AFLATOXIN M-1 OCCURRENCE IN SAMPLES OF GRANA PADANO CHEESE

A total of 223 samples of Grana Padano cheese manufactured in 4 years (1991-94) by dairies in 11 provinces of the Po valley were checked for aflatoxin M-1. Grated cheese was extracted with chloroform and the de fatted extract was purified by an immunoaffinity column, aflatoxin M-1 was determined by HPLC using a fluorescence detector. From the analys is of the data it has emerged that only one sample exceeded the maximu m tolerated level in cheese in some European countries (250 ng/kg). Mo st samples (91%) were in the range 5-100 ng/kg and only 15 (6.7%) in t he range 100-250 ng/kg. Notwithstanding a diffuse microcontamination, the situation regarding the AFM(1) levels can be considered fairly sat isfactory. Mean contamination levels of 1992 and 1994 were significant ly higher (P < 0.05) than those of 1993 and 1991. No significant diffe rence was observed among provinces or dairies of origin.