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United States Department of Agriculture

Agricultural Research Service


item Saunders, D
item Meredith, Filmore
item Voss, Kenneth - Ken

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 10/11/2000
Publication Date: 5/1/2000
Citation: N/A

Interpretive Summary: Fumonisins are made by common Fusarium molds. They are found in corn and corn-based foods. The most common fumonisin, fumonisin B1 (FB1), causes cancer in rats and mice. There is circumstantial evidence correlating high esophageal cancer rates of some human populations, for which corn is a dietary staple, with fumonisin exposure. It is therefore important from a food safety standpoint to develop strategies for controlling fumonisin levels in foods made from corn. Products made by dry milling, wet milling, and extrusion reportedly contain less measurable fumonisins than the corn from which they are made. We are studying what happens to FB1 during the commercial manufacture of tortilla chips, a popular snack food. Our preliminary findings show that a) the amount of FB1 measured in the fried chips is appreciably less than the amount in the corn from which they were made; b) reduction occurs primarily during the first step of the process, called nixtamalization (cooking and steeping the corn in lime water); and c) relatively little hydrolyzed FB1, a fumonisin byproduct of nixtamalization, is found in the finished chips. This preliminary information serves as a basis for more extensive studies on the fate of fumonisins during the commercial manufacture of corn based foods and ultimately for developing strategies for controlling fumonisin levels therein. Book chapter for the International Life Science Institute-NA International Conference on the Toxicology of Fumonisin, June 28-30, 1999, Arlington, VA.

Technical Abstract: Fumonisins are produced by Fusarium moniliforme and related fungi which commonly grow on corn. Fumonisin B1 (FB1) is toxic and carcinogenic to laboratory animals and causes the fatal diseases in horses and swine which are associated with F. moniliforme. Fumonisins are suspected human carcinogens. It has been reported that wet milling, dry milling, and extrusion processes used for producing corn-based products reduce fumonisin concentrations relative to the corn from which the products are made. Studies have been initiated to determine the fate of fumonisins, especially FB1, during commercial scale production of fried tortilla chips, a popular corn-based snack. Measurable FB1 concentrations in the tortilla chips are somewhat variable, but generally 40-80 percent lower than in the raw corn. FB2 concentrations followed a similar pattern. The initial step of the process called nixtamalization (cooking and steeping the corn in alkaline water) appears to be critical for achieving lower concentrations. Hydrolyzed FB1 (HFB1) was formed during nixtamalization, but most appeared to remain in the steep liquid or waste byproducts. Relatively low HFB1 concentrations, compared to FB1, were found in the tortilla chips. Studies to confirm these preliminary findings and to determine in more detail the fate of fumonisins during this commercial process are ongoing.

Last Modified: 10/16/2017
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