Rising atmospheric carbon dioxide (CO₂) concentrations could significantly alter the protein composition of wheat affecting its baking quality and potentially influencing the tolerability of wheat based foods according to a new study published in the journal Food Chemistry.
The research led by the Leibniz Institute for Food Systems Biology at the Technical University of Munich found that elevated CO₂ levels changed the concentrations of several important wheat proteins. The extent of these changes varied among wheat varieties, highlighting the need to consider food quality alongside crop yields when developing climate resilient wheat varieties.
Wheat is one of the world’s most important staple crops, providing a substantial share of the calories and protein consumed globally. As climate change continues to alter growing conditions, scientists are examining how rising atmospheric CO₂ levels could affect not only agricultural production but also the nutritional and functional properties of food.
Atmospheric CO₂ concentrations have increased from around 340 parts per million (ppm) in 1980 to approximately 425 ppm in 2024. Depending on future socioeconomic and emissions trends, concentrations could approach 600 ppm by 2050.
Examining wheat under elevated CO₂
To investigate how higher CO₂ concentrations affect wheat proteins, researchers cultivated 10 winter wheat varieties under realistic growing conditions. Some plants were exposed to elevated CO₂ levels of 546 ppm, while others grew under current atmospheric conditions.
After harvesting the wheat, the team used a high-resolution mass spectrometry method to examine the protein composition of the grain.
The analysis focused on several groups of proteins, including amylase/trypsin inhibitors, puroindolines and gluten proteins. Researchers also examined peptides associated with coeliac disease, which can form when gluten proteins are broken down during digestion.
The results revealed distinct changes in protein composition under elevated CO₂ conditions.
Different proteins respond differently
The researchers found that concentrations of amylase/trypsin inhibitors generally increased when wheat was grown under elevated CO₂ levels. In contrast, concentrations of puroindolines, gluten proteins and certain coeliac disease active peptides decreased.
However, the scale of these changes depended substantially on the wheat variety being studied.
The reduction in gluten proteins was also associated with poorer baking quality. Gluten plays an important role in dough elasticity, structure and its ability to retain gas during fermentation, all of which influence the texture and volume of baked products.
These findings suggest that rising CO₂ levels could affect the suitability of some wheat varieties for breadmaking and other food applications even if the crops continue to grow successfully.
Potential implications for wheat related disorders
The study also raises questions about how climate driven changes in wheat proteins could affect people with wheat-related disorders.
Coeliac disease is an autoimmune condition in which gluten triggers an immune response that damages the small intestine. The researchers observed changes in certain peptides associated with the disease, but the findings do not establish that wheat grown under elevated CO₂ would be safer or more harmful for people with coeliac disease.
Changes in amylase/trypsin inhibitors could also be relevant to wheat related health conditions. However, the biological and immunological significance of the observed differences remains uncertain.
Further research is needed to determine whether these changes in protein composition translate into meaningful differences in human health. The study did not demonstrate that elevated CO₂ directly increases or decreases the risk of developing wheat related disorders.
Breeding wheat for a changing climate
The findings highlight the importance of evaluating crop quality as well as productivity when developing varieties suited to future climate conditions.
Plant breeding programmes have traditionally placed considerable emphasis on improving yields, disease resistance and tolerance to environmental stress. The researchers suggest that maintaining desirable protein composition and baking performance should also become important selection criteria.
Identifying wheat varieties that retain their baking quality under higher CO₂ concentrations could help food producers adapt to changing growing conditions. Researchers may also be able to identify varieties with protein profiles that are more suitable for specific food applications.
The study involved scientists from the Leibniz Institute for Food Systems Biology, the Karlsruhe Institute of Technology, the Bavarian State Research Center for Agriculture and Forschungszentrum Jülich.
Although the findings provide evidence that rising CO₂ levels can reshape wheat protein composition further studies are needed to establish how these changes will develop under future field conditions and what they could mean for food processing and human health.
As atmospheric CO₂ concentrations continue to rise understanding these effects will be important for protecting both the quantity and quality of one of the world’s most widely consumed staple foods.