Mineral composition of durum wheat grain and pasta under increasing atmospheric CO2 concentrations

- Durum wheat genotypes were evaluated for free air CO2enrichmentat 400 and 570 ppm.
- Grain from ELE (570 ppm) showed significant decreases in micro- and macro-elements.
- In pasta from ELE, Ca, Cu, Zn and Mo decreased, Fe and Mn increased.
- The increases in Fe and Mn reflect different genotypic mineral distributions in grain.
- For mineral recommended daily allowances, pasta from ELE contributed less than AMB.

The concentrations of 10 minerals were investigated in the grain of 12 durum wheat genotypes grown under free air CO2 enrichment conditions, and in four of their derived pasta samples, using inductively coupled plasma mass spectrometry. Compared to ambient CO2 (400 ppm; AMB), under elevated CO2 (570 ppm; ELE), the micro-element and macro-element contents showed strong and significant decreases in the grain: Mn, −28.3%; Fe, −26.7%; Zn, −21.9%; Mg, −22.7%; Mo, −40.4%; K, −22.4%; and Ca, −19.5%. These variations defined the 12 genotypes as sensitive or non-sensitive to ELE. The pasta samples under AMB and ELE showed decreased mineral contents compared to the grain. Nevertheless, the contributions of the pasta to the recommended daily allowances remained relevant, also for the micro-elements under ELE conditions (range, from 18% of the recommended daily allowance for Zn, to 70% for Mn and Mo).