|Kim, Eun Kyung|
Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/22/2003
Publication Date: 4/12/2004
Citation: Maragos, C.M., Kim, E. 2004. Detection of zearalenone and related metabolites by fluorescence polarization immunoassay. Journal of Food Protection. 67(5):1039-1043. Interpretive Summary: Fusarium graminearum is a fungus that causes ear rot in maize and produces toxic metabolites (mycotoxins). One such mycotoxin is zearalenone, which has estrogenic activity and contaminated feed can cause illness in livestock, particularly swine. Testing of commodities for zearalenone is currently done with enzyme-linked immunosorbent assays (ELISAs) or expensive chromatographic methods. This report describes the development of a rapid fluorescence polarization immunoassay for measuring zearalenone in maize. This fast, easy to use, and low cost assay provides an additional tool for the rapid screening of maize for zearalenone and will benefit those who test for this mycotoxin.
Technical Abstract: Zearalenone is an estrogenic mycotoxin commonly found in grains throughout the world. A number of instrumental and antibody-based methods including enzyme-linked immunosorbent assays (ELISAs) have been developed to detect zearalenone (ZEN) and related toxins in commodities and foods. While convenient, the commercial ELISAs for small molecules such as ZEN require a washing step to separate bound and unbound enzyme label before detection. Fluorescence polarization (FP) immunoassays have an advantage in that separation of bound and unbound label is not required, a property that is useful for improving the speed of the assays. We report the development of an FP immunoassay for ZEN in maize. When combined with a rapid extraction technique, the assay could be used to detect as little as 0.11 microgram ZEN/g maize within 10 min. The assay showed cross-reactivity to the ZEN analogs zearalanone, alpha-zearalanol, alpha-zearalenol, beta-zearalenol, and beta-zearalanol to the extent of 195%, 139%, 102%, 71%, and 20%, relative to ZEN (100%), respectively. Recovery of ZEN from spiked maize over the range of 0.5 to 5 microgram/g averaged 100.2% (n=12). The FP immunoassay compared favorably to a liquid chromatographic method for the analysis of 60 naturally contaminated maize samples and maize samples amended with culture material. The results suggest the FP immunoassay provides a rapid method for screening of maize for ZEN.