Effect of freezing and cooking on sodium nitrite content in processed meat products

Sodium nitrite (NaNO2) is a bacteriostatic preservative widely used in the meat industry. However, as a food additive it can have a harmful effect on human health, for example by contributing to methaemoglobinaemia and anaemia, and may also be a precursor of mutagenic, teratogenic and carcinogenic N-nitrosamines. The aim of the study was to evaluate the effect of freezing and cooking on NaNO2 content in selected processed meats. A research hypothesis was verified that freezing and cooking have an impact on the reduction of sodium nitrite levels in meat samples. The analysis was performed by molecular absorption spectroscopy using a UV-VIS 3100 spectrophotometer (Shimadzu, Japan). Data from measurements were analysed using Statistica 13.1. software (StatSoft, Poland). For most of the analysed processed meats, freezing significantly reduced the content of sodium nitrite (p ≤ 0.05 or p ≤ 0.01). A very significant decrease in NaNO2 was found for all cooked meat samples (p ≤ 0.01). In all analyzed products the content of this preservative was within the acceptable limits.