Nutritional characterization of six quinoa (Chenopodium quinoa Willd) varieties cultivated in Southern Europe

•Proximate, amino and fatty acid, mineral and sugar composition in quinoa varieties.•Important role of quinoa grains in human diet.•Nutritional values according to composition traits reported for quinoa.•High protein content with a significant contribution of essential amino acids.•Low fructose, glucose and saponin content. Proximate, mineral and sugar composition, amino acid and fatty acid profile and saponin content were determined in six quinoa (Chenopodium quinoa Willd) varieties (Pasto, Atlas, Marisma, Jessie, Roja, Pot-4). The aim of this study was to provide a detailed characterization of the nutritional composition of these varieties cultivated in Southern Europe. In addition, saponin content was analyzed as an antinutritional compound. Results show nutritional values in consonance with those reported for quinoa due to high content and quality of proteins between 15.6–18.7 % with a wide amino acid spectrum, rich in arginine and lysine, and unsaturated fatty acids (approximately 85 %) mainly linoleic (18:2n-6, Ω6) (58–61 %), oleic acid (18:1n-9) (18–20 %) and α-linolenic acid (18:3n-3, Ω3) (6–8 %). Mineral composition showed high contents of mainly potassium, phosphorous and magnesium (908–1323, 516.2–582.9 and 182–232 mg 100 g−1 dw respectively). The main sugar was sucrose (ca. 1.5 %), with low fructose and glucose content. All varieties showed low saponin contents (≤0.9 %). Results indicate that under Southern European agri-environmental conditions the studied varieties have nutritional values according to composition traits reported for quinoa.