Influence of interstitial carbon dioxide on deoxynivalenol accumulation in stored wheat under varying Fusarium treatments and airtight storage conditions.

BACKGROUND: Temperature and moisture content are recognized as the main factors responsible for mycotoxin production in stored grain, while the role of gaseous environment, particularly interstitial CO2, remains unexplored. This study investigated the relationship between interstitial CO2 concentration (generated metabolically in air spaces between grain kernels) and deoxynivalenol (DON) production in stored wheat under varying moisture contents (13%, 15%, 17%, 20%, or 23%), Fusarium treatments (naturally infected, Fusarium-inoculated, disinfected, or disinfected + Fusarium-inoculated), and airtight durations (1, 3, 6, or 12 days).

RESULTS: Moisture was the dominant factor affecting both CO2 and DON production, explaining most of the observed variance. Fusarium inoculation significantly increased interstitial CO2 concentration, daily CO2 production (generated interstitially depending on airtight duration), and accumulated CO2 production (accumulated interstitially until the end of the storage period). Airtight duration significantly affected CO2 production and influenced DON concentrations. A significant positive correlation (r = 0.87, P < 0.001) between interstitial CO2 and log10-transformed DON concentration was obtained.

CONCLUSION: Wheat with <20% interstitial CO2 concentration remained below safety thresholds for DON concentration, and >30% interstitial CO2 was found in 60% of DON-contaminated samples, suggesting a cut-off for safe storage and that monitoring of interstitial CO2 concentration during grain storage may provide a helpful indication of the risk of grain quality loss. These findings offer a practical approach to minimizing DON accumulation in stored wheat. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.