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United States Department of Agriculture

Agricultural Research Service

Title: Testing Shelled Corn for Aflatoxin. Part Iii: Evaluating the Performance of Aflatoxin Sampling Plans

Authors
item Johansson, Anders
item Whitaker, Thomas
item Giesbrecht, Francis - NC STATE UNIVERSITY
item Hagler, Jr, Winston - NC STATE UNIVERSITY
item Young, James - NC STATE UNIVERSITY

Submitted to: Journal of Association of Official Analytical Chemists International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 9, 2000
Publication Date: December 1, 2000
Citation: JOHANSSON, A.S., WHITAKER, T.B., GIESBRECHT, F.G., HAGLER, JR, W.M., YOUNG, J.H. TESTING SHELLED CORN FOR AFLATOXIN. PART III: EVALUATING THE PERFORMANCE OF AFLATOXIN SAMPLING PLANS. JOURNAL OF ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTS INTERNATIONAL. 2000. v. 83. p. 1279-1284.

Interpretive Summary: Aflatoxin is a carcinogenic and toxic compound produced by molds found in several grain products. The Food and Drug Administration has established a legal limit that controls the maximum quantity of aflatoxin allowed in grain destined for food and feed products. As a result, grain products are inspected by processors, manufacturers, USDA, and FDA to detect and remove contaminated lots from the food and feed chain. Because of the random errors associated with the aflatoxin test procedure, it is difficult to determine the true aflatoxin content of a large bulk shipment or lot. As a result, it is difficult to accurately classify lots according to their aflatoxin content. Some good lots will test bad (processor's risk) and some bad lots will test good (consumer's risk). Knowing the variability and distributional characteristic associated with testing shelled corn for aflatoxin, a method has been developed to predict the effects of a sampling gplan design on the magnitude of the processor's and consumer's risk. The method to predict the processor's and consumer's risks can also be used to design the most cost-effective sampling plans that minimize both risks. The evaluation method will help the grain industry and regulatory agencies develop sampling plans to reduce economic losses to the grain industry and health risks to the consumer.

Technical Abstract: Evaluating the effects of several sample sizes and sample acceptance levels on the performance of aflatoxin sampling plans for shelled corn are discussed in this study. Six sampling plans were evaluated for a range of sample sizes and sample acceptance levels. For a given sample size, decreasing the sample acceptance level: (a) decreases the percentage of lots accepted while increasing the percentage of lots rejected at all aflatoxin concentrations; and (b) decreases the average aflatoxin concentration in the lots accepted and lots rejected. For a given sample size where the sample acceptance level decreases relative to the regulatory guideline, the number of false positives increases and the number of false negatives decreases. For a given sample size where the sample acceptance level increases relative to the regulatory guideline, the number of false positives decreases and the number of false negatives increases. For a given sample acceptance level, increasing the sample size: (a) increases the percentage of lots accepted at concentrations below the regulatory guideline while increasing the percentage of lots rejected at concentrations above the regulatory guideline; and (b) decreases the average aflatoxin concentration in the lots accepted while increasing the average aflatoxin concentration in the rejected lots. For a given sample acceptance level that equals the regulatory guideline, increasing the sample size decreases misclassification of lots (both false positives and false negatives).

Last Modified: 11/25/2014
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