Aflatoxin M1 in UHT milk consumed in Turkey and first assessment of its bioaccessibility using an in vitro digestion model

Abstract

Contamination of milk and dairy products with aflatoxin M1 (AFM1) continues to receive increased attention because of its potential health hazard to humans. The first aim of this study was to know the occurrence and levels of AFM1 in whole UHT milk from main processors in Turkey in order to make a preliminary exposure assessment. A total of 40 milk samples were analysed for AFM1 using high performance liquid chromatography with fluorescence detection (HPLC-FD) after immunoaffinity column clean-up. Aflatoxin M1 was detected in 20% of samples at levels ranging from <0.004 to 0.076 μg l−1. Only two samples contained AFM1 above the EU limit of 0.05 μg l−1.The second aim of this study was to determine the bioaccessibility of AFM1 from milk using an in vitro digestion model. The bioaccessibility of AFM1 in spiked and naturally contaminated milk samples ranged from 80.5 to 83.8% and from 81.7 to 86.3%, respectively. No difference (P > 0.05) in AFM1 bioaccessibility was found between spiked and naturally contaminated milk samples. This study also assessed the binding of AFM1 by six probiotic bacteria under simulated gastrointestinal conditions. A 15.5–31.6% reduction in AFM1 bioaccessibility was observed in the presence of probiotic bacteria. Based on the results obtained in the present study, the mean daily intake of AFM1 through milk consumption was estimated as 0.008 ng kg−1 b.w. day−1 for Turkish adults.