Investigation on the contamination of organic and conventional wheat flour in Shanghai City with seven kinds of mycotoxins

ObjectiveTo compare the levels of contamination of seven mycotoxins， including deoxynivalenol （DON）， zearalenone（ZEN）， fumonisin B1（FB1）， tenuazonic acid（TeA）， alternariol monomethvl ether（AME）， T-2 Toxin（T-2）， ochratoxin A（OTA） in organic and conventional wheat flour sold in Shanghai City， and analyze the cumulative contamination of Fusarium toxin， Alternaria toxin and OTA.MethodsSamples were extracted with acetonitrile， and the contents of the seven mycotoxins were detected using ultra-performance liquid chromatography-tandem mass spectrometry. The calibration curves for all mycotoxins were linear， with correlation coefficients above 0.99. The average recoveries of the spiked samples ranged from 80.13% to 122.86%， with relative standard deviations from 1.91% to 17.14%. This method is simple and rapid， with high accuracy and precision， and meets the requirements for mycotoxin analysis in flour.ResultsT-2 and FB1 were not detected in organic or conventional flours. The contamination levels of DON， ZEN， AME and OTA in organic flour were higher than those in conventional flour. The existence of at least two mycotoxins was observed in 97.5% of the flour samples， with DON+ZEN+OTA having the highest coexistence rate at 18.75%.ConclusionThe rate and level of mycotoxin contamination in organic wheat flour were higher than those in conventional wheat flour. The cumulative contamination of Fusarium toxins （DON， ZEN）， Alternaria toxins （TeA， AME） and OTA were also observed.