A new study found that rising carbon dioxide levels significantly change wheat protein composition, affecting baking quality and health. Researchers said, “The reduced concentration of gluten proteins was associated with poorer baking quality.” As CO2 levels climb, experts suggest breeding wheat varieties that maintain quality despite these environmental changes.
Higher levels of carbon dioxide in the atmosphere can significantly alter the protein composition of wheat, impacting not only baking quality but also the tolerability of wheat products, a new study has found.
Findings published in the journal Food Chemistry suggest that crop adaptation under climate change should focus not only on high yields but also on quality characteristics such as protein composition.
Researchers, led by the Leibniz Institute for Food Systems Biology at the Technical University of Munich in Germany, said that globally, carbon dioxide (CO2) levels have increased from 340 parts per million in 1980 to about 425 parts per million in 2024.
Wheat, one of the world’s most important staple foods, will also grow under significantly higher CO2 concentrations in the future, which could go up to 600 parts per million by 2050, they said.
The team grew ten cultivated varieties of winter wheat under realistic growing and environmental conditions. They exposed some of the plants to an elevated CO2 concentration (546 parts per million), while others grew under current CO2 conditions.
After harvest, the researchers analysed the composition of wheat proteins in the various grain samples using a high-resolution mass spectrometric method they developed themselves. Proteins such as amylase/trypsin-inhibitors, puroindolines, and gluten proteins, as well as celiac disease-active peptides, were focused on.
Overall, the content of amylase/trypsin-inhibitors increased under elevated CO₂ conditions, while that of puroindolines, gluten proteins, and certain celiac disease-active peptides—which may be produced from gluten proteins during digestion—decreased. The increased levels of amylase/trypsin-inhibitors (ATIs) could negatively impact human health.
“However, the extent of these changes depended largely on the specific wheat cultivar,” Sabrina Geisslitz, principal investigator and research associate at the Leibniz Institute, said.
“Our results also showed that the reduced concentration of gluten proteins was associated with poorer baking quality,” Geisslitz said.
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, added, “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’s results underscore how important it is to identify and breed cultivated varieties of wheat that maintain high baking quality, even under increasing CO2 concentrations while containing as few potentially intolerable proteins as possible, the researchers said.
“Rising atmospheric CO2 concentrations may alter the protein composition of wheat and thereby affect grain quality,” the authors wrote.
“The findings highlight the importance of identifying cultivars (cultivated variety) with low levels of ATI and celiac disease-active peptides while maintaining good baking quality under rising CO2,” they said.