Maize-dependent populations in sub-Saharan Africa are continually exposed to aflatoxin poisoning owing to their regular consumption of this dietetic cereal. Being a staple in Kenyan households, consumption of maize-based meals is done almost daily, thereby exposing consumers to aflatoxicoses. This study assessed awareness levels, knowledge disparities, and perceptions regarding aflatoxin contamination at the post-harvest phase among farmers in the Rift Valley Region of Kenya. Households were randomly selected using a geographical positioning system (GPS) overlay of the agro-ecological zones within Uasin Gishu and Elgeyo Marakwet counties. Face-to-face interviews were conducted in 212 smallholder and large-scale farms. The study documented the demographic profiles of farmers and knowledge, awareness, and perceptions of aflatoxin contamination using a pre-designed structured questionnaire. Most farmers were familiar with aflatoxins and the adverse effects they present to health (61.32%). Almost all the farmers (94.37%) were aware of storage molds and food-spoilage fungi. However, few farmers adopted good post-harvest practices (PHPs), such as avoiding premature harvests (49.8%), using well-ventilated storage spaces (44.6%), grain sorting (30.5%), proper drying of maize (17.8%), and using hermetic bags for storage (30.5%). Conclusively, intensified farmer education is required to train farmers on good PHPs to protect their maize from aflatoxigenic fungi and aflatoxin accumulation.

The present study combined Fourier-Transform Infrared Spectroscopy (FT-IR) analysis with high resolution liquid chromatography tandem mass spectroscopy equipped with an electrospray ionization source (LC-ESI-MS/MS) in the screening and quantification of four naturally occurring aflatoxins (AFs) AFB1, AFB2, AFG1 and AFG2 in milled hybrid maize cultivars (n = 171) from selected counties in the Rift-Valley region of Kenya. Samples were extracted in a single-step process using acetonitrile/water 80:20 v/v in 0.5% formic acid without further clean-up steps. Aflatoxins were analyzed in both positive and negative ionization modes using the multi-reaction monitoring (MRM) acquisition process that allowed confirmation and quantification of the aflatoxins in a single run. The MRM mode was utilized for quantitative analysis while qualitative analysis was done using the enhanced product ion mode. Aflatoxin presence was detected in the following ranges and frequencies: AFB1 (0-9.36μg/kg), AFB2 (0-6.62μg/kg), AFG1 (0-7.72μg/kg) and AFG2 (0-9.18μg/kg). Additional mycotoxins recovered included the following; sterigmatocystin (0-8.3μg/kg) and deoxynivalenol (0-7.3μg/kg). In overall, low amounts of aflatoxins were recovered from the milled maize samples with an additional low total aflatoxin content above the stipulated regulatory limit of 10μg/kg. Given that slow continued exposure to aflatoxins (especially in low amounts) has been proven to be a leading cause of various forms of cancer, urgent intervention measures and national surveillance programs ought to be introduced to protect consumers from gradual aflatoxin poisoning emanating from the consumption of contaminated Kenyan maize.