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

Effects of sodium nitrite reduction, removal or replacement on cured and cooked meat for microbiological growth, food safety, colon ecosystem, and colorectal carcinogenesis in Fischer 344 rats

Epidemiological and experimental evidence indicated that processed meat consumption is associated with colorectal cancer risks. Several studies suggest the involvement of nitrite or nitrate additives via N-nitroso-compound formation (NOCs). Compared to the reference level (120 mg/kg of ham), sodium nitrite removal and reduction (90 mg/kg) similarly decreased preneoplastic lesions in F344 rats, but only reduction had an inhibitory effect on Listeria monocytogenes growth comparable to that obtained using the reference nitrite level and an effective lipid peroxidation control. Among the three nitrite salt alternatives tested, none of them led to a significant gain when compared to the reference level: vegetable stock, due to nitrate presence, was very similar to this reference nitrite level, yeast extract induced a strong luminal peroxidation and no decrease in preneoplastic lesions in rats despite the absence of NOCs, and polyphenol rich extract induced the clearest downward trend on preneoplastic lesions in rats but the concomitant presence of nitrosyl iron in feces. Except the vegetable stock, other alternatives were less efficient than sodium nitrite in reducing L. monocytogenes growth.

Survival of Clostridium perfringens, Staphylococcus aureus and Salmonella enterica in alternatively cured bacon during cooking and process deviations

Pork bellies were injected with four different alternative curing brines. The bellies were inoculated on the surface and at a depth of 1 cm with multiple strains of Clostridium perfringens, Staphylococcus aureus and Salmonella enterica. The bellies were processed using either a standard process cycle or an interrupted process cycle to simulate a process deviation. Additionally, laboratory simulation of the same cycles was conducted where surface inoculated pork belly samples (22 ± 1 g) were processed in a circulating water bath. Microbiological populations were determined at the beginning, mid-point and end of the cycles, and the change in population was calculated for each bacterium at each time point, by comparing the population to the initial inoculated population. Irrespective of the brine or process cycle, the populations of all of the inoculated bacteria on both the surface and interior samples had decreased by the end of the process. There was no difference in the reductions in bacterial populations for all of the inoculated bacteria by brine type or by sample location (P > 0.30). There were differences in the microbial population reductions for C. perfringens attributable to the processing cycle (P < 0.001), with less population reductions associated with the standard cycle when compared to the interrupted cycle. However, no differences (P > 0.10) were observed in the population reductions between the two processing cycles for either S. aureus or S. enterica.

Nitrite reduction in fermented meat products and its impact on aroma

Fermented meat products are important not only for their sensory characteristics, nutrient content and cultural heritage, but also for their stability and convenience. The aroma of fermented meat products is unique and its formation mechanisms are not completely understood; however, the presence of nitrite and nitrate is essential for the development of cured aroma. The use of nitrite and nitrate as curing agents in meat products is based on its preservation activity. Even though their presence has been associated with several risks due to the formation of nitrosamines, their use is guarantee due to their antimicrobial action against Clostridium botulinum. Recent trends and recommendations by international associations are directed to use nitrite but at the minimum concentration necessary to provide the antimicrobial activity against Clostridium botulinum. This chapter discuss the actual limits of nitrite and nitrite content and their role as curing agents in meat products with special impact on dry fermented products. Regulatory considerations, antimicrobial mechanisms and actual trends regarding nitrite reduction and its effect on sensory and aroma properties are also considered.

Development of paper-based microfluidic device for the determination of nitrite in meat

This study employed the use of a microfluidic paper-based analytical device (µPAD) to determine the concentration of nitrite in pork and enhanced the limit of detection by analyzing the coffee-ring effect. The µPAD was fabricated by designing and embedding wax channels onto the cellulose-based filter paper through printing and subjecting the paper to heat treatment to allow wax penetration. Nitrite concentration was determined by monitoring the colorimetric reaction that occurred between nitrite and the added Griess reagent. The limit of detection of this device for nitrite in pork was determined to be 19.2 mg kg^-1 by analyzing the inner-chamber reaction, while it could be as low as 1.1 mg kg^-1 if the coffee-ring region was analyzed. The overall analysis could be completed within 15 min. This µPAD-based method has potential applications to routinely screen the nitrite concentration of meat products and ensure food safety and consumer health.

Quality characteristics of pork loin cured with green nitrite source and some organic acids

This study was conducted to improve the quality characteristics of cured meat with natural nitrite. Control and treatment were conducted as follows: nitrite free, marinated with sodium nitrite and ascorbic acid, marinated with only fermented spinach (FS), and marinated with FS adding ascorbic acid, malic acid, citric acid, and tartaric acid. Treatments were pickled with regulated brine (8% salt and 0.08% nitrite). Cured meat with FS adding ascorbic acid, malic acid, and citric acid had higher redness values than sodium nitrite with ascorbic acid on cooked meat. There was a positive effect on lipid oxidation except for citric acid. Protein degradation appeared more in malic acid and tartaric acid treatment than others. Residual nitrite level was lower when adding organic acids. Among various organic acid, ascorbic acid had the highest efficient on quality properties of cured meat. Thus, ascorbic acid was a proper ingredient when curing meat product.

Nitrite scavenging impact of fermented soy sauce in vitro and in a pork sausage model

The objective of this study was to determine nitrite scavenging activity of fermented soy sauce in vitro and in a pork sausage model. In vitro nitrite scavenging activity (pH 6.0) of fermented soy sauce (10 mg/mL) was 13.2%. Within selected concentrations (10-100 mg/mL), in vitro nitrite scavenging activity and total phenol content of fermented soy sauce were highly dose-dependent (P < 0.001). In pork sausage model containing 120 mg/kg of NaNO₂, fermented soy sauce resulted in significantly lower residual nitrite content (35.28 mg/kg) compared to only NaNO₂ addition (40.12 mg/kg) at initial storage. During 4 weeks of cold storage, however, fermented soy sauce showed little effect on the residual nitrite content. This study indicates that fermented soy sauce could initially contribute to reduce residual nitrite content, and the nitrite scavenging impact of fermented soy sauce was less effective in the pork sausage model than in vitro evaluation.

Effects of Nitrite and Erythorbate on Clostridium perfringens Growth during Extended Cooling of Cured Ham

To control the growth of Clostridium perfringens in cured meat products, the meat and poultry industries commonly follow stabilization parameters outlined in Appendix B, "Compliance Guidelines for Cooling Heat-Treated Meat and Poultry Products (Stabilization)" ( U.S. Department of Agriculture, Food Safety and Inspection Service [USDA-FSIS], 1999 ) to achieve cooling (54.4 to 4.4°C) within 15 h after cooking. In this study, extended cooling times and their impact on C. perfringens growth were examined. Phase 1 experiments consisted of cured ham with 200 mg/kg ingoing sodium nitrite and 547 mg/kg sodium erythorbate following five bilinear cooling profiles: a control (following Appendix B guidelines: stage A cooling [54.4 to 26.7°C] for 5 h, stage B cooling [26.7 to 4.4°C] for 10 h), extended stage A cooling for 7.5 or 10 h, and extended stage B cooling for 12.5 or 15 h. A positive growth control with 0 mg/kg nitrite added (uncured) was also included. No growth was observed in any treatment samples except the uncured control (4.31-log increase within 5 h; stage A). Phase 2 and 3 experiments were designed to investigate the effects of various nitrite and erythorbate concentrations and followed a 10-h stage A and 15-h stage B bilinear cooling profile. Phase 2 examined the effects of nitrite concentrations of 0, 50, 75, 100, 150, and 200 mg/kg at a constant concentration of erythorbate (547 mg/kg). Results revealed changes in C. perfringens populations for each treatment of 6.75, 3.59, 2.43, -0.38, -0.48, and -0.50 log CFU/g, respectively. Phase 3 examined the effects of various nitrite and erythorbate concentrations at 100 mg/kg nitrite with 0 mg/kg erythorbate, 100 with 250, 100 with 375, 100 with 547, 150 with 250, and 200 with 250, respectively. The changes in C. perfringens populations for each treatment were 4.99, 2.87, 2.50, 1.47, 0.89, and -0.60 log CFU/g, respectively. Variability in C. perfringens growth for the 100 mg/kg nitrite with 547 mg/kg erythorbate treatment was observed between phases 2 and 3 and may have been due to variations in treatment pH and NaCl concentrations. This study revealed the importance of nitrite and erythorbate for preventing growth of C. perfringens during a much longer (25 h) cooling period than currently specified in the USDA-FSIS Appendix B.

Effects of parsley extract powder as an alternative for the direct addition of sodium nitrite in the production of mortadella-type sausages - Impact on microbiological, physicochemical and sensory aspects

Increasing concern about chemical additives in processed meat has led to an increased market of uncured and alternatively cured meat products. However, the use of vegetable extracts or the exclusion of curing salt may increase the risk of greater bacterial growth and alteration of several physicochemical parameters. Therefore, in this study mortadella-type sausages, manufactured with 1.07 (V3), 2.14 (V4) and 4.29 (V5) g parsley extract powder/kg sausage meat were produced. These sausage variants were compared to an uncured (V2) and a traditionally nitrite-cured control (V1). A significantly lower Listeria monocytogenes growth was observed for V5 compared to all other variants during the storage time of 28days (P<0.05). Compared to V1, V5 presented a residual nitrite content reduced by 40% and similar a* values until day 21. Concerning texture parameters, L* and a_w values, no differences between the variants were detected. Sensory analysis showed that overall acceptance of V4 and V5 was comparable with V1.