Depending on the cultivar, higher concentrations of carbon dioxide (CO₂) in the atmosphere can significantly alter the protein composition of wheat. This affects not only baking quality but potentially also the tolerability of wheat products. This is the conclusion of a new study led by the Leibniz Institute for Food Systems Biology at the Technical University of Munich. According to the study, the adaptation of crops to climate change should in the future focus not only on high yields but also on quality characteristics such as protein composition.
As a result of climate change, the global CO₂ concentration in the atmosphere has risen from around 340 ppm in 1980 to about 425 ppm in 2024. Depending on future socioeconomic developments, it could rise to around 600 ppm by 2050. Wheat, one of the world's most important staple foods, will also grow under significantly higher CO₂ concentrations in the future.
So far, there have been only a few field trials
To date, however, only a few field trials have investigated how elevated CO₂ concentrations affect the protein composition of wheat. To fill this knowledge gap, the interdisciplinary team of researchers cultivated ten winter wheat cultivars under realistic growing and environmental conditions. They exposed some of the plants to an elevated CO₂ concentration (eCO₂, 546 ppm). The other plants grew under current CO₂ conditions.
After harvest, the researchers analyzed the composition of wheat proteins in the various grain samples using a high-resolution mass spectrometric method they had developed themselves. They focused on proteins such as amylase/trypsin-inhibitors, puroindolines, and gluten proteins, as well as celiac disease-active peptides.
Changes in Protein Composition with Consequences
In general, the content of amylase/trypsin-inhibitors increased under elevated CO₂ conditions. In contrast, the concentrations of puroindolines, gluten proteins, and certain celiac disease-active peptides—which may be produced from gluten proteins during digestion—decreased. "However, the extent of these changes depended largely on the specific wheat cultivar," says Sabrina Geisslitz, principal investigator and research associate in Katharina Scherf's research group at the Leibniz Institute. "Our results also showed that the reduced concentration of gluten proteins was associated with poorer baking quality," the scientist added.
Katharina Scherf, head of the Food Biopolymer Chemistry research group at the Leibniz Institute and professor of Food Biopolymer Systems at the TUM School of Life Sciences, adds: "The observed changes in amylase/trypsin-inhibitors and certain celiac disease-active peptides could also be relevant in the long term for wheat-related diseases. However, further studies are needed to clarify the actual biological and immunological significance of these differences."
The study results underscore how important it is to identify and breed wheat cultivars that maintain high baking quality even under rising CO₂ concentrations while containing as few potentially intolerable proteins as possible.
In addition to researchers from the Leibniz Institute, the interdisciplinary team included scientists from the Karlsruhe Institute of Technology, the Bavarian State Research Center for Agriculture, and the Forschungszentrum Jülich.
Publication: Geisslitz S, Kaemper C, Norwig MC, Fechner A, Knopf O, Muller O, Geyer M, Hartl L, Scherf KA. Elevated CO₂ induces cultivar-dependent changes in wheat proteins linked to wheat-related disorders and baking quality. Food Chem. September 20, 2026;530:151161. doi: 10.1016/j.foodchem.2026.151161. https://doi.org/10.1016/j.foodchem.2026.151161
Funding: The project was funded by the Federal Ministry of Agriculture, Food, and Regional Identity (BMLEH) based on a resolution of the Bundestag of the Federal Republic of Germany through the Federal Office for Agriculture and Food (BLE) as part of the Innovation Promotion Program. Project number 2818404B18 (BigBaking). Co-funded by the European Union (ERC, GLUTENOMICS, 101040437). Views and opinions expressed are solely those of the author(s) and do not necessarily reflect those of the European Union or the European Research Council Executive Agency. Neither the European Union nor the funding agency can be held responsible for this. Open-access funding was made possible and organized by the DEAL project.
