Transformation of deoxynivalenol and its acetylated derivatives in Chinese steamed bread making, as affected by pH, yeast, and steaming time.

We hereby report the transformation of deoxynivalenol (DON) and its acetylated derivatives (3-ADON and 15-ADON) by spiking targeted mycotoxins to Fusarium mycotoxin-free flour in the process of making Chinese steamed bread (CSB). The impacts of pH, yeast level, and steaming time on the transformation of 3-ADON to DON were investigated. DON, 3-ADON, and 15-ADON were analyzed by UPLC-MS/MS. Spiked DON was stable throughout the CSB making process. Spiked 3-ADON and 15-ADON were partially deacetylated and transformed to DON during kneading (54.1-60.0% and 59.3-77.5%, respectively), fermentation (64.0-76.9% and 78.2-91.6%, respectively), and steaming (47.2-52.7% and 52.4-61.9%, respectively). The ADONs level increased after steaming compared with their level in the previous step. The pH level and steaming duration significantly (P<0.05) affected the conversion of 3-ADON during the CSB making process. Briefly, alkaline conditions and short steaming times favored the deacetylation of 3-ADON. The level of yeast did not remarkably (P<0.05) alter the transformation between ADONs and DON.