Occurrence of Aspergillus Species and Aflatoxin Contamination in Raw and Roasted Peanuts from Formal and Informal Markets in Eldoret and Kericho Towns, Kenya

Nyirahakizimana, H and Mwamburi, L and Wakhisi, J and Mutegi, C K and Christie, M E and Wagacha, J M (2013) Occurrence of Aspergillus Species and Aflatoxin Contamination in Raw and Roasted Peanuts from Formal and Informal Markets in Eldoret and Kericho Towns, Kenya. Advances in Microbiology, 3 (4). pp. 333-342. ISSN 2165-3410

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The population and diversity of fungal species and levels of aflatoxin contamination were investigated in 228 marketed peanut samples; 140 from formal and 88 from informal markets, in Kericho and Eldoret towns of Kenya. Ground peanut samples were cultured on Modified Dichloran Rose Bengal (MDRB) agar while aflatoxin level was quantified based on indirect competitive ELISA. Correlation between the incidence of major aflatoxin-producing fungal species and aflatoxin levels was also established. Fungal species commonly isolated from the peanut samples included Aspergillus flavus L strain, A. flavus S strain, A. parasiticus, A. tamarii, A. caelatus, A. alliaceus (all of Aspergillus section Flavi) and A. niger. Fungi isolated in low frequency included Fusarium spp., Penicillium spp., Mucor spp. and Rhizopus spp. Aflatoxin levels in peanut products ranged from 0 to 2345 μg/kg in raw peanuts, 0 to 382 μg/kg in roasted coated peanuts, and 0 to 201 μg/kg in roasted de-coated peanuts. Overall, levels of total aflatoxin were higher in samples from informal (mean = 97.1 μg/kg) than formal (mean = 55.5 μg/kg) market outlets. There was a positive and significant correlation (R2 = 0.63; p ≤ 0.05) between aflatoxin levels and the major aflatoxin producing fungi in raw peanuts from formal markets in Eldoret town. Additionally, total aflatoxin in raw peanut samples from informal markets in Kericho was positively and significantly correlated (R2 = 0.81; p ≤ 0.05) to the population of A. flavus (L and S strains). In roasted coated peanuts sampled from formal market outlets in Eldoret, aflatoxin levels correlated positively and significantly (R2 = 0.37; p ≤ 0.05) with A. flavus S strain. There is need to create awareness among peanut traders and consumers on proper handling of peanuts and health risks associated with consumption of unsafe peanut products.

Item Type: Article
Uncontrolled Keywords: Aflatoxin; Aspergillus Section Flavi; Peanuts; Peanut Market Outlets
Subjects: Mandate crops > Groundnut
Depositing User: Mr Sanat Kumar Behera
Date Deposited: 27 Jul 2013 08:36
Last Modified: 11 Mar 2014 08:32
URI: http://oar.icrisat.org/id/eprint/6989
Official URL: http://dx.doi.org/10.4236/aim.2013.34047
Projects: Peanut Collabo- rative Research Support Program
Funders: United States Agency for International Development
Acknowledgement: This research was funded in part by the Peanut Collabo- rative Research Support Program (Peanut CRSP) funded by USAID under cooperative agreement USAID ECG- A-00-07-00001-00. The authors express their gratitude to all peanut traders who participated in the study.
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