Occurrence of aflatoxin M1 in some samples of UHT, raw & pasteurized milk from Indian states of Karnataka and Tamilnadu

Aflatoxin M1 (AFM1) is a toxic metabolite found in the milk of lactating animals which have consumed feedstuffs contaminated with aflatoxin B1. Ultra high temperature treated (UHT) milk is a product which is becoming popular in developing countries like India as there is a lack of proper cold storage or refrigeration facilities. In this study, 45 samples of UHT milk of popular brands prevalent in the market were analyzed for the presence of AFM1 by reversed phase HPLC using fluorescent detector after cleanup of sample with immunoaffinity columns. All samples of plain UHT milk were positive for AFM1 and 38% of these contained levels more than 0.5 μg/kg, the maximum permitted limit prescribed by the Codex Alimentarius Commission and by the mandatory regulations of the country, the FSSAI Regulations, 2011. In 62.5% of flavored UHT milk, AFM1 was below detectable levels (0.02 μg L−1). However, 12.5% of these samples also contained levels exceeding the maximum permitted limits. AFM1 was present in 61.6% of the 52 raw milk samples analyzed from the two states of Karnataka and Tamilnadu with a range of 0.1-3.8 μg L−1. 17.3% of these samples also exceeded the regulatory limits of the country.

► UHT milk is shelf stable and the demand for it is growing in the country. ► 38% of plain UHT milk exceeded the maximum permitted limits of Codex regulations. ► AFM1 in 62.5% of flavored UHT milk was below detectable levels (0.02 μg L−1). ► 17.3% of the raw milk samples from the two states of India exceeded 0.5 μg kg−1.