| Mycotoxins are secondary metabolites produced by molds,including aflatoxins,ochratoxins,moniterpene toxins,zearalenone,umonsin etc,which may cause safety hazards in the growth,harvesting,storage and processing of crops,especially in feeds,due to the relatively poor storage environment.It is prone to produce mycotoxins,which are anti-nutritional factors that reduce feed potency and affect meat quality and even safety..In order to prevent and control the mycotoxin in corn during storage to increase the feed potency and reduce the influence of anti-nutritional factors,in this reaserch,we studied the extract of traditional Chinese herbal medicine Macleaya cordata intervened Aspergillus flavus on the toxicity-producing ability in maize.The specific research results are as follows:(1)A sensitive and simple UPLC-QQQ MS/MS method has been developed and validataed for the quantification of aflatoxin B1,deoxynivalenol,T-2 toxin,ochratoxin A,zearalenone and fumonisin B1.The analysis of six mycotoxins were separated on an Agilent ZORBAX Extend-C 18(2.1 mm×50 mm)column.The mobile phase was 0.1%formic acid in water and acetonitrile.The detection limit of aflatoxin B1 in maize is 0.1 μg/kg,the linear range is 0.1-100 μg/kg,r2≥0.9998.The detection limit of vomiting toxin is 20 μg/kg,the linear range is 50-5000 μg/kg,r2=0.9999.The detection limit of zearalenone was 2 μg/kg,the linear range was 5～500 μg/kg,r2=0.9997.The detection limit of ochratoxin A was 2 μg/kg,the linear range was 2～2000 μg/kg,r2≥0.9997.The detection limit of fumonisin B1 was 2 μg/kg,linear range 50～200 μg/kg,r2=0.9994.The detection limit of T-2 toxin is 10 μg/kg,linear range 20～500 μg/kg,r2=0.9989.The method also showed satisfactory results in terms of specificity,accurary and precisine,recoveries,matrix effect and stability.(2)Based on filter paper diffusion method and agar plate dilution method,the minimum inhibitory concentration of BE60 on Aspergillus flavus was determined to be 320 μg/mL.The growth and toxin metabolism of Aspergillus flavus in maize was treated with different concentrations of BE60.The metabolic accumulation of aflatoxin B1 in corn was analyzed by UPLC-QQQ MS/MS.The results showed that:1)BE60 diluted by 1.6 to 16 times according to the minimum inhibitory concentration(treatment 2,treatment 3 and treatment 4),which has obvious inhibitory effect on the growth of Aspergillus in corn,thereby preventing and controlling aflatoxin in corn.2)BE60 diluted about 32 times(treatment 1)according to the minimum inhibitory concentration,which has no inhibitory effect on the growth of Aspergillus flavus in corn,but has a certain inhibitory effect on the toxin metabolism of Aspergillus flavus in corn.(3)A qualitative analysis method based on UPLC-Q/TOF MS was established.According to the finding method of match the MS data of mycotoxin database,the compounds with matching degree of 90 was collected by MS/MS data acquisition.it was found that six compounds,Aflatoxin G1,Aflatoxin G2,Aflatoxin B1,Macrosine,5-methoxysterigmatostin and 3-O-Methysterigmatocystin had a 90-degree matching with MS/MS data in the database.Among them,Aflatoxin B1 was verified by the control retention time and the secondary MS fragments are consistent,indicating that the qualitative analysis results of this method are accurate and reliable.The treatment was carried out by diluting about 30 times of the minimum inhibitory concentration of BE60,and the Aflatoxin G1,Aflatoxin G2,Aflatoxin B1,Macrosporine,5-Methoxysterigmatocystin and 3-O-Methylsterigmatocystin were significantly decreased in the intervention group.Further explanation has a certain inhibitory effect on the metabolism of various toxins of Aspergillus flavus in corn. |
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