene, and tocopherols). Results revealed significant regional variability: Polish cultivars generally exhibited the highest (<i>p</i> < 0.05) protein and squalene concentrations, while certain Peruvian kiwicha varieties excelled (<i>p</i> < 0.05) in total phenolic compounds and antioxidant capacity. Mineral analyses confirmed diverse calcium, magnesium, and iron levels, underscoring environmental and genetic influences. Amino acid profiling highlighted consistently high (<i>p</i> < 0.05) lysine and leucine, particularly in high-protein samples, reinforcing amaranth's potential as a complementary protein source. Lipid analysis revealed substantial (<i>p</i> < 0.05) phytosterols (dominated by <i>β</i>-sitosterol) and varying tocopherol isomers, with certain cultivars displaying notably high <i>δ</i>-tocopherol. Correlation and principal component analyses further demonstrated trait clustering (e.g., protein, squalene, and essential amino acids), suggesting targeted breeding opportunities to optimize nutritional density and bioactive composition. These findings reaffirm amaranth's application in functional food development, particularly in gluten-free applications, and emphasize its role as a strategic crop in addressing nutritional deficiencies and promoting dietary diversity.