A Rapid ScreeningMethod for the Tremorgenic Indole-Diterpene Alkaloid Mycotoxin Paxilline in Beer.

The tremorgenic paxilline (PAX), an indolediterpene alkaloid mycotoxin, was recently detected as a natural contaminant of ergot of barley and rye. To check the possibility of a transfer of this mycotoxin into beer, a rapid and sensitive immunochemical method for the analysis of PAX in commercial bottled beer was developed. A straightforward sample preparation procedure could be established, including degassing, pH adjustment, optional filtering, and finally a 1:5 dilution with a methanolic phosphate-buffered saline solution. Analysis of PAX was performed by a competitive indirect enzyme immunoassay (EIA). The detection limit at a cut-off value of 80% B/B0 of the EIA standard curve was evaluated by analysis of spiked beer. PAX at levels of 3 μg/L and 5 μg/L yielded 69% and 100% positive results, therefore the detection limit in beer was at 5 μg/L. Recoveries of PAX at levels of 5-20 μg/L were 88-97%, coefficients of variation were 17-22%.With these characteristics, the EIAwas considered to be a suitable screening method for PAX in beer. A survey of bottled beer from the German market was conducted which included 38 samples of domestic and international brands, the latter containing various flavoring ingredients. [ABSTRACT FROM AUTHOR]