Grain quality characteristics of spring wheat (Triticum aestivum) as affected by free-air CO2 enrichment

► In a free-air CO2 experiment with wheat, thousand grain weight increased, while several grain quality parameters were negatively affected. ► Most importantly, concentrations of proteins and amino acids decreased and their compositions changed as well. ► The CO2-induced decrease in iron and calcium may aggravate nutrient deficiencies in terms of cereal-based diets.