Prevalence of aflatoxin B₁ contamination in pre- and post-harvest maize kernels, Food products, Poultry and livestock feeds in Tamil Nadu, India

Aflatoxins, a group of mycotoxins mainly produced by Aspergillus flavus and A. parasiticus, have adverse health effects on humans and livestock that ingest aflatoxin- contaminated food products and feeds. To secure the safety of food and feed, regular monitoring of aflatoxin levels is necessary. In order to understand the magnitude of aflatoxin contamination, a survey was conducted in different agro-ecological zones of Tamil Nadu, India and 242 samples consisting of pre- and post-harvest maize kernels, food products, poultry and livestock feeds were collected from farmers' fields, poultry farms, retail shops and supermarkets and analyzed for aflatoxin B₁ (AFB₁) contamination by enzyme- linked immunosorbent assay (ELISA) using antiserum raised against aflatoxin B₁-Bovine serum albumin (AFB₁-BSA). The results indicated that 61.3% of the maize kernel samples were contaminated with AFB₁ and the levels of AFB₁ in 26% of the pre- and post-harvest maize kernels exceeded 20 μg/kg. The highest level of AFB₁ (245 μg/kg) was recorded in post-harvest maize kernel samples. In food products AFB₁ was detected only in two samples out of 30 samples tested. Furthermore, the levels ranged from 0.6 to 3.7 μg/kg. In poultry feeds, AFB₁ was detected in 30 out of 53 samples and the levels ranged from 0.7 to 31.6 μg/kg. Among the 40 livestock feed samples evaluated 29 samples were contaminated with AFB₁ at level ranging from 1.8 to 244.9 μg/kg.