Detection and occurrence of cyclopiazonic acid in cheeses

Techniques for detection of cyclopiazonic acid in P. camemberti fermented cheeses are described. They include extraction with CHCl3-MeOH, purification, analysis and quantitation by thin-layer chromatography, and confirmation procedures. Recovery from spiked samples was 75-85%, and the lowest detectable level was 0.02 ppm. This toxic metabolite of P. camemberti was found in the crust of 11 of 20 cheeses of different brands, but not in the inner part. The highest levels were found in three samples: 0.4, 1, and 1.5 ppm. Cyclopiazonic acid doses eventually ingested by a consumer appear to be very low: 3 or 4 micrograms in a portion of the most contaminated sample.