Modified grain sorter spots mycotoxins

Agricultural Research, June, 2004 by Tom C. Pearson, Donald T. Wicklow

Many outside plants can be infested with fungi that produce potentially harmful compounds called mycotoxins. In favorable conditions, these fungi can infect crops such as corn, cottonseed, wheat, or peanuts, producing toxins that can cause serious illness in livestock and may be carcinogenic to humans. But detecting the fungi on large-volume crops like grain--and removing them--is a big challenge to commodity handlers.

Now an engineer has used near-infrared spectroscopy to transform a standard grain sorter into a fast, effective tool for detecting two important mycotoxins that occur in corn: aflatoxin, produced by some strains of Aspergillus flavus, and fumonisin, produced by Fusarium fungi. He added a pair of filters that correspond to two bands of infrared light needed to detect aflatoxin and fumonisin.

One pass through this modified sorter detected and removed 80 percent or more of corn infected with the two mycotoxins. And the sorter mistakenly rejected only 5 percent of uncontaminated corn instead of upwards of 10 percent. Tom C. Pearson, USDA-ARS Grain Marketing and Production Research Center, Manhattan, Kansas; phone (785) 776-2729, e-mail tpearson@gmprc.ksu.edu. Donald T. Wicklow, USDA-ARS Mycotoxin Research Unit, Peoria, Illinois; phone (309) 681-6243, e-mail wicklodt@ncaur.usda.gov.