Methods and method evaluation for mycotoxins.

Mycotoxins are metabolites of molds frequently found on and in agricultural commodities, food and feeds. Owing to their demonstrated acute, sub-acute and, in some cases, chronic toxicity, an effort has been made, worldwide, to control human and animal exposure to these toxic chemicals. This effort depends upon the availability of validated analytical methods for their detection and quantitation. This paper outlines the methodology available, and the procedures used to validate, i.e. evaluate, these methods based on the use of interlaboratory collaborative studies and the application of the HORRAT.

Ochratoxins A and B, Xanthomegnin, Viomellein and Vioxanthin Production by Isolates of Aspergillus ochraceus from Green Coffee Beans.

Isolates from Aspergillus ochraceus obtained from green coffee beans were cultured on rice and water. After 20 d of growth the cultures were extracted with chloroform and the extracts were analyzed by high performance liquid chromatography for ochratoxin A (OA), ochratoxin B (OB), xanthomegnin (X), viomellein (V) and vioxanthin (VX). Forty-three percent of the isolates produced OA at an average level of 397 µg of toxin/g rice, 17% produced OB at an average level of 312 µg/g, and 84% produced X, V, and VX at an average level of 281, 417 and 386 µg/g, respectively. The highest levels of toxin production were OA, 2088 µg/g; OB, 3375 µg/g; X, 1562 µg/g; V, 2514 µg/g; and VX, 2054 µg/g. VX has not previously been reported as an A. ochraceus metabolite.