Fungal contaminants and aflatoxins in maize from lower eastern region in Kenya

Aflatoxin outbreaks have been reported in the lower eastern region of Kenya since 1978. These outbreaks have caused a lot of concern as some have led to loss of lives. This study was conducted to assess the extent of fungal contaminants in maize in the region and more importantly the exposure to aflatoxicosis due to Aspergillus spp contamination. Seventy two maize samples were purchased from farmers (24 samples from each county) interviewed in the survey that was conducted in October 2012. The samples were first assessed for general fungal contaminants and then for Aspergillus spp. contaminants. Aspergillus spp. were isolated using Czapek Dox agar medium. Fusarium, Aspergillus and Penicillium were the predominant fungal species that were isolated and for the Aspergillus species, A. niger and A. flavus were most predominant. Aflatoxin quantification was carried out using LC-MS analysis. The findings showed that aflatoxin B1 was more predominant than aflatoxin B2, aflatoxin G1 and aflatoxin G2. More than 70 % of the samples were fit for human consumption since they had aflatoxin levels less than 10ng/g while the highest had 128ng/g. Poor post-harvest practices might be the main source of Aspergillus contamination which leads to high level of aflatoxin as revealed in this study. Although most farmers are aware of the aflatoxin problem, continuous mycotoxin awareness campaign by Government and other stakeholders is recommended until everybody along the maize farming and trading value chains is aware. This will significantly contribute to eradication of this perennial aflatoxin problem in the region.