Nitrite reduction in cooked pork ham: a risk for food safety?

Description

Cooked pork ham is formulated with nitrite, an authorised preservative that, combined with other hurdles, has been used for decades to ensure the microbiological safety of cured meat products. However, the presence of nitrites in foods can lead to the formation of nitrosamines, some of which are carcinogenic [1]. For this reason, revised regulation of the European Commission defines maximum levels of 80 mg ok nitrite per kg of meat [1]. Given this, the aim of this research was to evaluate how reducing nitrite levels in cooked ham, from 150 ppm (standard product) to 80 ppm, affects the behaviour of Listeria monocytogenes (LM). For that, slices (10-12 g) of the two formulations of ham were inoculated with a cocktail of seven LM strains (~4.5 log CFU/g), packed under MAP (80% N2, 20% CO2) and stored at 4 ºC and 8 ºC for 35 days. At specific days, LM was enumerated in PALCAM agar, and the Baranyi and Roberts model was used to describe pathogen growth. Two independent replicates were carried out. At either of the temperatures tested, the reduction of nitrite from 150 ppm to 80 ppm did not reveal a considerable impact on the maximum growth rate of the pathogen (μmax; log CFU/g day-1). At 4 °C, μmax was 0.071 ± 0.011 (150 ppm) and 0.068 ± 0.016 (80 ppm). At 8 °C, the maximum rate was 0.111 ± 0.019 (150 ppm) and 0.117 ± 0.017 (80 ppm). These results suggest that an increase of 4 ºC in temperature has a bigger impact on LM growth rate in cooked ham than a reduction of ~46% in its nitrite content. Reformulation of any food product requires careful consideration to ensure that food safety is maintained. In this case, it appears that reducing nitrite levels by nearly 50% does not promote the growth of LM in cured pork meat. This is an encouraging finding for the cured meat industry, as it supports the potential for reformulating products with lower nitrite levels.

Period	Sept 2025
Event title	13th International Conference of Predictive Modelling in Food
Event type	Conference
Location	Athens, GreeceShow on map