|Voss, Kenneth - Ken|
Submitted to: Molecular Nutrition and Food Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/22/2004
Publication Date: 9/1/2004
Citation: Humpf, H., Voss, K.A. 2004. Effects of thermal food-processing on the chemical structure and toxicity of fumonisin mycotoxins. Molecular Nutrition and Food Research. 48:255-269. Interpretive Summary: Fumonisins are toxins produced by molds found in corn and in corn-based products. They are toxic to livestock and poultry, cause cancer in rodents, and it has been suggested that fumonisins are a risk factor for esophageal cancer or neural tube defectsin populations heavily dependent on contaminated corn as a dietary staple. It is therefore important to find methods of reducing fumonisin exposure in these populations. An ARS scientist collaborates in the writing of a review covering the salient points of fumonisin reduction during the cooking process. It has been found that cooking reduces the amount of fumonisin that can be measured in foods, although the amount of reduction is variable and depends on the cooking method, time, temperature, recipe and other factors. In some cases, a reduction in the amount of fumonisins measured in a food correlates with reduced toxicity. For example, cooking corn by nixtamalization (boiling and steeping in lime water) to make masa and tortilla products is beneficial. This is because a significant amount of fumonisins is removed from the corn and the products during boiling and steeping while some of the fumonisins remaining in the masa is converted to less toxic forms. The fate of fumonisins in corn cooked by baking, frying and extrusion, is unknown and it is possible that the fumonisins are either converted during cooking by one or more of these methods to other toxic compounds, or remain in the cooked food as unidentified, reaction products. Thus, a comprehensive research approach combining chemical analysis and toxicological assessment is needed to identify fumonisin reaction products and the cooking conditions that effectively reduce fumonisins levels and toxicity of food products.
Technical Abstract: Fumonisins are Fusarium mycotoxins found in corn and corn-based products. They are toxic to animals and are carcinogenic (liver and kidney) when fed to rodents. It is not known how fumonisins affect human health but they have been implicated as a cause of esophageal cancer and a risk factor for neural tube defects in populations dependent upon contaminated corn as a dietary staple. Therefore, it is important to find methods to reduce exposures in these populations. Cooking reduces the fumonisin concentration of food products although the amount of reduction is variable and influenced by the cooking method, time, temperature, recipe and other factors. Fumonisins are water soluble and nixtamalization (cooking in alkaline water) therefore lowers fumonisin content of nixtamalized food products provided the cooking liquid is discarded. However, the chemical fate of fumonisins in foods cooked by baking, frying, extrusion or other methods is not well understood. Specifically, it is not known if the measured reductions in fumonisin concentration therein resulted from thermal decomposition of the mycotoxin, formation of novel, biologically active compounds, or fumonisin binding to compounds in the food matrix. The extent to which any of these possibilities might or might not reduce potential toxicity depends upon the bioavailability and inherent toxicity of the reaction products. Therefore, an integrated approach combining chemical analyses and toxicological assessment of the cooked products are needed to determine the fate of fumonisins in foods and the extent to which cooking reduces toxicity.