Seasonal patterns of aflatoxin M1 contamination in commercial pasteurised milk from different areas in Thailand

Abstract

Aflatoxin M1(AFM1) levels were determined in pasteurised milk from five commercial trademarks produced in different areas in Thailand. One hundred and twenty milk samples were collected from local markets in Chiang Mai province, Thailand, to evaluate AFM1concentrations using immunoaffinity columns and high-performance liquid chromatography with fluorescence detection. The overall median AFM1level was 0.023 μg L-1ranging from 0.004 to 0.293 μg L-1. All trademarks had average AFM1concentrations lower than 0.05 μg L-1, with those in Trademarks 3 to 5 being higher than Trademarks 1 and 2 (P < 0.01). All trademarks had different seasonal patterns of AFM1, even though operating in the same area. However, only Trademark 3 showed significant differences of AFM1levels between seasons. The results suggested that farm management factors, rather than environment factors, were likely to be the main cause of AFM1contamination in dairy products. © 2012 Taylor and Francis Group, LLC.