Incidence of aflatoxin M-1 in Thai milk products

Two hundred seventy samples of raw milk and off-the-shelf milk products were examined for aflatoxin M-1 content using a radioimmunoassay. Aflatoxin M-1 was found in the majority of milk samples except 1 sample of raw milk and 11 samples of imported powdered milk. All cases of aflatoxin M-1 content greater than 0.5 ppb were found in 18% (48) of the samples including raw milk (17/67), pasteurized milk (20/63), ultra high temperature milk (7/60), sterilized milk (3/60), and pelleted milk (1/7). All powdered milk samples were negative for aflatoxin M-1 except two samples with less than 0.1 ppb. The positive aflatoxin M-1 test results for five of the raw milk samples were confirmed by HPLC.