Afloxin M, in Pasteurized and Ultrapasteurized Milk with Different Fat Content in Mexico.

High per capita milk consumption in Mexico indicated a strong need for documentation of aflatoxin M[sub 1] (AFM[sub 1]) levels in milk. A survey of 580, 2-liter samples (n = 290), was conducted to quantify AFM[sub 1] using high-performance liquid chromatography, considering two maximum tolerance levels (0.05 and 0.5 µg/liter). We relate aflatoxin levels in the seven most consumed brands from different regions, with two processes (pasteurized and ultrapasteurized), different expiration dates, and different fat content: whole fat (28, 30, and 33 g), half-skimmed (10, 16, and 20 g), light (1, 2, and 4 g), and with vegetable oil. Pasteurization and ultrapasteurization did not diminish AFM[sub 1] contamination present at levels of 0 to 8.35 µg/liter in 40% of the milk samples at concentrations ≥0.05 µg/liter and in 10% of the samples at ≥0.5 µg/liter. Statistically significant relationships were AFM[sub 1] contamination with brand (P = 0.002 at the ≥0.05 µg/liter level and P = 0.034 at the ≥0.5 µg/ liter level) and higher AFM[sub 1] levels with mild or warm seasons of the year (P = 0.0003). Samples with greater fat content had slightly more probability (P = 0.067) of being contaminated by AFM[sub 1] at the ≥0.5 µg/liter level. The milk with the lowest contamination of AFM[sub 1] was a brand imported as powder and rehydrated in Mexico. [ABSTRACT FROM AUTHOR]