Modeling the Impact of Ingoing Sodium Nitrite, Sodium Ascorbate, and Residual Nitrite Concentrations on Growth Parameters of Listeria monocytogenes in Cooked, Cured Pork Sausage

Abstract

Sodium nitrite has been identified as a key antimicrobial ingredient to control pathogens in ready-to-eat (RTE) meat and poultry products, including Listeria monocytogenes. This study was designed to more clearly elucidate the relationship between chemical factors (ingoing nitrite, ascorbate, and residual nitrite) and L. monocytogenes growth in RTE meats. Treatments of cooked, cured pork sausage (65% moisture, 1.8% salt, pH 6.6, and water activity 0.98) were based on response surface methodology with ingoing nitrite and ascorbate concentrations as the two main factors. Concentrations of nitrite and ascorbate, including star points, ranged from 0 to 352 and 0 to 643 ppm, respectively. At one of two time points after manufacturing (days 0 and 28), half of each treatment was surface inoculated to target 3 log CFU/g of a five-strain L. monocytogenes cocktail, vacuum packaged, and stored at 7°C for up to 4 weeks. Growth of L. monocytogenes was measured twice per week, and enumerations were used to estimate lag time and growth rates for each treatment. Residual nitrite concentrations were measured on days 0, 4, 7, 14, 21, and 28, and nitrite depletion rate was estimated by using first-order kinetics. The response surface methodology was used to model L. monocytogenes lag time and growth rate based on ingoing nitrite, ascorbate, and the residual nitrite remaining at the point of inoculation. Modeling results showed that lag time was impacted by residual nitrite concentration remaining at inoculation, as well as the squared term of ingoing nitrite, whereas growth rate was affected by ingoing nitrite concentration but not by the remaining residual nitrite at the point of inoculation. Residual nitrite depletion rate was dependent upon ingoing nitrite concentration and was only slightly affected by ascorbate concentration. This study confirmed that ingoing nitrite concentration influences L. monocytogenes growth in RTE products, yet residual nitrite concentration contributes to the antimicrobial impact of nitrite as well.

Antioxidant and Effects of Processing Using Bixin Potassium Salt as a Nitrite Replacement in Restructured Meat Products

“…On the other hand, no effect was observed in the BIX broth. This study confirmed that ingoing nitrite concentration influences L. monocytogenes growth as observed previously (KING et al 2016), but single bixin potassium salt is not able to inhibit pathogen growth. The results show how the use of bixin could allow a reduction in the use of nitrite.…”

Reduction, removal or replacement of sodium nitrite in a model of cured and cooked meat: a joint evaluation of consequences on microbiological issues in food safety, colon ecosystem and colorectal carcinogenesis

“…Moreover, it should be noted that the presence of sodium ascorbate (0.3 g/kg) in the different recipes (Ni-120, Ni-90) may have enhanced the anti listerial effect of sodium nitrite as previously described by others. [15,48] Among the three alternative products that were tested as nitrite salt replacement, the vegetable stock (VS) gave, for almost all the parameters tested, results that were very close to those of Ni-120, whatever the dose of the food additive. Indeed, results on luminal lipid peroxidation and ATNC formation with different concentrations of vegetable stock are similar to nitrites doses of 120, (Figure 6A-B), 80 or 40 mg/kg (Figure S1A-B).…”

“…The present study showed that sodium nitrite added in the cooked ham products exerted an inhibitory effect against L. monocytogenes, as previously reported on various ready-to-eat cooked meat products. [15][16][17]48] Although sodium nitrite alone was not sufficient to prevent the growth of L. monocytogenes during actual shelf life of sliced cooked ham products, ingoing amounts of sodium nitrite equal or greater than 90 mg NaNO2 / kg led to a significant reduction of L. monocytogenes growth during the first 3 weeks of storage compared to the control without nitrite (Ni-0). Moreover, it should be noted that the presence of sodium ascorbate (0.3 g/kg) in the different recipes (Ni-120, Ni-90) may have enhanced the anti listerial effect of sodium nitrite as previously described by others.…”

“…Moreover, it should be noted that the presence of sodium ascorbate (0.3 g/kg) in the different recipes (Ni-120, Ni-90) may have enhanced the anti listerial effect of sodium nitrite as previously described by others. [15,48]…”

A study on the application of natural extracts as alternatives to sodium nitrite in processed meat

“…Although nitrates/nitrites inhibit the growth of Clostridium botulinum spores (Lebrun et al., 2020), other research studies have demonstrated that maximum acceptance levels in foods allowed by law are not enough to inhibit the growth of concern foodborne pathogens such as Listeria monocytogenes , Bacillus cereus , Staphylococcus aureus , Clostridium perfringens or Pseudomonas spp. (Cenci‐Goga et al., 2014; Grispoldi et al., 2019; Hospital et al., 2017; King et al., 2016; Rossi et al., 2016). The characteristic reddish color of meat products made with nitrates/nitrites is caused by myoglobin, an iron and oxygen‐binding protein found in skeletal muscles (Suman et al., 2016).…”