Uncommon occurrence ratios of aflatoxin B1, B2, G1, and G2 in maize and groundnuts from Malawi

Matumba, L and Sulyok, M and Njoroge, S M C and Ediage, E N and Poucke, C V and Saeger, S D and Krska, R (2015) Uncommon occurrence ratios of aflatoxin B1, B2, G1, and G2 in maize and groundnuts from Malawi. Mycotoxin Research, 31 (01). pp. 57-62. ISSN 1867-1632

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Abstract

We report an unusual aflatoxin profile in maize and groundnuts from Malawi, with aflatoxin G1 found routinely at equal or even higher levels than aflatoxin B1. Aflatoxin B1 (AFB1) ratio in a contaminated sample is generally greater than 50 % of total aflatoxin (sum of aflatoxin B1, B2, G1, and G2). In Malawi, the aflatoxin occurrence ratios were determined by examining LC-MS/MS and HPLC fluorescence detection (FLD) data of 156 naturally contaminated raw maize and 80 groundnut samples collected in 2011 and 2012. Results showed that natural aflatoxin occurrence ratio differed. In 47 % of the samples, the concentration of AFG1 was higher than that of AFB1. The mean concentration percentages of AFB1/AFB2/AFG1/AFG2 in reference to total aflatoxins were found to be 47:5:43:5 %, respectively. The AFG1 and AFB1 50/50 trend was observed in maize and groundnuts and was consistent for samples collected in both years. If the AFB1 measurement was used to check compliance of total aflatoxin regulatory limit set at 10, 20, 100, and 200 μg/kg with an assumption that AFB1 ≥ 50 % of the total aflatoxin content, 8, 13, 24, and 26 % false negative rates would have occurred respectively. It is therefore important for legislation to consider total aflatoxins rather than AFB1 alone.

Item Type: Article
Divisions: RP-Grain Legumes
CRP: CGIAR Research Program on Grain Legumes
Uncontrolled Keywords: Aflatoxin ratios, Maize, Groundnuts, Malawi
Subjects: Mandate crops > Groundnut
Others > Maize
Depositing User: Mr Ramesh K
Date Deposited: 03 Mar 2016 03:40
Last Modified: 21 Oct 2016 08:42
URI: http://oar.icrisat.org/id/eprint/9351
Official URL: http://dx.doi.org/10.1007/s12550-014-0209-z
Projects: UNSPECIFIED
Funders: UNSPECIFIED
Acknowledgement: The authors are grateful for the following: (1) the Federal Country Lower Austria and the European regional development fund of the European Union for the LC-MS/MS system at IFA-Tulln; (2) the donation of HPLC system and starter-park reagents by EU to the Dept. of Agricultural Research Services (Malawi) through a SADC-Food Safety Capacity Building on Residues Control Project; (3) the Republic of Malawi (Ministry of Agriculture and Food Security), the World Bank, and the Norwegian Ministry of Foreign Affairs for co-financing the first author’s travel costs and living expenses abroad; (4) Prof. Dr. Maurice Monjerezi of the University of Malawi for kindly designing a map depicting sampling sites; and (5) invaluable technical assistance provided by L. Singano, T. Mhango, H. Mbalame, C. Gadaga, D. Kalima, D. Bwanamiri, M. Kalitsiro, C. Tchuwa
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