Effect of Aflasafe TZ01^® on Aflatoxin Reduction and Emerging Challenges with Fusarium Mycotoxins in Maize from Rural Tanzania

Aflatoxins are carcinogenic secondary metabolites produced by Aspergillus species and are common contaminants of many crops including maize. Atoxigenic Aspergillus flavus strains, formulated as biocontrol products such as Aflasafe^® TZ01, that comprises a mixture of four native atoxigenic strains, are used as pre-harvest agents to suppress toxigenic strains and reduce aflatoxin levels. This study assessed the intended and potential unintended impacts of Aflasafe^® TZ01 on mycotoxin contamination in maize. A total of 158 samples 79 from treated and 79 from untreated fields were collected from Chemba and Kiteto districts in Tanzania. Multi-mycotoxin analysis was conducted using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Detected toxins included aflatoxins (AFB1, AFB2, AFG1, AFG2), trichothecenes, and fumonisins (FB1, FB2, FB3). Non-parametric paired t-test analysis showed significant reductions in AFB1 (62%, p = 0.024) in treated samples. The mean concentrations of Fusarium mycotoxins such as NIV, T2, and ZEN were higher in treated maize. However, statistical analysis showed that these differences were only numerical trends, and were not significant (p > 0.05). These findings confirm the efficacy of Aflasafe^® TZ01 in reducing aflatoxins, while underscoring the importance of continued monitoring for other mycotoxins as part of integrated mycotoxin management strategies to mitigate both aflatoxins and co-occurring toxins.