Submitted to: Journal of Association of Official Analytical Chemists International
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/29/2003
Publication Date: 11/15/2003
Citation: Whitaker, T.B., Richard, J.L., Giesbrecht, F.G., Slate, A.B., Ruiz, N. 2003. Estimating deoxynivalenol in shelled corn barge lots by measuring deoxynivalenol in corn screenings. Journal of Association of Official Analytical Chemists International 86:1187-1192. Interpretive Summary: Deoxynivalenol (DON) is a naturally occurring toxic compound produced by fungi and found on many types of grain. The FDA has established a maximum limit for DON levels in consumer foods and animal feeds. The U.S. Department of Agriculture and grain industry attempt to detect and remove grain contaminated with DON from food and feed markets when levels of DON are greater than the FDA limit. The grain industry is interested in finding methods to improve the accuracy and precision of DON sampling plans used to inspect grains for DON. Other toxic compounds are more likely to be found in the poor quality segments of agricultural commodities. To determine if DON is more concentrated in small, poor quality particles of corn, samples of shelled corn were taken from commercial lots contaminated with DON and divided into small and large corn particles using official USDA screens. DON was measured in both the large and the small corn particles to determine if DON was concentrated in the small, poor quality particles. Results showed that, on the average, there was 2.8 times more DON in the small particles than in the larger particles of corn. As a result, more effective sampling plans can be designed to estimate DON in bulk lots by measuring DON in the small or poor quality corn particles.
Technical Abstract: To determine if deoxynivalenol (DON) is concentrated in small or fine corn particles screened from corn lots, 14 to 23 test samples weighing 1.1 kg were taken from each of 10 barges of shelled corn. Each of the 181 test samples was divided into two components (fines and clean) using a 5 mm screen. The clean component sample rode the 5 mm screen and the fines component sample passed through the 5 mm screen. The deoxynivalenol (DON) concentration in fines component samples was about 3 times the DON concentration in the clean component samples. The DON in the 181 fines and clean component samples averaged 689.0 and 206.1 ng/g, respectively. Regression equations were developed to predict the DON in the barge based upon measurements of DON in the fines component sample. The ratio of DON in the lot to DON in the fines component sample was 0.359. The coefficient of variation (CV) associated with predicting the DON concentration in a lot with 359 ng/g using a 1.1-kg test sample was 47.0%. Increasing sample size to 4.4 kg reduced the CV to 23%.