title: Uncommon occurrence ratios of aflatoxin B1, B 2, G 1, and G 2 in maize and groundnuts from Malawi.
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.
authors.affiliation: Faculty of Pharmaceutical Sciences, Department of Bioanalysis, Ghent University, Ottergemsesteenweg 460, 9000, Ghent, Belgium, alimbikani@gmail.com.
authors.forename: Limbikani
authors.initials: L
authors.lastname: Matumba
authors.forename: Michael
authors.initials: M
authors.lastname: Sulyok
authors.forename: Samuel M C
authors.initials: SM
authors.lastname: Njoroge
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Njumbe Ediage
authors.forename: Christof
authors.initials: C
authors.lastname: Van Poucke
authors.forename: Sarah
authors.initials: S
authors.lastname: De Saeger
authors.forename: Rudolf
authors.initials: R
authors.lastname: Krska
mesh_terms: D000348:Aflatoxins / Q000032:analysis*; D010367:Arachis / Q000737:chemistry*; D002853:Chromatography, Liquid; D005506:Food Contamination / Q000032:analysis*; D064088:Hazard Analysis and Critical Control Points / Q000379:methods; D008295:Malawi; D053719:Tandem Mass Spectrometry; D003313:Zea mays / Q000737:chemistry*
chemical_list: D000348:Aflatoxins