Phytosterol and Polyphenol Contents and Quinoa Leave Yields Variation in Relationships to Variety, Density and Harvesting Date

• Published in: Agronomy (Basel) 2022-10, Vol.12 (10), p.2397
• Main Authors: Stoleru, Vasile, Vitanescu, Maricel, Teliban, Gabriel-Ciprian, Cojocaru, Alexandru, Vlase, Laurian, Gheldiu, Ana-Maria, Mangalagiu, Ionel, Amăriucăi-Mantu, Dorina, Burducea, Marian, Zheljazkov, Valtcho, Rusu, Oana-Raluca
• Format: Article
• Language: English
• Subjects: Agricultural production; Amino acids; bioactive compounds; Cancer; Cardiovascular disease; Chenopodium quinoa; Crop diseases; Cultivars; cultivation technology; Design factors; Ergosterol; Ferulic acid; Functional foods & nutraceuticals; Gluten; Grain; Harvesting; Leaves; Liquid chromatography; Morphology; Phenolic compounds; Phenols; Phytosterols; Planting; Planting density; Polyphenols; Quinoa; Seeds; Ultrasonic imaging; young leaves
• ISSN: 2073-4395; 2073-4395
• DOI: 10.3390/agronomy12102397

Quinoa is an Andean grain known for its gluten-free grains, which are used as a functional food. The aim of this research was to study the possibility of introducing quinoa as a vegetable crop grown for young leaves as a source of polyphenols and phytosterols. To achieve this goal, a field experiment was performed with three quinoa cultivars (Titicaca, Puno, and Vikinga) grown in a split plot design. The experimental factors included three densities (160, 320, and 760 plants·m−2) and two harvest dates (52 and 62 days after sowing (DAS)). The content of phytosterols (ergosterol, stigmasterol, β-sitosterol and campesterol) and polyphenols (ferulic acid, isoquercitrin and rutozid) in quinoa leaves were determined by HPLC method. The phytosterol content varied within the limits: ergosterol 0–7.62 µg·100 g−1 dw, stigmasterol 79.9–175.3 µg·100 g−1 dw, β-sitosterol 425.7–623.1 µg·100 g−1 dw and campesterol 0–5.25 µg·100 g−1 dw. Ferulic acid varied greatly from 38.0 to 63.3 µg·g−1 dw, isoquercitrin ranged from 63 to 101.6 µg·g−1 dw and rutozid varied widely from 32.9 to 162.8 µg·g−1 dw. The total phytosterols and the total phenolic compounds decreased with decreasing plant number density and DAS. This research demonstrated that young quinoa leaves are a good source of phytosterols and phenolics for human consumption.