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United States Department of Agriculture

Agricultural Research Service

Title: Occurrence of Fusarium Species and Mycotoxins in Nepalese Maize and Wheat and the Effect of Traditional Processing Methods on Mycotoxin Levels

Authors
item Desjardins, Anne
item Manandhar, Gyanu - NEPAL AGR RES COUNCIL
item Plattner, Ronald
item Maragos, Chris
item Shrestha, Krishna - NEPAL AGR RES COUNCIL
item McCormick, Susan

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 10, 2000
Publication Date: N/A

Interpretive Summary: To assess the safety of maize and wheat being used for human consumption in Nepal, we surveyed more than 100 samples of maize and wheat for Fusarium fungi and for several mycotoxins. We found that both Nepalese maize and wheat are infected with a number of Fusarium species that produce mycotoxins. Wheat samples contain no detectable mycotoxins, but approximately 20% of the maize samples contain mycotoxins above an acceptable limit of 1 ug/g. Our study also found that Nepalese women were able to detoxify contaminated maize by hand-sorting visibly diseased kernels, a practical, low-technology solution to this problem.

Technical Abstract: Maize (Zea mays) and wheat (Triticum aestivum) collected in the foothills of the Nepal Himalaya were analyzed for Fusarium species and mycotoxins: fumonisins, nivalenol (NIV), and deoxynivalenol (DON). Predominant species were Gibberella fujikuroi mating population A (F. moniliforme) in maize, and F. graminearum in maize and wheat; with G. fujikuroi mating population D (F. proliferatum), F. acuminatum, F. avenaceum, F. chlamydosporum, F. equiseti, F. oxysporum, F. semitectum, and F. torulosum also present. Strains of G. fujikuroi mating population A produced fumonisins, and strains of F. graminearum produced NIV or DON. By immunoassay or high performance liquid chromatography, fumonisins were >1000 ng/g in 22% of 76 maize samples. By immunoassay or fluorometry, NIV and/or DON were >1000 ng/g in 16% of maize samples, but were not detected in wheat. Fumonisins and DON were not eliminated by traditional fermentation for producing maize beer, but Nepalese rural and urban women were able to detoxify contaminated maize by hand-sorting visibly diseased kernels.

Last Modified: 11/26/2014
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