Nitrite reduction in smoked sausage: does it impact on the inhibition of C. botulinum and L. monocytogenes?

In recent years, the increased consumption of pork meat has been paralleled by rising consumer demands for food safety and quality. Nitrite, a long-standing authorised preservative in cured meat products such as cooked ham, imparts their characteristic pink colour, flavour, and texture, while also playing a crucial role in ensuring microbiological safety and shelf life extension. In line with updated regulatory recommendations, the European Commission has proposed a reduction in the maximum permitted nitrite level to 80 mg/kg. This study therefore aimed to assess the impact of such a reduction on the control of key foodborne pathogens under realistic storage conditions.

Three formulations of smoked cooked sausage were prepared: one with standard nitrite levels, one with reduced nitrite levels, and one with no nitrite. Clostridium sporogenes spores were inoculated into the raw meat prior to heat treatment, while a Listeria monocytogenes cocktail was inoculated onto sliced products post-cooking, simulating potential cross-contamination. The samples were stored at 4 °C (recommended) and at 15 °C, 20 ºC, and 30 ºC (temperature abuse scenarios). C. sporogenes was monitored over 60 days and L. monocytogenes over 35 days.

The results indicated that nitrite effectively inhibited the germination and growth of C. sporogenes during the first 10 days, with no significant differences observed between the standard and reduced nitrite formulations at any storage temperature. In contrast, nitrite delayed but did not prevent growth of L. monocytogenes, highlighting its limited efficacy against post-processing contamination. These findings support the feasibility of nitrite reduction without compromising the initial safety, while underlining the need for complementary control measures to manage L. monocytogenes.