Researchers Want Limits on Masked Mycotoxins in Grains

PARMA, ItalyGovernment limits on mold toxins that occur naturally in grain crops should be expanded to include so-called "masked mycotoxins" that change from harmless to potentially harmful forms in the body, according to a new study published in the journal Chemical Research in Toxicology.

Researchers at the department of food science at the University of Parma said molds growing naturally on wheat, corn and other plants produce toxic substances called mycotoxins, which some health experts regard as the most serious chronic dietary risk factorgreater than the potential health threats from pesticides and insecticides. Government regulations limit levels of mycotoxins that are permissible in food and animal feed. Plants protect themselves by binding or "conjugating" glucose, sulfur or other substances to the mycotoxin, producing conjugated mycotoxins that are not harmful.

The researchers said these "masked mycotoxins" are not included in current safety regulations because of uncertainty about what happens when people and animals eat them. The new study focused on two of the most widespread mycotoxin contaminants of grain cropsdeoxynivalenol (DON) and zearalenone (ZEN). Results showed, for the first time, that bacteria present in the large intestine in people deconjugate or "unmask" DON and ZEN, releasing the original toxic forms.

"For this reason, masked mycotoxins should be considered when evaluating population exposure," the study concluded.