Aflatoxins, deoxynivalenol and zearalenone in maize straw harvested in Tepatitlan, Jalisco

Abstract

There are few reports on the contamination of total aflatoxins (AFs), AFB1, deoxynivalenol (DON) and zearelenone (ZEA) in maize straw harvested in Mexico; hence, the aim of this study was to determine the concentration of such mycotoxins by immunoassay analytical technique (ELISA) and High-performance liquid chromatography (HPLC) in straw coming from 17 genotypes of white and yellow maize cultivated during 2009 in the municipality of Tepatitlan, Jalisco. Results showed a high percentage of occurrence of total aflatoxins by ELISA (88.2 %) and AFB1 by HPLC (84 %) with average levels of 7.0 ± 3.29 mg Kg-1 and 3.68 ± 2.91 mg Kg-1 respectively; DON determination by ELISA method presented 100 % of positive samples, average concentration was 6.04 ± 3.49 mg Kg-1; regarding the determination of ZEA by ELISA, 98.5 % of positive samples was observed with average levels of 1164.6 ± 1046.7 mg Kg-1 and by HPLC 81 % presented average levels of 544.6 ± 1035 mg Kg-1, no statistical difference was observed among straw of the different genotypes of maize (p>0.05) in any of the analyzed mycotoxins. It is important to mention that none of the samples exceeded the highest level recommended by the Mexican legislation for aflatoxins in feed for animals (20 mg Kg-1), however, 23.5 % (16/68) of the determined samples by HPLC surpassed the limit allowed for AFB1 by the European Community (5 mg Kg-1); 4.4 % (3/68) surpassed the levels allowed by DON (12 mg Kg-1); while ZEA showed 11.8 % (8/68) of samples detected for ELISA and 10.3 % (7/68) by HPLC with levels that exceed those recommended by the European Commission (2000 mg Kg-1), there is no regulation in Mexico for these mycotoxins.