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United States Department of Agriculture

Agricultural Research Service


item Whitaker, Thomas

Submitted to: Journal of Food Additives & Contaminants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 20, 2005
Publication Date: December 10, 2005
Citation: Whitaker, T.B. 2005. Sampling foods for mycotoxins. Journal of Food Additives & Contaminants.

Interpretive Summary: Mycotoxins are carcinogenic and toxic compounds, produced by molds, which can contaminate various agricultural commodities such as corn and peanuts. The Food and Drug Administration set limits for several mycotoxins in the food supply. A mycotoxin in a food shipment is estimated by measure the mycotoxin in samples taken from the shipment. Because there is variability associated with each step of the procedure to measure a mycotoxin in a lot, the true mycotoxin concentration in the lot cannot be determined with 100 percent certainty. If the sample concentration does not accurately reflect the lot concentration, then the lot may be misclassified and there may be undesirable economic risks for the food industry and undesirable health risks for the consumer. Methods to reduce sampling, sample preparation, and analytical variability are demonstrated. Techniques that can be used to design sampling plans to minimize the misclassification of lots and reduce the undesirable consequences associated with regulatory decisions about the fate of bulk lots are described. Using these techniques to design mycotoxin-sampling plans will reduce health risks for the consumer and reduce economic losses for the food manufacturer.

Technical Abstract: It is difficult to obtain precise and accurate estimates of the true mycotoxin concentration of a bulk lot when using a mycotoxin-sampling plan that measures the concentration in a small portion of the bulk lot. A mycotoxin-sampling plan is defined by a mycotoxin test procedure and a defined accept/reject limit. A mycotoxin test procedure is a complicated process and generally consists of several steps: (a) a sample of a given size is taken from the lot, (b) the sample is ground (comminuted) in a mill to reduce particle size, (c) a subsample is removed from the comminuted sample, and (d) the mycotoxin is extracted from the comminuted subsample and quantified. Even when using accepted test procedures, there is uncertainty associated with each step of the mycotoxin test procedure. Because of this variability, the true mycotoxin concentration in the lot cannot be determined with 100 percent certainty by measuring the mycotoxin concentration in a sample taken from the lot. The variability for each step of the mycotoxin test procedure, as measured by the variance statistic, is shown to increase with mycotoxin concentration. Sampling is usually the largest source of variability associated with the mycotoxin test procedure. Sampling variability is large because a small percentage of kernels are contaminated and the level of contamination on a single seed can be very large. Methods to reduce sampling, sample preparation, and analytical variability are discussed.

Last Modified: 11/25/2014
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