Content of Selected Vitamins and Antioxidants in Colored and Nonpigmented Varieties of Quinoa, Barley, and Wheat Grains

Abstract

Abstract The diversity in human diets that can be reached by proper use of different crops and varieties, including some underutilized ones, is a potentially powerful strategy to ensure food security and prevent serious health problems caused by current diets that are often not fulfilling nutritional requirements. In the framework of this research, the content of tocopherols and tocotrienols, thiamine, riboflavin, pyridoxine, and superoxide dismutase in nine varieties of quinoa, both colored and nonpigmented, obtained from 4 different countries, was investigated and compared to the content of the same vitamins and antioxidants in barley and wheat, both colored and nonpigmented, cultivated in the same experimental field. The aim of this work was to create a crop diversity strategy and encourage the consumption of underutilized crops to ensure that the human diet fulfills nutritional requirements. The contents of vitamin B1, B2, B6, tocopherol, and tocotrienol isomers and superoxide dismutase were determined via HPLC; imaging techniques were used to evaluate the seed color. Quinoa grains had the greatest concentration of tocopherol isomers and activity, represented mainly by α‐tocopherol and γ‐tocopherol. Wheat and barley seeds had substantial concentrations of tocopherols and tocotrienols. The concentration of riboflavin was greater in barley and wheat than in quinoa, the concentrations of pyridoxine and thiamine were variety‐dependent in all grains. Quinoa grains had greater concentration of superoxide dismutase compared to wheat and barley. The richness of each variety and crop should be recognized and used integrally to improve the diet quality. Practical Application Nutritional potential of crops was evaluated from the viewpoint of selected vitamins and antioxidants to create a well‐balanced diet. Combined use of both traditional (wheat, barley) and underutilized crops (quinoa) is recommended. HPLC methods and image analysis were successfully used as viable tools for food quality determination.