Location: Toxicology & Mycotoxin ResearchTitle: Limited Surveys for Aflatoxin-Fumonisin Co-contamination of Maize-based Foods Available in the Southeastern U.S., 2015-2016
|XUE, KATHY - University Of Georgia|
|RILEY, RONALD - Former ARS Employee|
Submitted to: United States-Japan Cooperative Program in Natural Resources
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2018
Publication Date: 4/22/2018
Citation: Xue, K., Showker, A.J., Mitchell, T.R., Riley, R.T., Voss, K.A. 2018. Limited Surveys for Aflatoxin-Fumonisin Co-contamination of Maize-based Foods Available in the Southeastern U.S., 2015-2016. United States-Japan Cooperative Program in Natural Resources. p. 19.
Technical Abstract: Aflatoxins (AF) are mycotoxins produced by Aspergillus flavus and A. paraciticus. They are found in maize (Zea mais) and other crops. Aflatoxin B1 (AFB1) is a significant human health problem in developing countries. It is a potent human liver carcinogen, is associated with stunting in children, is immunotoxic, and causes other adverse effects. Other aflatoxins also exert adverse health effects, but are less potent. Fumonisins (FB) are mycotoxins produced by Fusarium species, mainly F. verticillioides and F. proliferatum. Like AF, they are common contaminates of maize with fumonisin B¬1 (FB1) being most common. FB1 causes various toxicities in animals including equine leukoencephalomalacia, porcine pulmonary edema, and liver and kidney cancer in rodents. The human health effects of FB are uncertain. Experimental and epidemiological evidence nonetheless suggest that FB are a risk factor for cancer, growth inhibition in children, and birth (neural tube) defects. AFB1 and FB1 exhibit different but complementary mechanisms of action: AFB1 is genotoxic (key event = epoxidation with subsequent DNA adduction) whereas the FB1 disrupts sphingolipid metabolism and sphingoid base- and sphingolipid-dependent functions (key event = inhibition of a key enzyme in ceramide biosynthesis). Moreover, FB1 has been shown to have liver cancer promoting activity in AFB1-exposed trout and rats. Co-exposure to these mycotoxins is therefore a growing human health concern. Little information is available on co-exposure through the consumption of maize-based foods in the U. S. Therefore, limited surveys of maize-based foods available to consumers in the southeastern U.S. was done. The food products were either purchased from local markets or obtained through internet sales. Survey 1 (2015) included 18 alkaline cooked (nixtamalized) maize flours and 23 maize meal samples. Survey 2 (2016) included the alkaline cooked products, polenta (n=7) and grits (n=10). AFB1 (13.4 µg/kg) was found one sample only, an alkaline cooked maize flour from Survey 1. In contrast to AF, FB were found in almost all samples. Mean total FB (FB1+2+3) concentrations in Survey 1 alkaline cooked maize flours and maize meals were 0.72 (±0.62 SD) mg/kg and 1.43 (±3.03) mg/kg, respectively. Total FB in Survey 2 averaged 0.23 (±0.30) mg/kg in grits and 0.43 (±0.32) mg/kg in polenta. The results of these limited surveys suggest that AF-FB co-contamination of maize products in the southeastern U.S. during 2015-2016 was not common.