Detection of aflatoxin B1 contamination in foods and feeds by enzyme-linked immunosorbent assay

Aflatoxin B1 (AFB1) was conjugated to keyhole limpet hemocyanin (KLH) and polyclonal antibodies were raised against AFB1-KLH in a New Zealand White inbred rabbit. By using the developed antibody, a sandwich ELISA method was standardized for quantifying AFB1 in foods and feeds. The developed polyclonal antibodies were highly sensitive and could detect AFB1 at a dilution of 1:10,000 and the detection limit of AFB1 was 10 ppb. In order to understand the magnitude of AFB1 contamination, a total of 68 samples consisting of maize-based foods and poultry feed samples collected from retail shops, supermarkets, poultry farms and poultry feed dealers of Tamil Nadu, India were analyzed for AFB1 contamination by ELISA. AFB1 contamination in maize based food products was detected in nine samples out of 17 samples tested. However, only one sample exceeded the tolerance level of 20 ìg/kg. AFB1 contamination in feeds was observed in more than 88 % of the samples tested and its level ranged from 5.4 to 125.4 μg/kg and 31 samples out of 51 samples tested contained AFB1 above 20 μg/kg.