LAUSR

Abstract A total of 67 cereal samples consisting of conventionally and organically produced corn, wheat and rice were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry to monitor the occurrence of type-B trichothecenes (deoxynivalenol (DON), nivalenol (NIV), 3-acetyldeoxynivalenol (3ADON), 15-acetyldeoxynivalenol (15ADON), fusarenon-X (FUS-X)), and deoxynivalenol-3-glucoside (D3G). The incidence rates were 94%, 88%, 86.5%, 31.3%, 29.8%, and 61.2% for DON, D3G, NIV, 3ADON, 15ADON, and FUS-X, respectively. The highest contamination levels of DON, D3G, NIV, 3ADON, and 15ADON were found in corn, followed by wheat and rice, whereas FUS-X exhibited high contamination in rice. Moreover, significant differences were observed between conventionally and organically produced corn samples, which revealed higher incidence and contamination levels of the target mycotoxins in organic samples rather than in conventional samples. A total of 93.6% of all DON-contaminated samples showed the transformation of DON to its glucosylated form, D3G, with average conversion rates of 14%, 17%, and 28% in rice, wheat, and corn samples, respectively. In addition, the co-occurrence of two or more different mycotoxins was observed in a high percentage of the analyzed samples. Therefore, the results indicated that a vigilant attitude should be adopted to reduce human exposure to all of these toxic compounds.