Moses Osiru, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)
Managing Aflatoxins Pre- and PostHarvest
Preharvest contamination control is critical to success because once infection occurs, it is difficult to completely eliminate it. This stage of control focuses on controlling critical factors that predispose crops to mycotoxin contamination which although difficult in nature, have high potential to mitigate the contamination and its effects. Postharvest contamination is related to preharvest accumulation as higher aflatoxin loads at harvest provide inoculum sources for subsequent contamination during storage. After harvest, Aspergillus infection and growth is likely if crops are not dried adequately within a short period of time. Rain on drying peanuts also often results in contamination. Postharvest practices such as physical separation (sorting) of kernels are very effective in the reduction of mycotoxin levels, with reductions of up to 91% reported. Winnowing, washing, crushing, de-hulling and drying are other practices that can reduce contamination.