[Survey on fungi contamination and natural occurrence of mycotoxins in 94 corn feed ingredients collected from China].

Objective: To investigate fungi contamination and the natural occurrence of mycotoxins in corn feed ingredients collected from China. Methods: A total of 94 corn feed ingredient samples were collected from 8 Chinese provinces(i.e., Anhui, Hebei, Heilongjiang, Jilin, Jiangsu, Liaoning, Inner Mongolia, and Shandong)in February 2014. A tandem ultra-performance liquid chromatographymass spectrometry method was used for simultaneous detection of twelve kinds of mycotoxins, including aflatoxin(AF), type A and type B tricothecenes, and zearalenone(ZEN). Contaminated fungi were also identified and counted. Results: AF was detected in 36.2%(34/94)of samples; the concentration of AFB1 was the highest in the four AFs with the range: 0.3~181.3 µg/kg; and then followed by AFB2(range: 1.0-74.3 µg/kg). There were 7 samples(7.5%)with AFB1 concentrations higher than the tolerance limit of 50 µg/kg. The concentration of type A tricothecenes in all samples was lower(0.1-10.5 µg/kg). DON had the most serious contamination than other kind of type B tricothecenes(range: 0.7-606.6 µg/kg; median: 66.3 µg/kg). The DON concentration in all samples was below the tolerance limit of 1 000 µg/kg. ZEN was detected in 76.6%(72/ 94)of samples(median: 36.9 µg/kg), with 3 samples having ZEN concentrations higher than the tolerance limit of 500 µg/kg. The survey on fungi contamination showed that all samples were contaminated by fungi(range: 5.0-1.4×105 CFU/g). There were 18 and 3 samples with quantities of fungi higher than the tolerance and forbidden limits, respectively. The Aspergillus, Penicillium, Fusarium, Trichoderma and Mucor genuses were the predominant fungi in corn feed ingredients, with detection rates of 71.3%(67), 60.6%(57), 71.3%(67), 27.7%(26), and 24.5%(23), respectively. The detection rate of Fusarium moniliforme, 73.4%(69/94)was higher than that of Aspergillus flavus, 41.5%(39/94). Conclusion: In this survey, the corn feed ingredients were not seriously contaminated by AF and type A tricothecenes but mainly contaminated by type B trichothecenes, including DON and its derivatives, as well as ZEN. They were also contaminated by fungi such as Aspergillus, Penicillium, and Fusarium.