Interactive effects of cooking method, genotype and environment on nutritional and antinutritional quality of quinoa ( Chenopodium quinoa Willd .) seeds

BACKGROUND: Quinoa has gained global attention as a climate-resilient crop with high nutritional value and strong potential to enhance food security. Quinoa seeds are characterized by high-quality protein with a balanced essential amino acid profile and are rich in dietary fiber, vitamins, essential minerals, healthy lipids and bioactive compounds. This study aimed to evaluate the effects of boiling and steaming on the nutritional and antinutritional properties of five quinoa genotypes grown in two contrasting regions. RESULTS: Both environmental and genetic factors significantly affected key agronomic traits, with clear genotype × environment interactions. Overall, Q3 exhibited the best nutritional profile across both regions, combining high protein, starch, vitamin E, antioxidant capacity and the lowest levels of antinutritional compounds (saponins, tannins and phytic acid). By contrast, Q5 showed the least favorable profile, characterized by low yield, high saponin and tannin contents, and less consistent nutritional improvements after processing. Steaming consistently preserved or enhanced protein content, soluble sugars, polyphenols, flavonoids and DPPH (i.e. 2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity across all genotypes and sites, with the greatest protein increases observed in genotypes Q4 and Q5 from the northern site. By contrast, boiling significantly reduced protein, soluble sugar, starch, polyphenol and flavonoid contents in most genotypes. Both boiling and steaming significantly reduced phytic acid content at the same time as inducing genotype- and site-dependent changes in saponin and tannin levels. CONCLUSION: These results demonstrate the strong genotype-dependent effects of thermal processing and provide new insights into the interactions between genotype, environment and cooking method in shaping the nutritional composition of quinoa seeds.