Fungal and bacterial metabolites of stored maize (Zea mays, L.) from five agro-ecological zones of Nigeria

• Published in: Mycotoxin research Vol. 30; no. 2; pp. 89 - 102
• Main Authors: Adetunji, Modupeade, Atanda, Olusegun, Ezekiel, Chibundu N, Sulyok, Michael, Warth, Benedikt, Beltrán, Eduardo, Krska, Rudolf, Obadina, Olusegun, Bakare, Adegoke, Chilaka, Cynthia A
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.05.2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Aflatoxins; agroecological zones; Agronomy; Bacteria; Bacteria - metabolism; Bacterial Toxins - analysis; Biological and medical sciences; Biomedical and Life Sciences; Chemistry/Food Science; Chromatography, Liquid; Contamination; Corn; correlation; deoxynivalenol; Ecology; Edible Grain - chemistry; European Union; Food industries; Food Safety; Food toxicology; fumonisins; Fundamental and applied biological sciences. Psychology; Fungi; Fungi - metabolism; Grain; Life Sciences; Medical Microbiology; Medical sciences; Medicine/Public Health; Metabolites; Microbiology; Mycotoxins; Mycotoxins - analysis; Nigeria; Original Paper; Plant poisons toxicology; Public health; savannas; stored grain; Tandem Mass Spectrometry; Toxicology; Toxins; Zea mays; Zea mays - chemistry; Nigeria; Maize; Aflatoxin; Mycotoxin; Microbial metabolite; Toxin
• ISSN: 0178-7888; 1867-1632
• DOI: 10.1007/s12550-014-0194-2

Seventy composite samples of maize grains stored in five agro-ecological zones (AEZs) of Nigeria where maize is predominantly produced were evaluated for the presence of microbial metabolites with the LC-MS/MS technique. The possible relationships between the storage structures and levels of mycotoxin contamination were also evaluated. Sixty-two fungal and four bacterial metabolites were extracted from the grains, 54 of which have not been documented for maize in Nigeria. Aflatoxin B₁ and fumonisin B₁ were quantified in 67.1 and 92.9 % of the grains, while 64.1 and 57.1 % exceeded the European Union Commission maximum acceptable limit (MAL) for aflatoxin B₁ and fumonisins, respectively. The concentration of deoxynivalenol was, however, below the MAL with occurrence levels of 100 and 10 % for its masked metabolite, deoxynivalenol glucoside. The bacterial metabolites had low concentrations and were not a source of concern. The storage structures significantly correlated positively or negatively (p < 0.01 and p < 0.05), respectively with the levels of grain contamination. Consumption of maize grains, a staple Nigerian diet, may therefore expose the population to mycotoxin contamination. There is need for an immediate action plan for mycotoxin mitigation in Nigeria, especially in the Derived Savannah zone, in view of the economic and public health importance of the toxins.