Sensitive Enzyme-Linked Immunosorbent Assay for Screening Aflatoxin B1 in Food-And Feedstuffs

Aflatoxins are toxic metabolites produced by strains of Aspergillus flavus and Aspergillus parasiticus. They occur worldwide and contaminate certain foods and feedstufTs, especially wheat, corn, soya and groundnut products. Although the climate in Hungary is not favourable for production of these moulds, by consumption of imported foods these mycotoxins can cause serious health problems. As aflatoxin Bi is highly carcinogenic, its accepted level is regulated in many countries, the official limit in Hungary is 5 ng/g. Five years ago our institute started a research program for developing ELISA tests to detect mycotoxins in food and feeds, resulted in reagent-kits for T-2, zearalenone and ochratoxin-A. This program continued by development of sensitive, monoclonal antibody-based direct, competitive ELISA test and reagent kit for quantitative measurement of aflatoxin Bj with detection limit of 1.5 ng/g in cereals. The mean within-assay and interassay coefficients of variation of the standard curves were less than 10 %. With acetonitrile based extraction solvent the mean recovery values from cereals contaminated artificially with this mycotoxin was about 80 %. This test was offered for screening of samples in control laboratories.