Deoxynivalenol (DON) is a natural and ubiquitous toxic metabolite produced by filamentous fungi of the genus Fusarium. Approximately one quarter of the world's food crops (mainly cereals) are affected by mycotoxins such as DON. A rapid and non-destructive method to evaluate the quality and safety of grains is therefore required to eliminate these toxins from the food chain. The first portable acoustic device that predicts the concentration of DON in cereal grains has been developed using a broadband capacitive ultrasonic transducer. An acoustic method was optimised for the rapid prediction of DON in wheat. To measure the performance of this method, a model system comprising 0-100% scabby wheat grains was prepared and a single laboratory validation was carried out. The best regression model between DON concentrations determined by the reference ELISA method and the acoustic technique was obtained at an acoustic frequency of 32.2 kHz, with a correlation coefficient of 0.9852 and a repeatability coefficient of variation of 2.1-9.3%, which is much better than the results achieved by prototype acoustic spectrometers. These data show that acoustic technology allows the online monitoring of DON in cereal grains, such as wheat, because it is possible to analyse multilayer grain beds. Sound absorption depends on the grain size and moisture content, so it is advisable to use the equipment at the point of harvest, where one strain of cereals usually dominates and the grains have a more homogeneous morphology and uniform moisture content.

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In this panel discussion the following topics were discussed: SAMPLINGThe underestimation of analytical results due to sampling errors was found to have a strong influence on the consumer protection and/or industry liability because sampling errors are larger than analytical errors.It was stressed that the analyst should be aware of the sampling problems. These problems are different for various mycotoxins. However, it is possible to learn about the estimation of sampling errors from the approach which has already been used for the sampling of peanuts and corn-case.Sampling of large lots of agricultural products was found to be a basic area of research. Any research work in the area of sampling should therefore lead to good sampling procedures. A good sampling procedure can be characterised by taking enough samples (including retail samples) to allow later confirmation or further control of the sampling process by additional or further measurements after a certain time interval, providing sufficient information on the concept of distribution, demonstrating vigilance, and allowing the monitoring of the end-product.In addition, future sampling procedures need to recognize the fact that naturally contaminated feed is being used in industrial processes such as fermentation, detoxification (with clay, chemicals, etc.), and washing, etc., where highly contaminated materials are being produced and precautions for health care of workers have become extremely important. Sampling protocols need to be developed for contaminants (including mycotoxins) in heterogeneous materials such as patulin in apples, fumonisins in grains, and/or toxic plant components and are therefore important topics for future research activities. The demand of future sampling procedures for fumonisins should be focussed on matrices such as corn grits, flour, polenta, and extruded corn. The co-occurrence of zearalenone and fumonisins should also be taken into account when sampling procedures are developed for fumonisins in corn based products, because both mycotoxins are being produced by the same fungi. The heterogenous occurrence of moulds, sometimes present in "pockets" in bulk lots and the variability in mycotoxin production by moulds resulting in variable mycotoxin contents on individual kernels, forms a necessity to develop sampling procedures. The results obtained for aflatoxins might be a useful model in this case (see FNP 55 from FA0 sampling plans for aflatoxin analysis in peanuts and corn, ISSN 0254-4725). Regulatory activities in the area of sampling and analysis, such as the "code of practice" (for sampling) or a "convenant" (for analytical procedures) containing sampling procedures and analytical criteria are currently in force and/or drafted in The Netherlands to allow control measurements of industrially produced food and feed. This approach is compulsory to manufacturers and enables the controller to trace back the primary source of contaminated materials. ANALYSISThe following future research activities related to the analysis of myc...

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The present paper examines a technical paper of Whitaker and Dickens on aflatoxin testing plans that discusses (without a literature reference) a testing plan used In The Netherlands. However, this testing plan has never been in operation. We present the current situation In The Netherlands with respect to legislation and sampling plans on aflatoxin, which has fairly Important consequences for the results of the simulation study of Whitaker and Dickens. It Is shown that the percentage of rejected U.S.-exported lots In The Netherlands would Increase from 16% to 27% based on the actual testing plan In The Netherlands. The need for International harmonization of testing, and the role of Codex Allmentarlus is also emphasized