White and whole wheat flour breads: composition and simultaneous exposure to group B trichothecenes

The study aimed to determine the profile of group B trichothecenes (TCTBs), to estimate the daily exposure to them and to evaluate the relationship with the composition of different types of sliced wheat bread. A method for simultaneous determination of the TCTBs (deoxynivalenol (DON), 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, deoxyinivalenol-3-glucoside (DON-3G) and nivalenol) was validated and applied to determination in six types of sliced bread from the same factory.

The method's recovery ranged from 83.0% to 100.7%. There was co-occurrence of at least two TCTBs, and the DON levels were higher than 1 mg kg^-1 in 36.7% of the samples. The estimated daily exposure of total TCTBs ranged from 1.3- to 4.4-fold higher than the current DON level recommended by sanitary authorities worldwide. Females were the most exposed to TCTBs, particularly teenagers. The contamination in whole-sliced bread was 1.3-fold higher than in white-sliced bread. Principal components analysis indicated covariance patterns between DON-3G and the acetylate derivatives associated with fiber and protein, while DON was associated with lipid content.

Although this study is limited considering the context of consuming manufactured whole or white sliced bread, it confirmed the evidence of co-contamination and interconversion among TCTBs. It could contribute to the ongoing discussion regarding the maximum tolerable level restricted to DON as a means of ensuring mitigating exposure to these compounds. © 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.