A monoclonal antibody (mAb)-based gold nanoparticle immunochromatographic assay (ICG) for zearalenone detection was developed, optimized, and validated. The detection limits of ICG optimized with appropriate amounts of zearalenone-bovine serum albumin and gold nanoparticle-mAb to zearalenone were 2.5 ng/mL and 30 μg/kg for the standard solution and spike sample, respectively, and a weak cross-reaction for α-zearalenol and β-zearalenol was observed. The assay required only 15 min to obtain results and one step to perform the assay. In validation, the results obtained from spiked corn (10, 20, 30, 50, and 100 μg/kg) and naturally contaminated corn samples by the ICG were in good agreement with those obtained by direct competitive enzyme-linked immunosorbent assay (DC-ELISA) and high-performance liquid chromatography (HPLC). Therefore, the results obtained in this study could be used as basic research for the development of zearalenone-ICG, and the ICG developed could be a useful on-site screening tool for the rapid detection of zearalenone in corn without special instrumentation.

This study conducted microbiological assessment in tunnel style strawberry greenhouses and packaging centers and suggested recommendations to establish a good agricultural practice for strawberry production. The samples from irrigation water, workers' gloves, harvest bins, soil, strawberry leaves and strawberries in greenhouses, packers' gloves, conveyor belts, packaging tables, and door knobs of entrances in packaging centers were collected. Bacterial cell counts of aerobic plate counts, coliforms, Escherichia coli, E. coli O157:H7, Salmonella, Staphylococcus aureus, and Bacillus cereus were then enumerated on appropriate selective media. In general, bacterial populations were similar (p ≥ 0.05) among strawberry greenhouses but not among packaging houses. E. coli and E. coli O157:H7 were negative in all samples, and low levels of Salmonella and B. cereus were detected. However, high bacterial cell counts of aerobic plate counts, coliforms, and S. aureus were found in most samples. These results suggest that food safety practice in strawberry greenhouses and packaging centers should be improved, and the results may be useful in the establishment of a good agricultural practice system for strawberry production.

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The objective of this study was to investigate the occurrence of aflatoxins in herbal medicines distributed in South Korea. A total of 700 herbal medicine samples (10 samples each for 70 types of herbal medicine) were analyzed by an enzyme-linked immunosorbent assay (ELISA) for aflatoxin B(1) (AFB(1)), and levels of total aflatoxins were quantified and confirmed by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). The levels of recovery of the methods were 84.30 to 102.68% (ELISA for AFB(1)) and 72.17 to 90.92% (LC-MS/MS for total aflatoxins). Fifty-eight (8.29%) of 700 samples were AFB(1) positive by ELISA, and 17 (2.43%) of them were finally confirmed as positive for total aflatoxins by LC-MS/MS. Total aflatoxin levels in the herbal medicines were from 4.51 to 108.42 μg/kg. Among the 17 samples, the AFB(1) content of 6 samples (11.95 to 73.27 μg/kg) and the total aflatoxin content of 10 (12.12 to 108.42 μg/kg) samples exceeded the legal limits set by the Korea Food and Drug Administration for AFB(1) (10 μg/kg) and by the European Commission for total aflatoxins (10 μg/kg), respectively. These results demonstrate the risk to consumers of herbal medicine contamination by aflatoxins and encourage further studies to investigate the transfer rate of mycotoxins to decoction, which is the final product for consumption.