Residual nitrite and nitrate in processed meats and meat analogues in the United States

Residual nitrite (NO2-) and nitrate (NO3-) have been widely studied in the past few decades for their function to improve processed meat quality and their impact on human health1-4. In this study we examined how the residual nitrite and nitrate (NOx-) content of major classes of processed meats products (n = 1132) produced locally from three regions (East Coast, Midwest and West Coast) and plant protein-based meat analogues (n = 53) available at retail in the United States was influenced by their composition, processing, and geographical attributes. We also conducted time-dependent depletion studies and observed different patterns of NOx- depletion and conversion during processing and storage and correlated them with product quality. Together, our results reveal a comprehensive prospective of NOx- content in processed meats and meat analogues. The NO2- in processed meats and meat analogues averaged (± standard error; minimum and maximum value in parentheses) 13.7 ± 0.62 (0.0-214.5) and 1.7 ± 0.34 (0.0-11.0), respectively, and the NO3- in processed meats and meat analogues averaged 32.6 ± 0.90 (2.0-205.9) and 7.2 ± 0.56 (4.0-25.3) ppm, respectively.

Effect of Nitrite-Embedded Packaging Film on Growth of Listeria monocytogenes in Nitrite-free and Conventionally-cured Bologna Sausage

Listeria monocytogenes is a pathogen frequently associated with ready-to-eat (RTE) meat and poultry products. Nitrite is a key antimicrobial additive that can offer some degree of protection against L. monocytogenes when included in meat product formulations. The objectives of this study were to determine the potential of nitrite-embedded film to affect the growth of L. monocytogenes following postthermal processing of conventionally-cured and nitrite-free bologna. Two bologna treatment formulations, a conventionally-cured control formulation (CON) and a nitrite-free formulation (UCC), were manufactured, packaged in conventional (CF) or nitrite-embedded (NEF) film, inoculated with 3.5 log CFU/cm2 of a cocktail of L. monocytogenes strains, and stored at 10 ± 1 °C. CON-NEF and UCC-NEF treatments had significantly slower (P < 0.05) growth of L. monocytogenes than CON-CF and UCC-CF, with populations in UCC-CF (which contained no nitrite) increasing by 3.4 logs after 10 d of storage in UCC-CF and 3.6 logs after 50 d in CON-CF (which had formulated nitrite only), while in the NEF-packaged samples, with or without formulated nitrite, they did not exceed the inoculum level until after day 40. Initial (day 0) residual nitrite was significantly greater (P < 0.05) in the control formulation. Packaging in NEF, however, resulted in an increase of 27-28 ppm by day 3, regardless of formulation, after which it decreased rapidly. Results suggest NEF can be used as a post-lethality antimicrobial intervention in food safety intervention strategies, in both cured and uncured processed meat products.

Clean labelling sodium nitrite at pilot scale: In-situ reduction of nitrate from plant sources and its effects on the overall quality and safety of restructured cooked ham

Growing health and environmental concerns have increased demand for all-natural products, with a focus on clean labelling. Sodium nitrite is the most widely used additive in the meat industry because it imparts the typical cured flavour and colour to meat products and, most importantly, their microbiological safety. However, due to health concerns, the European Commission is proposing revised regulations to reduce nitrate and nitrite levels in meat products. As a result, the meat industry is actively seeking alternatives. This study explored the production of four cooked hams utilising nitrate-rich vegetable sources combined with two different nitrate-reducing commercial food cultures, alongside a control ham prepared with sodium nitrite (150 ppm). Microbiological, physico-chemical (pH, water activity, nitrate and nitrite concentration, lipid profile, lipid oxidation) and sensory (texture and colour profile) characterisation of the products was carried out. Challenge tests for Listeria monocytogenes, Clostridium sporogenes and Clostridium perfringens have been performed to assess the growth of pathogens, if present in the products. Results revealed comparable microbiological and physico-chemical profiles across ham formulations, with minor differences observed in colour parameters for sample C. The sensory analysis showed that for the pilot ham formulations A and D, there were no significant differences in consumer perception compared to the control ham. In the challenge tests, L. monocytogenes levels were similar in both control and tested hams. There were no significant differences in C. sporogenes and C. perfringens counts at any temperature or between test and control samples. These results indicate that this technology has a potential future in the cured meat sector, as regulators mandate the reduction of added synthetic chemicals and consumers seek healthier and more natural ingredients in their daily diets.

Investigating the Effects of Pink-Generating Ligands on Enhancing Color Stability and Pigment Properties in Pork Sausage Model Systems Cured with Sodium Nitrite or White Kimchi Powder

In this study, we investigated the effects of different nitrite sources (sodium nitrite or white kimchi powder) and pink-generating ligands (cysteine, histidine, or nicotinamide) on the development and stability of cured meat color in pork sausage model systems over 30 d of refrigerated storage. The samples were prepared in a 2 × 3 factorial design with two nitrite sources and three ligands, and their physicochemical properties were evaluated on days 0, 15, and 30. Although white kimchi powder induced cured color development similar to that of synthetic sodium nitrite, it resulted in higher cooking loss and lower residual nitrite content in cured pork sausages (p < 0.05). The addition of cysteine resulted in significantly higher CIE a* values, cured meat pigment, and curing efficiency than histidine and nicotinamide (p < 0.05), while yielding lower pH values, residual nitrite content, and total pigment content (p < 0.05). The storage duration significantly reduced the residual nitrite and total pigment contents of the products. These findings suggest that white kimchi powder can serve as a natural alternative to sodium nitrite in pork sausage models and that the incorporation of cysteine has a favorable impact on the development and enhancement of cured meat color.

Plasma-activated milk powder as a sodium nitrite alternative in pork sausages

This study investigated the effect of plasma activated milk powder containing 1.3 g/kg nitrite as an alternative to sodium nitrite in stored pork sausages. Control samples (NC) did not contain a nitrite source, while the recipes of other treatments contained 100 ppm sodium nitrite (PC), 5% plasma activated milk powder (PAMP), and 5% plasma activated milk powder with 0.05% ascorbic acid (PAMP+AA). The obtained results showed both experimental groups were characterized by higher values of residual nitrite, nitrosylhemochrome and redness as well as similar or lower values of thiobarbituric acid reactive substances and total aerobic plate count compared to PC group after the storage period. Using ascorbic acid promoted reduction of nitrite content and extended the color stability of the samples compared to PAMP group without deteriorating the oxidative and microbiological quality of the product. Finally, sausages cured using the proposed alternative method exhibited higher cooking yield, lighter color, better texture, and different aroma profile (PCA) than those with sodium nitrite.

Natural alternatives for processed meat: Legislation, markets, consumers, opportunities and challenges

Consumers' interest in food with less and/or free from synthetic additives has increased considerably in recent years. In this context, researchers and industries have concentrated efforts on developing alternatives to these compounds. Replacing synthetic additives in meat products is a challenge, given their importance for sensory characteristics and food safety. Complementary technologies combined with the replacement and/or reduction of synthetic additives (hurdle technologies) has been studied focusing on the protection and extension of the shelf life of meat products. This review reports alternatives for replacing and/or reducing the use of synthetic additives in meat derivatives, aiming at the development of more natural and simpler meat products, familiar to consumers and considered clean labels.

Chemistry, safety, and regulatory considerations in the use of nitrite and nitrate from natural origin in meat products - Invited review

Nitrite and nitrate have been traditionally used for the preservation of meat products because of the effective antimicrobial action of nitrite against Clostridium botulinum, the outgrowth of its spores as well as other bacteria. However, the use of nitrite and nitrate has been questioned in last half century due to the possible generation of N-nitrosamines through reaction of nitrite with secondary amines. Nitrite replacement strategies began in the 70s addressing these issues and instigated searches for natural alternatives to nitrate and nitrite, or for natural sources of nitrite and nitrate such as vegetable extracts. These alternatives have been considered by producers and consumers as an attractive practice even though they may also have some risks. This manuscript reviews and discusses the chemistry, safety, and regulatory considerations in the use of nitrite and nitrate from natural origin for the preservation of meat products.

Effect of Differing Ingredients and Packaging Technologies on the Color of High-Pressure Processed Ground Beef

High-pressure processing (HPP) is a nonthermal pasteurization technique to control pathogens, like Escherichia coli. However, color changes in raw beef induced by HPP restrict its use within the beef industry. The objectives of this study were to investigate the effects of adding curing agents (nitrite) and packaging with or without reducing compounds (ascorbic acid/erythorbate) on color retention in high-pressure processed ground beef. Color was measured (CIE L∗a∗b∗) before HPP and on days 3, 7, 12, 14, 19, and 21 after HPP. Statistical analysis (SAS GLIMMIX) was run to identify the main effects of adding curing agents, packaging, and reducing agents on color retention. HPP resulted in a detrimental effect on the color of the beef patties for all treatments. Lightness and yellowness increased (P<0.001) and redness decreased (P<0.001) after high-pressure processing. The effect remained the same throughout the course of the study. However, there were less color changes in samples treated with reducing compounds. Both synthetic and natural sources of nitrite and ascorbic acid/erythorbate performed similarly in terms of their ability to maintain redness. Treatments leading to formation of nitrosylmetmyoglobin (Fe3+) had less severe color change compared to the treatments leading to the generation of nitrosylmyoglobin (Fe2+).