Multimycotoxin analysis of sorghum (Sorghum bicolor L. Moench) and finger millet (Eleusine coracana L. Garten) from Ethiopia

Abstract

Abstract The natural contamination of sorghum and finger millet by toxigenic fungi and associated mycotoxins has been studied. All the tested sorghum and finger millet samples were found to be contaminated by Fusarium and Aspergillus species. Sorghum was considerably more likely to be contaminated by both genera than finger millet. Penicillium, Alternaria, Rhizopus and Epicoccum species were also present in both grains albeit at lower frequencies. Multimycotoxin analysis using LC–MS/MS revealed the contamination of sorghum and finger millet by 84 and 62 metabolites, respectively. The prevalence of major mycotoxins was lower than 15% in sorghum except zearalenone that occurred in one third of the samples at average level of 44 μg/kg. In finger millet major mycotoxins occurred at a prevalence of 6–52% with zearalenone being the dominant and occurring at average level of 76 μg/kg. Aflatoxins B 1 , B 2 , G 1 , G 2 and M 1 were detected in at least one sorghum sample while only aflatoxins B 1 and G 1 were present in finger millet samples. The average aflatoxins B 1 and G 1 concentrations in sorghum have been higher than European standards. But the level of B 2 , G 2 and M 1 in sorghum and that of B 1 and G 1 in finger millet have been lower. Apart from aflatoxin precursors and other Fusarium metabolites, a broad range of additional metabolites were detected in sorghum and finger millet.