Occurrence of aflatoxin M 1 in commercial powdered milk in Bangkok, Thailand

Abstract

The contamination of milk with aflatoxin M 1 (AFM 1), a possible carcino-gen to humans, is a serious problem. In Thailand, there are few reports on AFM 1 contamination in powdered milk. In this study, we investigated the occurrence of AFM 1 in 79 commercial powdered milk products in Bangkok, Thailand over five years (2010–2014). An in-house immunoaffinity column-HPLC (IAC-HPLC) method was developed. Reconstituted powdered milk (10 mL) was applied to our IAC. The recoveries from 0.005–0.15 ng/mL AFM 1 -spiked reconstituted milk were 73.6–86.3% with 5.2–7.4% of RSD. Twelve samples (15%) were contaminated with 0.005–0.135 ng/mL of AFM 1 (aver-age 0.024 ng/mL, overall average 0.004 ng/mL) in reconstituted powdered milk. Our data indicated that the risk of AFM 1 in commercial powdered milk in Bangkok, Thailand was sufficiently low. Aflatoxins, classified as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer (IARC), are produced principally by the fungi Aspergillus flavus and A. parasiticus, which infect food