Aflatoxins are highly toxic compounds produced mainly by Aspergillus section Flavi on a wide range of food commodities, including groundnuts. Infestation occurs during both the pre-harvest and post-harvest stages of crop production, which has affected the quality and safety of groundnuts and groundnut-based products. The objective of this study was to determine total aflatoxin concentration in groundnut samples collected from farmers in four major groundnut growing regions of Kenya, the Rift Valley (Baringo and Elgeyo-Marakwet Counties) and Western region (Bungoma and Siaya Counties). A total of forty groundnut samples were evaluated for total aflatoxin concentration using an enzyme linked immunosorbent assay (ELISA). Data were analyzed using one-way analysis of variance (ANOVA) and means separated by Duncan's Multiple Range Test. All samples except one were positive for aflatoxin contamination. The total aflatoxin levels in the positive samples ranged between 0-113 ppb. Results indicated relatively low levels of total aflatoxin in samples from Baringo and Elgeyo-Marakwet Counties (2.12 ppb on average) that are fit for human consumption based on 10 ppb required by Kenya Bureau of Standards (KEBS) guidelines. However, high levels of total aflatoxin (13.88 ppb on average) were detected in samples from Bungoma and Siaya Counties. There was significant variation (p =0.005) in levels of aflatoxin concentration across the different counties in this study. Groundnut samples from the Western region had higher aflatoxin concentration far beyond the KEBS standard of 10 ppb and hence pose grave danger to groundnut consumption and marketing. There is, therefore, an urgent need to develop and implement effective strategies for managing aflatoxins’ contamination in groundnuts in this region.

Keywords: Aflatoxins, Aspergillus species, Groundnuts, Occurrence, Human poisoning, ELISA