A six year survey (1999-2004) of the ocurrence of aflatoxin M1 in daily products produced in Portugal.

Aflatoxin M1, a mutagenic and carcinogenic metabolite of aflatoxin B1, occurs in milk from animals fed on food contaminated with some species ofAspergillus. Aiming to investigate the occurrence of AFM in dairy products produced in Portugal. 598 samples of raw milk were analysed during six years (1999-2004). 25 samples of powder milk and 42 traditional fresh cheeses were also analysed. The toxin was extracted using an immunoaffinity column method and quantified by HPLC. AFM1 was detected in 394 (65.8%) of the raw milk samples. Along the analysed period AFM: was detected at a low level (0.005-0.05μg/l) in 54.8% of the samples and at a level ranging from 0.041-0.05 in 2.8% of the samples. From 2001 to 2004, 49 samples (8.2%) were contaminated with levels above the maximum permitted level (>0.051 to 0.08). None of the samples of powder milk and traditional fresh cheese revealed to be contaminated with AFM1.