Nutritional potential, phytochemical analysis, and biological activities of quinoa (Chenopodium quinoa Willd.) seeds from arid zone culture

Quinoa, scientifically known as Chenopodium quinoa Willd., is well recognized for its exceptional nutritional composition and potential benefits for human health. This research aims to conduct a phytochemical analysis of nutraceutical properties and biologcal activities of seven different quinoa cultivars, namely, red, white, Amarilla marangani, kancolla, Giza 02, Amarilla sacaca, and black. The analysis of ground seeds revealed that Giza 02, white, and A. marangani had the most significant protein, fat, ash, and carbohydrates, respectively. Furthermore, the MeOH extracts of the various quinoa genotypes exhibited high levels of total phenolic, flavonoid, condensed tannin and reducing sugar contents in the seed extracts obtained using consecutive solvents. In addition, HPLC-DAD analysis revealed the presence of seven phenolic compounds, which may be classified into four families: phenolic acid, flavonoids, coumarins, and stilbenes. The IC50 values for the antioxidant activity ranged from 6.4 to 7.7 µg/mL. Furthermore, the variability in the antibacterial activity across different genotypes and gram-positive and gram-negative bacterial species was observed, and the efficacy of the CYHA-red extract against Micrococcus luteus was the highest. The findings of this study indicate that the incorporation of quinoa into the arid and Saharan cultivation system has the potential to enhance the nutritional and nutraceutical characteristics of the seeds.