The occurrence of volatile and non-volatile N‐nitrosamines in cured meat products from the Danish market

Several epidemiological studies emphasize the consumption of processed meat products as a risk factor of colorectal cancer, linking N-nitrosamines (NAs) formed during nitrite curing to this cancer risk. The occurrence of volatile N-nitrosamines (VNAs) has over the years been intensively studied while the knowledge on the occurrence and toxicity of non-volatile N-nitrosamines (NVNAs) is still limited. Therefore, this study focuses on quantification of both VNAs and NVNAs in a large selection of processed meat products. For this purpose, a robust, specific and sensitive method allowing analysis of seven VNAs and two NVNAs was optimized and validated using kassler, sausage, and salami. The limit of quantification achieved was 0.1 - 0.5 ng·g^-1 for most of the VNA, and 2.3 - 4.2 ng·g^-1 for the NVNA. In one hundred commercial samples N-nitroso-thiazolidine-4-carboxylic acid (NTCA) was the most frequently detected (97 samples) among all target NAs and it was found at concentrations ranging from 3.1 ng·g^-1 to 1660 ng·g^-1. The samples contained relatively low mean levels of the individual VNAs (≤1 ng·g^-1). The levels of N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), and N-nitrosopiperidine (NPIP) ranged from non-detectable to 3.8, 10.8 and 2.9 ng·g^-1, respectively. A correlation between the detected residual levels of nitrite and/or nitrate and concentrations of individual NAs could not be demonstrated. Based on principle component analysis (PCA) some correlations between salami, sausage and bacon and NAs could be shown.