Abstract:Objective To investigate the natural occurrence of hexadepsipeptides mycotoxins, including beauvercin (BEA), enniatins (ENNs)of enniatin A (ENA), enniatin A1 (ENA1), enniatin B (ENB), and enniatin B1 (ENB1) in corn and corn-based samples collected from Shandong Province in 2017. Methods One hundred and fifty-eight corn and corn-based samples were collected from the east, west, south, and central district of Shandong in 2017. The samples were extracted with acetonitrile-water(85∶15, V/V), cleaned up with solid phase extraction column, followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) detection of the concentrations of 5 mycotoxins. Results BEA was the predominant mycotoxin in 158 samples, and the positive rate and the average level of BEA were 82.3% (130/158) and 65.26 μg/kg. The positive rates and the average levels of 4 ENNs were 55.1% (87/158) and 0.28 μg/kg for ENA, 8.2% (13/158) and 0.62 μg/kg for ENA1,3.8% (6/158) and 1.19 μg/kg for ENB, 56.3% (89/158) and 0.13 μg/kg for ENB1. The average levels of the 5 mycotoxins in corn kernels, corn flour and corn flakes were 46.96,6.45 and 0.17 μg/kg for BEA, 0.13,0.35 and 0.06 μg/kg for ENA, 0.14,0.76 and 0.00 μg/kg for ENA1,0.23,2.15 and 0.00 μg/kg for ENB, 0.21,0.15 and 0.08 μg/kg for ENB1. BEA was the most predominant mycotoxin in samples collected from east district, and the positive rate and the average level for those samples were 87.0% (87/100) and 95.75 μg/kg. The positive rates of 4 ENNs in the east, west and central districts were lower than those of BEA, but not for the positive rates of ENA and ENB1 in south (both of 91.3%, 21/23). The average levels of 4 ENNs in the 4 districts were lower than BEA. Conclusion Corn and corn-based products collected from Shandong were contaminated by 5 hexadepsipeptides mycotoxins, especially for BEA, and there were mycotoxin kinds and geographic distribution differences for mycotoxin contamination. It wa necessary to conduct a wide range of monitoring especially for BEA in corn and corn-based samples collected from eastern seaboard of Shandong.
