Alternatives to nitrite in processed meat: Up to date

Nitrates/Nitrites in Food-Risk for Nitrosative Stress and Benefits

In the context of impact on human health, nitrite/nitrate and related nitrogen species such as nitric oxide (NO) are a matter of increasing scientific controversy. An increase in the content of reactive nitrogen species may result in nitrosative stress-a deleterious process, which can be an important mediator of damage to cell structures, including lipids, membranes, proteins and DNA. Nitrates and nitrites are widespread in the environment and occur naturally in foods of plant origin as a part of the nitrogen cycle. Additionally, these compounds are used as additives to improve food quality and protect against microbial contamination and chemical changes. Some vegetables such as raw spinach, beets, celery and lettuce are considered to contain high concentrations of nitrates. Due to the high consumption of vegetables, they have been identified as the primary source of nitrates in the human diet. Processed meats are another source of nitrites in our diet because the meat industry uses nitrates/nitrites as additives in the meat curing process. Although the vast majority of consumed nitrates and nitrites come from natural vegetables and fruits rather than food additives, there is currently a great deal of consumer pressure for the production of meat products free of or with reduced quantities of these compounds. This is because, for years, the cancer risks of nitrates/nitrites have been considered, since they potentially convert into the nitrosamines that have carcinogenic effects. This has resulted in the development and rapid expansion of meat products processed with plant-derived nitrates as nitrite alternatives in meat products. On the other hand, recently, these two ions have been discussed as essential nutrients which allow nitric oxide production and thus help cardiovascular health. Thus, this manuscript reviews the main sources of dietary exposure to nitrates and nitrites, metabolism of nitrites/nitrates, and health concerns related to dietary nitrites/nitrates, with particular emphasis on the effect on nitrosative stress, the role of nitrites/nitrates in meat products and alternatives to these additives used in meat products.

Effects of Citrus sinensis Essential Oil and Intrinsic and Extrinsic Factors on the Growth and ToxinProducing Ability of Clostridium botulinum Type A

Background: Considering the high fatality of botulism, the control of Clostridium botulinum and its neurotoxins has clinical importance. In this regard, using chemical preservatives, natural essential oils (Eos), and changes in the growth predisposing factors of bacteria are suitable methods to control the growth and toxin producing of C. botulinum in foods. Objective: The current survey was done to assess the effects of Citrus sinensis EO and intrinsic and extrinsic factors on the growth and toxin producing of C. botulinum type A. Materials and Methods: In this experiment with a factorial design, C. sinensis EO (0.0%, 0.015%, 0.03%, and 0.045%), nisin (0, 500, and 1500 IU/mL), nitrite (0, 20, and 60 ppm), pH (5.5 and 6.5), storage temperature (25 and 35° C), and sodium chloride (NaCl, 0.5% and 3%) were used to assess bacterial growth in the brain heart infusion medium. Finally, the mouse bioassay method was also used to assess toxicity. Results: Clostridium sinensis EO with a concentration of 0.045%, as well as the reduction of pH and temperature could significantly delay the growth of bacteria (P≤0.05) in contrast to the use of NaCl and nisin alone. However, all concentrations of sodium chloride (NaCl), nisin, and C. sinensis EO (< 0.045%) in interaction with each other, especially in combination with nitrite, showed good synergistic effects. Conclusion: These results suggested that using certain concentrations of C. sinensis EO and nisin, along with other suboptimal factors caused a significant decrease in the nitrite contents of foods with a significant reduction in the growth and toxin-producing ability of C. botulinum.

Plant extracts rich in polyphenols: antibacterial agents and natural preservatives for meat and meat products

Plant extracts contain large amounts of bioactive compounds, mainly polyphenols. Polyphenols inhibit the growth of microorganisms, especially bacteria. Their mechanism of action is still not fully understood but may be related to their chemical structure. They can cause morphological changes in microorganisms, damage bacterial cell walls and influence biofilm formation. Polyphenols also influence protein biosynthesis, change metabolic processes in bacteria cells and inhibit ATP and DNA synthesis (suppressing DNA gyrase). Due to the antioxidant and antibacterial activity of phenolic compounds, plant extracts offer an alternative to chemical preservatives used in the meat industry, especially nitrates (III). They can inhibit the growth of spoilage and pathogenic microflora, suppress oxidation of meat ingredients (lipids and proteins) and prevent discoloration. In this paper, we describe the factors that influence the content of polyphenols in plants and plant extracts. We present the antimicrobial activities of plant extracts and their mechanisms of action, and discuss the effects of plant extracts on the shelf-life of meat and meat products.

Plant derived ingredients rich in nitrates or phenolics for protection of pork against protein oxidation

A pork model system containg phenolic extracts (citrus, rosemary, and acerola), traditional Spanish food ingredients (paprika, garlic, and oregano), or natural nitrate sources (beet, lettuce, arugula, spinach, chard, celery, and watercress) were oxidized by an hydrophilic (OX_Hydro, 2,2'-azobis(2-amidinopropane)-dihydrochloride; AAPH) or lipophilic (OX_Lip, 2,2'-azobis(2,4-dimethylvaleronitrile; AMVN) radical initiator. Citrus as well as lettuce and spinach protected almost fully against protein thiol loss and showed efficient radical scavenging activity as determined by ESR spectroscopy in both oxidizing systems. Rosemary was an efficient radical scavenger in both systems, but behaved as a prooxidant on thiols in the OX_Hydro system. Acerola was also found to be prooxidative as determined by increased radical signal intensity especially in the OX_Lip system, assigned to high concentration of ascorbate in the extract. Natural nitrate sources, especially lettuce and spinach, are accordingly potential substitutes for synthetic phenolic antioxidants protecting against protein thiol oxidation and radical formation in pork.

Microbial biotransformation of N-nitro-, C-nitro-, and C-nitrous-type mutagens by Lactobacillus delbrueckii subsp. bulgaricus in meat products

Processed meats are classified by the International Agency for Research on Cancer (IARC) as carcinogenic to humans. However, information on the responsible agents and the influence of industrial processing on the increased risk of cancer is still lacking. This study aimed to use cultures of Lactobacillus delbrueckii subsp. bulgaricus LB-UFSC 01 to biodegrade harmful C-nitrous, N-nitro, and C-nitro compounds in processed meat matrix. Firstly, positive results for ethylnitrolic acid (ENA) (>5.00 μg kg^-1) and 2-methyl-1,4-dinitro-pyrrole (DNMP) (>12.0 μg kg^-1) were obtained in mortadellas produced under different experimental conditions employing preservatives and antioxidants. Mortadellas containing nitrite and sorbate in the ratio of 8:1 (w/w) yielded the highest concentrations of mutagens. However, the treatment with the LB-UFSC 01 culture was able to modulate the harmful compounds in the mortadella samples. Several analytical methods employing liquid chromatography coupled to mass spectrometry and statistical models were employed to identify the metabolites and reaction routes during microbial biotransformation. For the first time, relevant information regarding the formation and degradation of ENA and DNMP in a processed meat model simulating real conditions was presented.

Evaluation of physicochemical properties and volatile compounds of Chinese dried pork loin curing with plasma-treated water brine

The application of dielectric barrier discharge cold plasma (DBD-CP)-treated water as a novel curing process for manufacturing Chinese dried pork loin was investigated. The treatment time of DBD-CP was optimized based on the pH and nitrite level of the plasma-treated water (PTW). PTW treated for 3 min had an alkaline environment and a higher nitrite content than that at the other lengths of treatment time. Pork loins were marinated in control or PTW brine at 4 °C for 24 h and then dry-ripened for 15 days. PTW with a higher treatment voltage significantly decreased lipid oxidation of the products and led to an increased a* value (redness) and an increased residual nitrite content in products that was still within the range of use (all P < 0.05). The contents of each free amino acid increased with increasing treatment intensity (P < 0.05). There were 22 new volatile compounds generated in PTW-cured products, such as 3-methyl-butanol, hexanal and 2,3-octanedione, while six substances were lost, such as 2-pentylfuran, compared with those in the control. This study indicates that using PTW as a curing method can be a potential and effective way of producing dried pork meat products.

Apium Plants: Beyond Simple Food and Phytopharmacological Applications

Apium plants belong to the Apiaceae family and are included among plants that have been in use in traditional medicine for thousands of years worldwide, including in the Mediterranean, as well as the tropical and subtropical regions of Asia and Africa. Some highlighted medical benefits include prevention of coronary and vascular diseases. Their phytochemical constituents consist of bergapten, flavonoids, glycosides, furanocoumarins, furocoumarin, limonene, psoralen, xanthotoxin, and selinene. Some of their pharmacological properties include anticancer, antioxidant, antimicrobial, antifungal, nematocidal, anti-rheumatism, antiasthma, anti-bronchitis, hepatoprotective, appetizer, anticonvulsant, antispasmodic, breast milk inducer, anti-jaundice, antihypertensive, anti-dysmenorrhea, prevention of cardiovascular diseases, and spermatogenesis induction. The present review summarizes data on ecology, botany, cultivation, habitat, medicinal use, phytochemical composition, preclinical and clinical pharmacological efficacy of Apium plants and provides future direction on how to take full advantage of Apium plants for the optimal benefit to mankind.

Inhibitory Effect of Epigallocatechin Gallate, Epigallocatechin, and Gallic Acid on the Formation of N-Nitrosodiethylamine In Vitro

This study investigated the inhibitory effect of epigallocatechin gallate (EGCG), epigallocatechin (EGC), and gallic acid (GA) on the formation of N-nitrosodiethylamine (NDEA) in vitro. Results show that the three polyphenols are capable to block NDEA formation when the molar ratio of phenols to nitrite is higher than 0.8, and a more acidic environment is prone to promote the inhibitory potential of phenols. It is also found that the inhibitory effect tends to decrease in the order: EGCG, EGC, GA, which is in accordance with the order of their DPPH scavenging activity, suggesting that the inhibitory effect of polyphenols on NDEA formation may work through a free radical way. Kinetic study further revealed the three polyphenols react with nitrite at a much faster rate than diethylamine does (P < 0.05). By scavenging nitrite at a faster rate than the nitrosation of diethylamine, polyphenols at high concentration can significantly block NDEA formation. These observations may promote a possible application of polyphenol compounds to inhibit the formation of nitrosamines in food processing. PRACTICAL APPLICATION: The presence of N-nitrosamines in human diet should be an etiological risk factor for human cancers. This work may provide a useful guideline for phenolic compounds to inhibit the formation of nitrosamines in food processing, such as in the process of curing meats. Polyphenols have been proved to block NDEA formation under normal gastric juice condition, suggesting the intake of polyphenols is a potential way to prevent diseases caused by nitrite.

The Influence of Different Levels of Sodium Nitrite on the Safety, Oxidative Stability, and Color of Minced Roasted Beef

This study focuses on collecting actual data on the workable possibility of reducing the technological use of nitrites in beef products according to the present trends in nutrition, especially in terms of European Union (EU) food law. Measurements of safety by technological (pH value, water activity, N-nitrosamine), microbiological, oxidative stability (thiobarbituric acid reactive substances, oxidation-reduction potential), and color parameter (CIE L*a*b*, total heme pigment and heme iron) methods were taken after production and storage. The roasted beef with a reduced inclusion level of sodium nitrite (75 mg/kg and below) was more vulnerable to lipid oxidation. The quantities of primary lipid oxidation products were related to the sodium nitrite inclusion level (50–150 mg/kg). Clostridium spp., Staphylococcus aureus, and Listeria monocytogenes were not detected in any of the samples tested during all the experiments. The total count of Enterobacteriaceae increased with the decrease in sodium nitrite content, from log 2.75 cfu/g at the highest to log 6.03 cfu/g at the smallest addition of nitrite. The obtained results revealed that the addition of 100 mg/kg of sodium nitrite would be adequate for minced roasted beef, without significant unexpected effects on color, oxidative stability, and microbiological safety compared with the control (150 mg/kg).

Coriander essential oil as natural food additive improves quality and safety of cooked pork sausages with different nitrite levels

The effect of coriander essential oil (CEO) at concentrations of 0.075-0.150 μL/g on pH, color, lipid oxidation (TBARS), residual nitrite concentration and microbial growth of cooked pork sausages produced with different levels of sodium nitrite (0, 50 and 100 mg/kg) was investigated. Artificial neural networks modeling and the multi-response optimization were used to determine the optimal combinations of process parameters and storage time. Reduced concentration of sodium nitrite (60 mg/kg) in combination with 0.12 μL/g of CEO resulted in satisfying redness (a* approx. 11.1) and improved oxidative (TBARS approx. 0.12 mg MDA/kg) and microbial stability (total plate count - TPC approx. 2.50 Log CFU/g) of cooked pork sausages during refrigerated storage. Therefore, the results of this paper revealed significant antioxidative and antimicrobial activity of CEO, and consequently its high potential of utilization in processing of cooked pork sausages with enhanced quality and shelf-life.

Green Alternatives to Synthetic Antioxidants, Antimicrobials, Nitrates, and Nitrites in Clean Label Spanish Chorizo

Natural extracts obtained from fruit and vegetable processing are important sources of phenolic compounds and nitrates, with excellent antioxidant and antimicrobial properties. The aim of this study was to characterize and determine the antioxidant and antimicrobial capacity of several natural extracts (citric (Ct), acerola (Ac), rosemary (R), paprika, garlic, oregano, beet (B), lettuce (L), arugula (A), spinach (S), chard (Ch), celery (Ce), and watercress (W)), both in vitro and applied to a cured meat product (chorizo). For that, the volatile compounds by GC-MS and microbial growth were determined. The total phenolic and nitrate contents were measured and related with their antioxidant capacity (measured by DPPH, ABTS, FRAP, and ORAC methods) and antimicrobial capacity against Clostridium perfringens growth in vitro. In order to study the antioxidant and antimicrobial activities of the extracts in food, their properties were also measured in Spanish chorizo enriched with these natural extracts. R and Ct showed the highest antioxidant capacity, however, natural nitrate sources (B, L, A, S, Ch, Ce, and W) also presented excellent antimicrobial activity against C. perfringens. The incorporation of these extracts as preservatives in Spanish chorizo also presented excellent antioxidant and antimicrobial capacities and could be an excellent strategy in order to produce clean label dry-cured meat products.

Aromatic Profile, Physicochemical and Sensory Traits of Dry-Fermented Sausages Produced without Nitrites Using Pork from Krškopolje Pig Reared in Organic and Conventional Husbandry

Simple Summary

Consumers associate product quality more and more with the extrinsic cues related to the way animals are raised (animal welfare), agrobiodiversity, and tradition. Consumers also favor the reduced use of additives in products. To support the preservation of the autochthonous pig breeds, which are used marginally due to their lower productivity, it is important to enhance the market potential and value of their products. In light of consumer preferences for organic farming and product naturalness, the present study was designed to develop a nitrite-free product (salami type of dry-fermented sausage) from Krškopolje pigs (autochthonous Slovenian breed) and to evaluate if and how the husbandry system (organic or conventional) affects its quality. Results of this study demonstrated softer texture and somewhat less tasty dry-fermented sausages from pigs that were held in organic husbandry. This result could be ascribed to more unsaturated fat and the fact that sausages were produced without additives with antioxidant capacity.

Abstract

Dry-fermented sausages were produced in a traditional way, without addition of nitrites and starter cultures, from meat of an autochthonous breed (Krškopolje pig) raised either in a conventional indoor or organic husbandry system. Physicochemical and sensory analyses were performed at the end of processing to characterize their quality. Dry-fermented sausages from organic pork retained more moisture, which resulted in higher water activity and softer texture (instrumental and sensory). They were more oxidized (higher thiobarbituric acid reactive substances (TBARS)), in agreement with more unsaturated fatty acid profile, a higher score for rancid taste, and a higher relative abundance of volatiles from lipid β-oxidation. Overall, dry-fermented sausages from organic pork had lower levels of volatile compounds, particularly, those originating from spices (despite the same quantity added) and lower levels of amino-acid degradation. Sensory analysis showed that dry-fermented sausages from organic pork had less intensive and vivid color, tasted more bitter and sour, and had more off-tastes. The observed differences could be related to initial differences in raw material (differences in meat pH and level of polyunsaturated fatty acids) affecting the process of fermentation.

Combination effects of nitrite from fermented spinach and sodium nitrite on quality characteristics of cured pork loin

Objective

The purpose of this study was to investigate the effect of fermented spinach derived nitrite and sodium nitrite on cured pork loin.

Methods

The following treatments were prepared using brine (8% [w/v] salt): Control (−), no nitrite added; Control (+), 0.08% (w/v) sodium nitrite brine; T1, 0.04% (w/v) nitrite fermented spinach juice in 0.04% (w/v) sodium nitrite brine; T2, spinach juice in 0.04% (w/v) sodium nitrite brine; T3, 0.04% (w/v) nitrite fermented spinach juice used as sodium nitrite free brine; and T4, spinach juice used as sodium nitrite free brine. T2 and T4 were incubated to allow to reduce nitrate to nitrite.

Results

Spinach juice did not affect cooking loss and pH but negatively influenced flavor and overall acceptability (p<0.05). T1 samples containing synthetic and natural nitrites showed the highest redness values. Spinach juice negatively affected volatile basic nitrogen; however, thiobarbituric acid reactive substance values of T1 and T3 were similar to those of controls (+) (p>0.05). Residual nitrite content decreased with decreasing synthetic nitrite levels. T1 and control samples showed no significant differences in overall acceptability (p>0.05).

Conclusion

Thus, combined synthetic and natural nitrites improved the quality of cured pork loin.

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.

Investigation of nitrite alternatives for the color stabilization of heme-iron hydrolysates

This study investigates the potential of novel heme-ligand complexes, derived from heme-iron isolated from porcine hemoglobin by enzymatic hydrolysis, to use as pigments for meat products. Five alternatives to sodium nitrite were identified as possible heme ligands and stabilizing agents of the red conformation of heme. The effects of 4-methylimidazole, methyl nicotinate, pyrrolidine, piperidine, pyrazine and sodium nitrite (as comparative benchmark) on the color of heme-iron extract and pure hemin standard were studied in solution. The ligand affinity and heme-ligand stability was assessed over time in solution by UV-Vis absorbance spectroscopy and CIELAB color space parameters. The CIE redness score a* was used as a single measurement to propose a predictive model based on the following parameters: heme source (heme-iron extract or hemin standard), heme-to-ligand molar ratio (1:20 to 1:300), and storage time (up to 32 days). The optimal concentration at which each ligand can be added to either heme source, as well as the stability of the red color of the formed heme-ligand complexes in-solution was determined. Heme-iron extract-derived samples showed increased redness and color stability as compared to their hemin counterparts. No ligand showed as much affinity for heme as sodium nitrite. As the most promising ligand candidates, methyl nicotinate and 4-methylimidazole started to show color changes at a 1:50 molar ratio, but higher amounts (1:100 and 1:300, respectively) were required to attain the maximum redness possible with the highest stability.

Bacteriocinogenic LAB Strains for Fermented Meat Preservation: Perspectives, Challenges, and Limitations

Over the last decades, much research has focused on lactic acid bacteria (LAB) bacteriocins because of their potential as biopreservatives and their action against the growth of spoilage microbes. Meat and fermented meat products are prone to microbial contamination, causing health risks, as well as economic losses in the meat industry. The use of bacteriocin-producing LAB starter or protective cultures is suitable for fermented meats. However, although bacteriocins can be produced during meat processing, their levels are usually much lower than those achieved during in vitro fermentations under optimal environmental conditions. Thus, the direct addition of a bacteriocin food additive would be desirable. Moreover, safety and technological characteristics of the bacteriocinogenic LAB must be considered before their widespread applications. This review describes the perspectives and challenges toward the complete disclosure of new bacteriocins as effective preservatives in the production of safe and "healthy" fermented meat products.

Understanding the implications of current health trends on the aroma of wet and dry cured meat products

Meat product aroma is affected by various meat processing factors. In this review the main biochemical reactions involved in the development of meat product aroma (wet, dry cured and fermented) are fully described. Moreover, the different techniques used for key aroma elucidation in meat products are defined. The aroma compounds present in wet, dry cured and fermented meat products (sausage and whole piece) have been summarized. The mechanisms of aroma formation during the manufacture of cooked and dry/fermented meat products are described. In wet meat products the main reactions described are lipid degradation (oxidative reactions), Maillard reactions, Strecker degradation, and thiamine degradation while in dry meat products are; lipid degradation (oxidative reactions), thiamine degradation, microbial carbohydrate fermentation and microbial metabolism including complex interactions among them such as the amino acid degradation produced by lipid oxidation products. Finally, the effect of current health trends such as salt, fat and nitrifying content reduction on the development of meat product aroma is explained.

An Ultrasound Assessed Extraction Combined with Ion-Pair HPLC Method and Risk Assessment of Nitrite and Nitrate in Cured Meat

An accurate IPC-UV method was developed and validated for the determination of nitrite (NI) and nitrate (NA) in meat products. The best separation was achieved on a phenyl-hexyl column (150 mm × 4.6 mm, 3 µm) with a mobile phase composed of 25% acetonitrile and 75% buffer (2 mM disodium hydrogen phosphate and 3 mM tetrabutylammonium bromide, pH = 4). Eluents were monitored at 205 nm. Linearity ranges were 1.86 × 10^-6-7.5 µg·ml^-1 and 0.09-5.0 µg·ml^-1 for NI and NA, respectively. The correlation coefficients were greater than 0.999 for NI and NA. This method was applied to a number of processed meat products in Riyadh (n = 155). NI ranged from 1.78 to 129.69 mg·kg^-1, and NA ranged from 0.76 to 96.64 mg·kg^-1. Results showed extensive use of NI and NA; however, concentrations were within the legal limit of Saudi Arabia except for one sample. Further, the risk assessment and dietary exposure have been estimated for both NI and NA.

Biocontrol strategies for Mediterranean-style fermented sausages

Naturally fermented meat sausages have a long tradition in Mediterranean countries and are one of the most important groups of traditional foods consumed throughout Europe. Despite all the advances in food science and technology and increased regulatory requirements and concerns for safety and quality during the last decades, the challenge to control important foodborne pathogens in this type of meat products still persists. Simultaneously, growing consumer interest in safe, high quality and minimal processed products, with less additives/preservatives have driven the food industry and scientists in a crusade for innovative technologies to maintain the safety of these products by natural means. Biological control (biocontrol) fits well within this tendency. This review summarizes the latest achievements on biocontrol strategies applied to Mediterranean-style fermented sausages, namely: (i) bioprotective cultures; (ii) bacteriocins; and, (iii) essential oils (EOs).

Safer and healthier reduced nitrites turkey meat sausages using lyophilized Cystoseira barbata seaweed extract

Background Nitrite salts are still common additives in the meat industry. The present study provides a first approach on the employment of the lyophilized aqueous extract (WE) of the Tunisian seaweed Cystoseira barbata for the quality enhancement of turkey meat sausage. Methods WE was supplemented as a natural antioxidant agent to investigate its effectiveness in delaying lipid oxidation turkey meat sausages containing reduced amounts of sodium nitrites. Results On storage day 5, all concentrations of WE (0.01-0.4 %) reduced the meat lipid oxidation by approximately 36 %, as compared to the negative control containing only 80 mg/kg of meat of sodium nitrites as antioxidant. It was noted that within 15 days of refrigerated storage, a meat system containing 80 mg/kg of meat of sodium nitrites and 0.02 % and 0.04 % of WE had similar Thiobarbituric Acid Reactive Substances (TBARS) levels (19±1.32 and 17±1.12 µmol/kg of meat, respectively), which were comparable to the positive control containing sodium nitrites (150 mg/kg of meat) and 0.045 % vitamin C (18.46±1.27 µmol/kg of meat). In-depth, the metabolomic profiling using gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-quadripole-time-of-flight-mass spectrometry (LC-QTOF-MS) analyses of the Tunisian seaweed C. barbata solvent extracts showed that the main active compounds were phenolic compounds, fatty acids and sterols. Conclusions Overall, the cold medium containing C. barbata lyophilized aqueous extrac, with strong antioxidant activity and antihypertensive properties, may open the way to the development of a natural quality enhancement strategy for new functional and ever healthier reduced nitrites meat sausages based on algae.

Enhancing colour and oxidative stabilities of reduced-nitrite turkey meat sausages during refrigerated storage using fucoxanthin purified from the Tunisian seaweed Cystoseira barbata

The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory activity and the antioxidant properties, in vitro and in cured meat sausages containing reduced levels of sodium nitrite, of fucoxanthin extracted from the Tunisian brown seaweed Cystoseira barbata (CBFX). Results revealed that CBFX exhibited great scavenging activities against DPPH free radicals (EC50 = 136 μg/ml), peroxyl radicals in the linoleate-β-carotene system (EC50 = 43 μg/ml) and hydroxyl radicals generated by Fenton reaction (DNA nicking assay). A considerable ferric reducing potential was also recorded for CBFX (EC50 = 34 μg/ml). It is interesting to note that CBFX was found to modulate the ACE activity, which is the key enzyme involved in the blood pressure regulation, with an EC50 of 5 μg/ml. When fucoxanthin was supplemented, the concentration of sodium nitrite added to cured turkey meat sausages was reduced from 150 to 80 ppm, coupled with the enhancement of colour and oxidative stabilities. Thus, CBFX, with noticeable antioxidant and antihyertensive effects, could be used as a natural additive in functional foods to alleviate potential human health hazards caused by carcinogenic nitrosamines formation.

Effect of Swiss Chard (Beta vulgaris var. cicla) as Nitrite Replacement on Color Stability and Shelf-Life of Cooked Pork Patties during Refrigerated Storage

In this study, the effects of pre-converted nitrite from Swiss chard powder (PS) on the color stability and shelf-life of cooked pork patties during refrigerated storage for 28 d were investigated. Nitrite was added at a concentration of approximately 120 ppm. Five treatments were formulated as follows: Control (120 ppm nitrite), T1 (2% PS), T2 (2% pre-converted nitrite from celery powder; PC), T3 (1% PS + 60 ppm nitrite), and NC (nitrite-free). The T1 and T3 samples had higher nitrosoheme pigment contents, which were associated with the redness of the samples (p<0.05). T1 resulted in the highest redness value (p<0.05). The redness and yellowness of the cooked pork patties increased with increasing PS levels. The pH of the samples subjected to all treatments decreased with progress of the storage period (p<0.05). The pH of the T1 and T3 samples treated with PS was lower (p<0.05) than that obtained with other treatments, as PS has a lower pH value. The treatments in which PS was added were most effective for reducing the level of thiobarbituric acid reactive substances (TBARS) and the residual nitrite content relative to the control. T1 resulted in the highest flavor, off-flavor, and overall acceptability scores during storage (p<0.05). The total viable bacterial count for all treatments was below 1 Log CFU/g, and E. coli and coliform bacteria were not detected during storage. Therefore, these results suggested that pre-converted nitrite from Swiss chard powder is a potential replacement for nitrite in meat products.

Technological demands of meat processing-An Asian perspective

A rapid increase in the economy, population, industrialization, and urbanization of Asian countries has driven the fast development of their meat industries over recent decades. This consistent increase in meat production and consumption in Asia has been the major cause for the development of the global meat industry. Meat production methods and consumption are very diverse across different regions and countries in Asia, and thus, it is impossible to cover the technological demands of all Asian countries in this review. Here, we have mainly highlighted the differences in meat production methods and consumption in Asia during recent decades and the meat technology demands of three east Asian countries, namely China, Korea, and Japan, and one south Asian country, India. A brief introduction of the meat industry, in particular the production and consumption trend in these countries, is provided in this article. The technology demands for fresh and processed meat products are then reviewed.

Screening of Debaryomyces hansenii Strains for Flavor Production under a Reduced Concentration of Nitrifying Preservatives Used in Meat Products

A total of 15 Debaryomyces hansenii strains from different food origins were genetically characterized and tested on a culture medium resembling the composition of fermented sausages but different concentrations of nitrifying preservatives. Genetic typing of the D. hansenii strains revealed two levels of discrimination: isolation source or strain specific. Different abilities to proliferate on culture media containing different concentrations of nitrate and nitrite, as sole nitrogen sources and in the presence of amino acids, were observed within D. hansenii strains. Overall metabolism of amino acids and generation of aroma compounds were related to the strain origin of isolation. The best producers of branched aldehydes and ethyl ester compounds were strains isolated from pork sausages. Strains from cheese and llama sausages were good producers of ester compounds and branched alcohols, while vegetable strains produced mainly acid compounds. Nitrate and nitrite reduction affected in different ways the production of volatiles by D. hansenii.

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.

Effects of low NaNO2 and NaCl concentrations on Listeria monocytogenes growth in emulsion-type sausage

OBJECTIVE

The objective of this study was to evaluate the effect of combinations of NaNO2 and NaCl concentrations on Listeria monocytogenes (L. monocytogenes) growth in emulsion-type sausage.

METHODS

Emulsion-type sausages formulated with different combinations of NaNO2 (0 and 10 ppm) and NaCl (1.00%, 1.25%, and 1.50%) were inoculated with a five-strain L. monocytogenes mixture, and stored at 4°C, 10°C, and 15°C, under aerobic or vacuum conditions. L. monocytogenes cell counts were measured at appropriate intervals, and kinetic parameters such as growth rate and lag phase duration (LPD) were calculated using the modified Gompertz model.

RESULTS

Growth rates increased (0.004 to 0.079 Log colony-forming unit [CFU]/g/h) as storage temperature increased, but LPD decreased (445.11 to 8.35 h) as storage temperature and NaCl concentration increased. The effect of combinations of NaCl and low-NaNO2 on L. monocytogenes growth was not observed at 4°C and 10°C, but it was observed at 15°C, regardless of atmospheric conditions.

CONCLUSION

These results indicate that low concentrations of NaNO2 and NaCl in emulsion-type sausage may not be sufficient to prevent L. monocytogenes growth, regardless of whether they are vacuum-packaged and stored at low temperatures. Therefore, additional techniques are necessary for L. monocytogenes control in the product.

Listeria monocytogenes behaviour and quality attributes during sausage storage affected by sodium nitrite, sodium lactate and thyme essential oil

The effects of the addition of nitrite at 200 ppm (N), sodium lactate 1.5% (L) and thyme essential oil at 100 ppm (T1) on Listeria monocytogenes behaviour and ATPase activity inhibition were evaluated, as well as lipid oxidation through the quantification of malonaldehydes, in sausage stored at 8 ℃ for 41 days and at 30 ℃ for 14 days. The changes in the colour profile were performed during storage time at 8 ℃. Quantitative descriptive sensory analyses were performed after two days at 4 ℃. At 8 ℃, the treatments with the highest inhibition on L. monocytogenes were L and N, without significant differences. In turn, at 30 ℃, the bacterium was most inhibited with treatment L, followed by T1 and N, without significant differences. A 44.1% and 19% inhibition of ATPase activity was detected in L and T1 treatments, respectively. At 8 ℃ and 30 ℃, malonaldehydes content was not different between the treatments. N presented the highest values of a* and concentration of metmyoglobin after 41 days at 8 ℃. The panel detected differences between T1 and N for the aroma in the descriptors spices and herbal.

Health and Safety Considerations of Fermented Sausages

Fermented sausages are highly treasured traditional foods. A large number of distinct sausages with different properties are produced using widely different recipes and manufacturing processes. Over the last years, eating fermented sausages has been associated with potential health hazards due to their high contents of saturated fats, high NaCl content, presence of nitrite and its degradation products such as nitrosamines, and use of smoking which can lead to formation of toxic compounds such as polycyclic aromatic hydrocarbons. Here we review the recent literature regarding possible health effects of the ingredients used in fermented sausages. We also go through attempts to improve the sausages by lowering the content of saturated fats by replacing them with unsaturated fats, reducing the NaCl concentration by partly replacing it with KCl, and the use of selected starter cultures with desirable properties. In addition, we review the food pathogenic microorganisms relevant for fermented sausages(Escherichia coli,Salmonella enterica,Staphylococcus aureus,Listeria monocytogenes,Clostridium botulinum, andToxoplasma gondii)and processing and postprocessing strategies to inhibit their growth and reduce their presence in the products.

Electrochemical Determination of Food Preservative Nitrite with Gold Nanoparticles/p-Aminothiophenol-Modified Gold Electrode

Due to the negative impact of nitrate and nitrite on human health, their presence exceeding acceptable levels is not desired in foodstuffs. Thus, nitrite determination at low concentrations is a major challenge in electroanalytical chemistry, which can be achieved by fast, cheap, and safe electrochemical sensors. In this work, the working electrode (Au) was functionalized with p-aminothiophenol (p-ATP) and modified with gold nanoparticles (Au-NPs) to manufacture the final (Au/p-ATP-Au_nano) electrode in a two-step procedure. In the first step, p-ATP was electropolymerized on the electrode surface to obtain a polyaminothiophenol (PATP) coating. In the second step, Au/p-ATP-Au_nano working electrode was prepared by coating the surface with the use of HAuCl₄ solution and cyclic voltammetry. Determination of aqueous nitrite samples was performed with the proposed electrode (Au/p-ATP-Au_nano) using square wave voltammetry (SWV) in pH 4 buffer medium. Characteristic peak potential of nitrite samples was 0.76 V, and linear calibration curves of current intensity versus concentration was linear in the range of 0.5–50 mg·L⁻¹ nitrite with a limit of detection (LOD) of 0.12 mg·L⁻¹. Alternatively, nitrite in sausage samples could be colorimetrically determined with high sensitivity by means of p-ATP‒modified gold nanoparticles (AuNPs) and naphthylethylene diamine as coupling agents for azo-dye formation due to enhanced charge-transfer interactions with the AuNPs surface. The slopes of the calibration lines in pure NO₂⁻ solution and in sausage sample solution, to which different concentrations of NO₂⁻ standards were added, were not significantly different from each other, confirming the robustness and interference tolerance of the method. The proposed voltammetric sensing method was validated against the colorimetric nanosensing method in sausage samples.

Lactic acid bacteria as protective cultures in fermented pork meat to prevent Clostridium spp. growth

In meat fermented foods, Clostridium spp. growth is kept under control by the addition of nitrite. The growing request of consumers for safer products has led to consider alternative bio-based approaches, the use of protective cultures being one of them. This work is aimed at checking the possibility of using two Lactobacillus spp. strains as protective cultures against Clostridium spp. in pork ground meat for fermented salami preparation. Both Lactobacillus strains displayed anti-clostridia activity in vitro using the spot agar test and after co-culturing them in liquid medium with each Clostridium strain. Only one of them, however, namely L. plantarum PCS20, was capable of effectively surviving in ground meat and of performing anti-microbial activity in carnis in a challenge test where meat was inoculated with the Clostridium strain. Therefore, this work pointed out that protective cultures can be a feasible approach for nitrite reduction in fermented meat products.