Trace amounts of nitrosamines in powdered milk and milk proteins



No nitrosamines could be detected above a level of 1 μg kg−1 in five samples of indirectly dried skim-milk powders, 20 samples of directly-fired skim-milk powders and 10 samples of directly-fired butter-milk powders, selected at random from eight processing plants in New Zealand over a period of 8 months continuous production. The maximum level of N-nitrosodimethylamine (NDMA) observed in samples of milk proteins (lactic casein and lactalbumin) was 0.3 μg kg−1 (in one sample) while most of a further 10 samples showed traces of NDMA at the limit of detection of 0.1 μg kg−1.