SCIENCE & TECHNOLOGY
WINE’S MYCOTOXIN PROFILE GROWS Another FUNGAL TOXIN associated with grains is present in wines worldwide
ELIZABETH K. WILSON, C&EN WEST COAST NEWS BUREAU
AS THEY RAISE a glass, most wine drink-
ers would prefer to ponder the ancient beverage’s possible health benefits—lowering cholesterol, improving heart health— rather than its possible contamination with carcinogenic, kidney-destroying fungal toxins. But dangerous mycotoxins produced by fungus species are found in wine. Mycotoxins are longtime contaminants as old as food itself. Multitudes of toxinproducing fungi invade grains, peanuts, coffee, grapes, and other foods. Wine, by association with grapes, is not immune: It can contain small amounts of
In the past year, several groups around the world, including Nielsen’s, have detected fumonisins in grapes, raisins, and must. It was then a short leap from grapes to wine. Because wine contains a plethora of potentially confounding compounds, such as tannins and anthocyanins, Nielsen’s group developed a cation-exchange method to purify samples before subjecting them to chromatographic and mass spectrometric studies. They put to the test 77 different wines from all over the world, including red and white varieties and vintages ranging from 1991 to 2008. Eighteen of the wines contained some fumonisin B2, some with only
aflatoxins, which are carcinogens most notoriously associated with peanuts, and ochratoxin A, found in decaying fruits. Allowable amounts of these toxins in foods are heavily regulated by the U.S. and European governments. OH Now, chemists have discovered O that yet another mycotoxin, known as fumonisin B2, once thought to HO be mainly a problem in grains, also O O exists in wine (J. Agric. Food. Chem., OH OH O DOI: 10.1021/jf904520t). Kristian F. Nielsen, who heads the analytical facilities lab at the Center for MicroNH2 O bial Biotechnology at the Technical University of Denmark, and his colleagues Thomas O. Larsen and Jesper O M. Mogensen used an augmented OH analytical technique to discover that HO 23% of 77 wines they tested contain Fumonisin B2 fumonisin B2. Before you throw out your bottles of Châteauneuf du Pape, consider that as 1 µg/L. Sorry, Californians: The wine with with many foods, levels of these toxins are the highest level of fumonisin B2 was a 1998 quite low, well below government stanCalifornia Zinfandel, with 25 µg/L. But the dards set in most countries. But the new group found no correlation with year, variwork suggests a need for further study of ety, or location. fumonisins in wine, the researchers say. Chris M. Maragos, who studies fumonisins at the U.S. Department of Agriculture’s THE FAMILY of fumonisins, which are Agricultural Research Service in Peoria, Ill., toxic to the liver and kidneys in animals, notes that “the highest level found in the were discovered in the late 1980s. They’re wine (25 µg of fumonisin B2 per liter) is still produced by Fusarium molds, which thrive only about 1% of the guidance level for fuon grain products. Since their discovery, monisins in maize.” The guidance level in the U.S. Food & Drug Administration and maize was reached with significant scienthe European Economic Community have tific input, as well as with public comment, set limits for concentrations in foods. he adds, “so it does represent a reasonable “Until 2007, we did not think that any value given what we know about the toxicfungi growing on grapes could produce ity and prevalence of the fumonisins.” fumonisins,” Nielsen says. “Thus there was The effect of the discovery on the wine no reason to search for them.” But only industry and the response of regulatory three years ago, scientists discovered that a agencies are yet to be determined. Norma non-Fusarium fruit-loving fungus, AspergilR. Hill, chief of the Tobacco Tax & Trade lis niger, can also produce fumonisins B2, Bureau’s Compliance Monitoring LaboraB4, and B8 (J. Agric. Food. Chem. 2007, 55, tory, in Walnut Creek, Calif., whose group 9727). Because this fungus preys on fruit, has studied mycotoxins in alcoholic beverscientists began looking for traces of fumoages, declined to comment on the issue as nisins in crops such as grapes. this article was going to press. ■ O
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DRINK UP Scientists find that wine, which is already known to contain small amounts of mold toxins, contains yet another.
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