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ARS and Frito-Lay Chip Away at FumonisinsBy Sharon Durham
April 1, 2002
Agricultural Research Service pharmacologist Kenneth Voss and chemist Stephen Poling, along with scientists at Frito-Lay, Inc., are collaborating to determine what happens to fumonisins during the manufacture of tortilla corn chips. Fumonisins are natural toxins, known as mycotoxins, that are made by the fungus Fusarium moniliforme and other types of Fusarium fungi found worldwide in corn.
The FDA recently issued guidelines for fumonisin concentrations in corn used for human food products. Depending upon the product involved, the permissible levels range from 2-4 parts per million. Fumonisin levels in corn and corn products in the United States are relatively low, but are quite high in some other countries where corn, often of lower quality, is a diet staple.
In their studies, Voss and Poling measured a specific fumonisin, B1, in raw corn, the intermediate products, fried chips and waste byproducts. During processing, most of the fumonisins in the raw corn are diverted into waste byproducts, lowering the concentration of fumonisins in the tortilla chips by as much as 80 percent.
The key to reducing fumonisin levels in the tortilla chips, according to Voss, was nixtamalization and rinsing. Nixtamalization involves cooking and steeping the corn in lime-water. The cooked kernels are then rinsed with fresh water to remove the loosened hulls before being ground into masa. The masa serves as a base for fried chips and is an ingredient in other foods.
A chemically modified type of fumonisin, called hydrolyzed fumonisin, forms during nixtamalization. Most of the hydrolyzed fumonisins that are formed during chip production remained in the lime-water and, like fumonsin B1, were diverted from the tortilla chip product.
Given the ongoing food safety concerns regarding fumonisins, efforts to better understand the fate of fumonisins and find ways of reducing their levels in foods are continuing.
ARS is the chief scientific research agency of the U.S. Department of Agriculture.