Investigations on formation and occurrence of volatile nitrosamines in Danish cheese.

The formation and occurrence of volatile nitrosamines in Danish cheese has been studied. The investigations showed that nitrosamines are evenly distributed within a given cheese and between cheeses from the same lot. No influence of production factors, such as nitrate addition, composition and type of cheese, storage or packaging conditions, could be demonstrated. Seventy-six percent of 156 samples of commercially produced Danish cheeses contained no nitrosamines ((detection limit 0.1 micrograms/kg). Trace amounts (0.1-0.3 micrograms/kg) of nitrosamines were found in 22% of the samples and 2% contained 0.6-0.7 micrograms/kg. Forty-two percent of 19 cheeses imported to Denmark contained no nitrosamines. Trace amounts of nitrosamines were found in 37% of the samples and 21% contained 0.4-3.6 micrograms/kg. Cheese samples from retail shops had slightly higher contents of nitrosamines than samples taken at dairy plants.