Beyond aflatoxins : unravelling the hidden mycotoxins in Kenyan maize

Mycotoxins are secondary metabolites of some filamentous fungi. When consumed in large quantities they cause death and in small quantities overtime, they can be carcinogenic, nephrotoxic, genotoxic, hepatotoxic and immunosuppressive. In Kenya, loss of life has been documented repeatedly from consumption of aflatoxin contaminated maize. These aflatoxicosis outbreaks have attracted attention from stakeholders in the maize value chain in attempts to finding lasting solutions to the aflatoxin problem. The registration and commercialization of a biocontrol formulation (Aflasafe KE01®) as an aflatoxins pre-harvest control technology and promotion of hermetic storage devices as a post-harvest control technology are commendable efforts in the fight against aflatoxins. However, beyond aflatoxins, there are numerous other mycotoxins currently neglected and are not regulated in Kenya. Without regulation, the public risks being exposed to these mycotoxins. This PhD generates data necessary to support legislative decisions for mycotoxins control by, (i) Unraveling mycotoxins present in Kenyan maize. (ii) Determining the source of these mycotoxins by evaluating the incidence of toxigenic Aspergillus and Fusarium occurring on maize kernels. (iii) As a mitigation strategy, local open pollinated maize varieties are compared with commercial hybrids maize varieties to evaluate which variety is less susceptible to mycotoxin contamination. (iv) Evaluating the toxicity of selected emerging mycotoxins to vertebrates using larval zebrafish. The findings of this PhD reveal that Kenyan maize is laden with multiple mycotoxins, local open pollinated maize varieties are less susceptible to mycotoxin contamination compared to commercial hybrids. Emerging mycotoxins have deleterious health effects on zebrafish extrapolatable to vertebrates. In conclusion, a robust mycotoxin regulatory framework should be enacted and research on mycotoxins mitigation and food safety should be intensified