
ARS and
Frito-Lay Chip Away at Fumonisins By Sharon Durham April 1, 2002Agricultural Research Servicepharmacologist 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. Story contacts Sharon A Durham Kenneth A Voss U.S. Department of Agriculture |