A study on the toxigenesis by Clostridium botulinum in nitrate and nitrite-reduced dry fermented sausages

Synchronous fluorescence detection of nitrite in meat products based on dual-emitting dye@MOF and its portable hydrogel test kit

A novel ratiometric fluorescent nanoprobe (Rh6G@UIO-66-NH2) was fabricated for efficient nitrite (NO2-) detection in the present study. When NO2- was introduced, it interacted with the amino groups on the surface of Rh6G@UIO-66-NH2, forming diazonium salts that led to the quenching of blue fluorescence. With this strategy, a good linear relationship between NO2- concentration and the fluorescent intensity ratio of the nanoprobe in the range of 1-100 μM was established, with a detection limit of 0.021 μM. This dual-readout nanosensor was applied to analyze the concentration of NO2- in real meat samples, achieving satisfactory recovery rates of 94.72-104.52%, highlighting the practical potential of this method. Furthermore, a portable Gel/Rh6G@UIO-66-NH2 hydrogel test kit was constructed for on-spot dual-mode detection of NO2-. This kit allows for convenient colorimetric analysis and fluorometric detection when used in conjunction with a smartphone. All the photos taken with the portable kit was converted into digital information using ImageJ software. It provides colorimetric and fluorescent visual detection of NO2- over a range of 0.1-1.5 mM, achieving a direct quantitative tool for NO2- identification. This methodology presents a promising strategy for NO2- detection and expands the application prospects for on-spot monitoring of food safety assessment.

Reduction of carcinogens in fermented fish (pla-ra and pla-som) by heating

Background and Aim

The risk factors for cholangiocarcinoma (CCA) are opisthorchiasis and the intake of a combination of nitroso compounds through the consumption of traditionally fermented fish, which is very popular in areas where liver flukes are endemic. The incidence of CCA remains high because this cultural habit of rural people has been altered. Therefore, decreasing nitrate and nitrite concentrations in fermented fish are an alternative approach to reducing the risk of CCA. Thus, this study aimed to reduce nitrate and nitrite concentrations in fermented foods by heating and investigated its effect on CCA development in a hamster model.

Materials and Methods

We used Association of Official Analytical Chemists method 973.31 to measure the nitrate and nitrite concentrations in both fermented fish (pla-ra [PR]) and pickled fish (pla-som [PS]) before and after boiling for 5 and 30 min, respectively. The same samples were fed to Opisthorchis viverrini (OV)-infected or -uninfected hamsters for 3 months. Thereafter, the hamsters' liver and blood were collected for analysis.

Results

The levels of nitrates and nitrites in PS and PR significantly decreased following boiling for 5 and 30 min. The OV-PR and OV-PS groups showed dramatically increased numbers of inflammatory cells, fibrosis surrounding the bile duct, and focal fibrotic areas. However, after boiling the fermented dishes for 5 and 30 min, the extent of inflammatory cell infiltration and intensity of fibrosis in these groups were decreased.

Conclusion

Our findings suggest that boiling reduces nitrate and nitrite toxicity in fermented dishes, as evidenced by reduced hepatic inflammation. However, regardless of heating, kidney tissues are adversely affected when fermented meals are consumed daily.

Biocontrol of Pathogen Microorganisms in Ripened Foods of Animal Origin

Ripened foods of animal origin comprise meat products and dairy products, being transformed by the wild microbiota which populates the raw materials, generating highly appreciated products over the world. Together with this beneficial microbiota, both pathogenic and toxigenic microorganisms such as Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, Clostridium botulinum, Escherichia coli, Candida spp., Penicillium spp. and Aspergillus spp., can contaminate these products and pose a risk for the consumers. Thus, effective strategies to hamper these hazards are required. Additionally, consumer demand for clean label products is increasing. Therefore, the manufacturing sector is seeking new efficient, natural, low-environmental impact and easy to apply strategies to counteract these microorganisms. This review gathers different approaches to maximize food safety and discusses the possibility of their being applied or the necessity of new evidence, mainly for validation in the manufacturing product and its sensory impact, before being implemented as preventative measures in the Hazard Analysis and Critical Control Point programs.

Challenge tests reveal limited outgrowth of proteolytic Clostridium botulinum during the production of nitrate- and nitrite-free fermented sausages

Nitrate and nitrite salts perform a versatile role in fermented meats, including the inhibition of food pathogens (in particular proteolytic group I Clostridium botulinum). Despite the increasing interest in clean-label products, little is known about the behaviour of this pathogen in response to the removal of chemical preservatives from fermented meat formulations. Therefore, challenge tests with a cocktail of nontoxigenic group I C. botulinum strains were performed to produce nitrate/nitrite-free fermented sausages under different acidification conditions and starter culture formulations, including the use of an anticlostridial Mammaliicoccus sciuri strain. Results showed limited outgrowth of C. botulinum, even in the absence of acidification. The anticlostridial starter culture did not lead to an additional inhibitory effect. The selective plating procedure adopted within this study proofed robust to follow germination and growth of C. botulinum, inhibiting common fermentative meat microbiota. The challenge tests constitute a suitable tool to assess the behaviour of this food pathogen within fermented meats upon nitrate- and nitrite omission.

Nitrites in Cured Meats, Health Risk Issues, Alternatives to Nitrites: A Review

Nitrite is one of the most widely used curing ingredients in meat industries. Nitrites have numerous useful applications in cured meats and a vital component in giving cured meats their unique characteristics, such as their pink color and savory flavor. Nitrites are used to suppress the oxidation of lipid and protein in meat products and to limit the growth of pathogenic microorganisms such as Clostridium botulinum. Synthetic nitrite is frequently utilized for curing due to its low expenses and easier applications to meat. However, it is linked to the production of nitrosamines, which has raised several health concerns among consumers regarding its usage in meat products. Consumer desire for healthier meat products prepared with natural nitrite sources has increased due to a rising awareness regarding the application of synthetic nitrites. However, it is important to understand the various activities of nitrite in meat curing for developing novel substitutes of nitrites. This review emphasizes on the effects of nitrite usage in meat and highlights the role of nitrite in the production of carcinogenic nitrosamines as well as possible nitrite substitutes from natural resources explored also.

Genomic Diversity, Competition, and Toxin Production by Group I and II Clostridium botulinum Strains Used in Food Challenge Studies

Botulinum neurotoxins (BoNTs) produced by the bacteria Clostridium botulinum are the causative agent of human and animal botulism, a rare but serious and potentially deadly intoxication. Foodborne botulism is caused by the consumption of foods containing BoNTs, which results from contamination of foods with C. botulinum spores and toxin production by the bacteria during growth within the food. Validation of the safety of food products is essential in preventing foodborne botulism, however, limited guidance and standards exist for the selection of strains used in C. botulinum food challenge studies. Sequencing and genomics studies have revealed that C. botulinum is a large, diverse, and polyphyletic species, with physiologic and growth characteristics studied only in a few representatives. Little is known about potential growth competition or effects on toxin production between C. botulinum strains. In this study, we investigated an applied cocktail of ten C. botulinum strains, seven Group I and three Group II. Whole genome SNP alignments revealed that this strain cocktail encompasses the major clades of the Group I and II C. botulinum species. While growth competition appears to exist between several of the strains, the cocktail as a whole resulted in high levels of BoNT production.

Digital Evaluation of Nitrite-Reduced “Kulen” Fermented Sausage Quality

This study aimed to evaluate nitrite reduction impact on geometry, colour, chemical, microbiological, and sensory traits of dry sausage (kulen) traditionally prepared with red hot paprika powder. Three batches of kulen with different nitrite levels were produced and assessed: N110 (control with 110 mg/kg of sodium nitrite), N55 (55 mg/kg of sodium nitrite), and NF (without sodium nitrite). Samples for the analyses were taken on production day, after 8, 16, 24, 32, and 40 days of ripening and after 50 and 100 days of storage. Four novel digital methods for quality assessment were deployed such as computer vision system (CVS), three-dimensional (3D) laser imaging, oral processing, and temporal dominance of sensations (TDS). Reduction and removal of nitrites from the formulation of kulen did not result in significant ( $P<0.01$ ) differences in lightness ( ${\text{L}}^{\ast }$ ), redness ( ${\text{a}}^{\ast }$ ), and yellowness ( ${\text{b}}^{\ast }$ ) of the sausage surface, meat, and fat parts that were measured independently by means CVS. Sausages produced by 50% nitrite reduction (N55) showed no significant ( $P<0.01$ ) differences in terms of geometrical, chemical, colour, microbiological, and oral processing parameters compared with the control (N110) batch. On the other hand, the complete removal of nitrites from kulen formulation negatively affected biogenic amine levels and oral processing properties of the product. Nitrite reduction showed no significant effect on TDS curves among the batches. The results of this study indicate that nitrite content in traditional kulen can be reduced by 50% (55 mg/kg of sodium nitrite) without adversely affecting the various quality properties of the product.

Reduced Use of Nitrites and Phosphates in Dry-Fermented Sausages

Given consumer demand for foods with fewer artificial additives, the objective of this study was to investigate the effects of reduced use of nitrites and phosphates on dry-fermented sausage quality. Four sausage formulations were prepared: (1) control (using standard procedure with 0.2% phosphates and 110 mg/kg sodium nitrite) and formulations with (2) 50% less sodium nitrite, (3) 50% less sodium nitrite and sodium ascorbate (225 mg/kg), and (4) with standard nitrite but no phosphates. Weight loss and pH evolution were monitored during processing. The color, physicochemical (including oxidation), rheological, and sensory properties were evaluated on the finished product, as well as mold growth and microbiological status. Compared to control, nitrite reduction was associated with increased surface mold growth, reduced (3.0–4.4%) processing loss, and slightly higher oxidation (1.7 μg/kg more malondialdehyde) but without affecting instrumental color. The simultaneous addition of ascorbate reduced oxidation and improved color stability. The formulation without the phosphates resulted in increased oxidation (3.4 μg/kg more malondialdehyde) and changes in the instrumental color. The observed changes were relatively unimportant, as neither of the tested formulations influenced sensory traits or compromised microbial safety, implying that they can be used in production without any harm or even with some benefits.

Reformulation of Traditional Fermented Tea Sausage Utilizing Novel (Digital) Methods of Analysis

The main objective of this paper was to investigate the effect of fat reduction on different quality traits of tea sausage. This study also aimed to deploy the following digital methods of analysis: three-dimensional (3D) laser imaging, computer vision system and oral processing. Three batches of tea sausage with different amounts of pork back fat were manufactured: control (25%), medium fat (17.5%) and low fat (10%). Samples for the analyses were taken on the production day and after 7, 14, 21, 28 and 35 days of ripening. The fat level significantly influenced shrinkage, texture, pH, a_w, moisture and ash contents, peroxide value, acid number, number of chewing strokes, consumption time, eating rate and fat intake rate. Oxidative stability, colour and microbiological parameters were not affected by fat reduction. The results of the sensory analysis showed that the fat level can be reduced to 17.5% without negatively affecting the quality and sensory properties of the product. The ripening time of the fat-reduced tea sausage should be reduced to 28 days. A strong correlation between shrinkage and weight loss suggests the possibility of using 3D laser imaging in predicting weight loss and moisture content of dry sausages.

Two Faces of Fermented Foods-The Benefits and Threats of Its Consumption

In underdeveloped and developing countries, due to poverty, fermentation is one of the most widely used preservation methods. It not only allows extending the shelf life of food, but also brings other benefits, including inhibiting the growth of pathogenic microorganisms, improving the organoleptic properties and product digestibility, and can be a valuable source of functional microorganisms. Today, there is a great interest in functional strains, which, in addition to typical probiotic strains, can participate in the treatment of numerous diseases, disorders of the digestive system, but also mental diseases, or stimulate our immune system. Hence, fermented foods and beverages are not only a part of the traditional diet, e.g., in Africa but also play a role in the nutrition of people around the world. The fermentation process for some products occurs spontaneously, without the use of well-defined starter cultures, under poorly controlled or uncontrolled conditions. Therefore, while this affordable technology has many advantages, it can also pose a potential health risk. The use of poor-quality ingredients, inadequate hygiene conditions in the manufacturing processes, the lack of standards for safety and hygiene controls lead to the failure food safety systems implementation, especially in low- and middle-income countries or for small-scale products (at household level, in villages and scale cottage industries). This can result in the presence of pathogenic microorganisms or their toxins in the food contributing to cases of illness or even outbreaks. Also, improper processing and storage, as by well as the conditions of sale affect the food safety. Foodborne diseases through the consumption of traditional fermented foods are not reported frequently, but this may be related, among other things, to a low percentage of people entering healthcare care or weaknesses in foodborne disease surveillance systems. In many parts of the world, especially in Africa and Asia, pathogens such as enterotoxigenic and enterohemorrhagic Escherichia coli, Shigella spp., Salmonella spp., enterotoxigenic Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus have been detected in fermented foods. Therefore, this review, in addition to the positive aspects, presents the potential risk associated with the consumption of this type of products.

Nitrite-Free Implications on Consumer Acceptance and the Behavior of Pathogens in Cured Pork Loins

Cured pork loins are valued products due to their particular sensory characteristics. These products are usually prepared with nitrite to guarantee adequate color and pathogen control. The use of nitrite in meat products has been criticized due to its potential contribution to carcinogenic N-nitroso-compound formation. The present work aimed to evaluate the effect of eliminating nitrite from the manufacturing of cured loins made with wine- and water-based marinades on the color evaluation of consumers and on the behavior of Clostridium sporogenes, Listeria monocytogenes, and Salmonella. The use of nitrite in processing cured loins resulted in a color considered adequate by more than 50% of the consumers. When nitrite was not used, the color was described mainly as weak. The hedonic evaluation of cured loins did not reflect the color evaluation. The samples with a weak and an adequate color had similar hedonic evaluations. The present work did not allow us to infer the potential interest in injecting S. xylosus into meat to prepare cured loins. The use of nitrite did not affect the survival of Cl. sporogenes, L. monocytogenes, or Salmonella. The reduction in the aw was the primary determinant influencing pathogen survival. The production of nitrite-free cured loins seems possible once the control of pathogens can be achieved. However, the product will have a weaker color. Consumers appreciate sensory aspects other than color, which, combined with the positive impact of the “additive-free” claim, can support the possibility of producing cured loins without nitrite.

Inactivation of Listeria monocytogenes and Salmonella spp. in Milano-Type Salami Made with Alternative Formulations to the Use of Synthetic Nitrates/Nitrites

During the manufacture of Italian salami, a traditional meat product, a sequence of hurdles like meat fermentation, air-drying, and long ripening processes are generally sufficient to inhibit the growth of most pathogens. Furthermore, Italian salami are traditionally produced by adding synthetic nitrates/nitrites to raw meat with safety and technological aims, even if controversial opinions about their use still remain, particularly in relation to the consumer demand for natural food products. In this context, the aim of the study was to investigate the inactivation of Listeria monocytogenes and Salmonella spp. during the manufacturing process of Milano-type salami made with different formulations to evaluate the contribution of the hurdles and the vegetable or synthetic additives on the inactivation of pathogens. Thus, a challenge study was performed dividing ca. 400 kg of Milano-type salami batter into three batches: Batch (A) without nitrates/nitrites; Batch (B) with vegetable nitrates, and Batch (C) with synthetic nitrates/nitrites. The batches were separately inoculated with L. monocytogenes and Salmonella spp. and the pathogens’ survival was evaluated during the fermentation, draining, and 70-day ripening of the Milano-type salami. The pathogen counts decreased in all tested conditions, even though the highest inactivation of L. monocytogenes and Salmonella spp. (p < 0.05) was observed when nitrates or nitrites were added to the batter. This study shows how the safety of these products cannot exclude the aspect of the hurdle technology during the process, which plays a major role in the reduction of pathogens, but additives like nitrates and nitrites allow for a greater margin of safety. Thus, further studies are needed to validate the use of natural compounds as alternatives to conventional preservatives in meat products. These results may provide new information to support food business operators in producing traditional foods with alternative preservatives and competent authorities in verifying the safety of the products made with natural compounds, and to control the process parameters responsible for the synergistic effect against pathogens such as L. monocytogenes and Salmonella spp.

Survivability of Clostridioides difficile spores in fermented pork summer sausage during refrigerated storage

Background and Aim:

Clostridioides difficile is a spore-forming pathogen that causes serious enteric disease in humans. Strains have been isolated from food animals and meat, including pork, which suggest a potential for foodborne transmission. Pork summer sausage is a popular fermented meat product, which is consumed cooked or cooked to a lower internal temperature due to acidification of the product. The effect of acidity and cooking on the viability of C. difficile spores in a fermented meat product has not been determined. Therefore, the aim was to study the survivability of C. difficile spores in fermented pork summer sausage.

Materials and Methods:

Fermented pork sausages were prepared according to a commercial recipe with or without starter culture and C. difficile spores followed by fermentation at 37°C for ~12 h under 85% relative humidity until pH 5.0 was reached and further processed as cooked (>57°C) or uncooked (≤57°C) and stored at 4°C. C. difficile spores in sausages were enumerated at 1 h following inoculation and on days 0, 1, 7, 14, 21, 30, 60, and 90 of storage.

Results:

It was observed that C. difficile spore viability in control unfermented treatment was significantly different on day 0 from the fermented, fermented cooked, and control unfermented cooked treatments (p<0.05); however, there was no significant difference among the latter three treatment groups throughout 90 days of storage (p>0.05). On day 90 of storage, the unfermented control sausages yielded ~4.0 log colony-forming unit (CFU)/g of C. difficile spores compared to ~3.5 log CFU/g recovered from fermented samples and the unfermented cooked control samples identifying spore viability in all treatment groups.

Conclusion:

C. difficile spores were found to survive the acidity and cooking of fermented pork summer sausage and storage at 4°C for 3 months, thereby highlighting the need for effective intervention strategies to reduce the risk of C. difficile contamination in pork products.

Nitrate Is Nitrate: The Status Quo of Using Nitrate through Vegetable Extracts in Meat Products

Nitrate and nitrites are used to give the characteristic color to cured meat products and to preserve them. According to the scientific knowledge available at the moment, these compounds are approved as food additives based on a detailed ponderation between the potential risks and benefits. The controversy over nitrites has increased with the release of an IARC Monograph suggesting an association between colorectal cancer and dietary nitrite in processed meats. The trend in “clean label” products reinforced the concern of consumers about nitrates and nitrites in meat products. This review aims to explain the role of nitrates and nitrites used in meat products. The potential chemical hazards and health risks linked to the consumption of cured meat products are described. Different strategies aiming to replace synthetic nitrate and nitrite and obtain green-label meat products are summarized, discussing their impact on various potential hazards. In the light of the present knowledge, the use or not of nitrite is highly dependent on the ponderation of two main risks—the eventual formation of nitrosamines or the eventual out-growth of severe pathogens. It is evident that synthetic nitrite and nitrate alternatives must be researched, but always considering the equilibrium that is the safety of a meat product.

Strategies for Nitrite Replacement in Fermented Sausages and Effect of High Pressure Processing against Salmonella spp. and Listeria innocua

The development of nitrite-free meat products is a current industrial concern. Many efforts have been attempted to replace the nitrite effect in cured meats colour formation and pathogens control. Our previous work evidenced that lactic acid and a cold ripening were the best hurdle technologies for nitrite-free fermented sausages from metabolomics. In the first part of this work, we investigated the effect of lactic acid compared with both two alternative additives (glucono-D-lactone and a mix of sodium di-acetate/sodium lactate) and with low-nitrite sausages, all of them following either cold or traditional ripening. For this purpose, microbiological analysis, pH, water activity (aw), and a sensory study were performed. All nitrite-free sausages (cold or traditional ripened) showed quality and safety traits similar to low-nitrite traditionally ripened ones used as control. In addition, sensory study revealed that sausages with lactic acid were the most preferred cold ripened samples, supporting that this is an optimal strategy for the production of nitrite-free sausages. We selected this product for further studies. Indeed, in the second part, we evaluated the impact of ripening, and other hurdle technologies as High Pressure Processing (HPP) and under-vacuum storage against Listeria innocua and Salmonella spp. by a challenge test. Maximal declines were obtained for ripening along with HPP (i.e., 4.74 and 3.83 log CFU/g for L. innocua and Salmonella spp., respectively), suggesting that HPP might guarantee nitrite-free sausages safety. Although the quality of raw materials remains essential, these hurdle strategies largely contributed to nitrite-free sausages safety, offering a promising tool for the meat industry.

Microbiota and volatilome of dry-cured pork loins manufactured with paprika and reduced concentration of nitrite and nitrate

Dry-cured pork loin is a very popular meat product in Mediterranean countries. Pork-loin is manufactured rubbing curing salts, nitrite and nitrate, and spices on the surface of the loin which is then dry-cured or smoked for several months. Although nitrite-derived compounds are crucial for the microbiological safety and development of a distinct flavour, there have been recent concerns about the adverse health effects of nitrite-derived compounds driving to the reduction of curing agents in meat products. In this study, we have evaluated the differences in microbiota and aroma of dry-cured pork loins manufactured with or without paprika and reduced ingoing amounts of nitrate and nitrite. Staphylococcus dominated the microbiota of pork loins without paprika, regardless of the nitrite and nitrate reduction. On the contrary, the reduction of nitrite and nitrate in loins with paprika had an important effect on the microbiota. In these loins a codominance of Staphylococcus and Bacillus together by Enterobacteriaceae occurred. Moreover, paprika addition and reduction of nitrite and nitrate seemed to promote proliferation of lactic acid bacteria. Occurrence of these genera was correlated with the generation of free amino acids and their derived volatile compounds setting clear differences in the aroma profile of dry-cured loins.

Residual nitrite in processed meat products in Costa Rica: Method validation, long-term survey and intake estimations

Ingestion of high amounts of nitrite due processed meat consumption could produce negative effects in human health. Here, we investigate long-term residual sodium nitrite content in processed meat products in Costa Rica to provide the first estimations of nitrite daily intake. An extensively validated analytical procedure was applied for the long-term analysis of 1350 samples from 2014 to 2018. Mean residual sodium nitrite concentration was 76.5 mg kg^-1, ranging from < 11 to 278.0 mg kg^-1. Significant differences among product and meat types were found, but no temporal differences were observed. Nitrite daily intake was estimated in 0.0122 ± 0.0039 mg kg^-1 bw^-1 d^-1, which accounts for 17.4% of the acceptable daily intake (ADI). This information underlies the importance of studying residual nitrite kinetics in processed meat products as well as establishing long-term programs for the accurate estimation of nitrite daily intake rates.

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 an Iberian Chorizo Salted With a Combination of Mineral Salts (Seawater Substitute) and Better Nutritional Profile

The present study evaluated the effect of salt reduction using a seawater substitutes, at the nutritional and mineral composition, its physicochemical, biochemical, microbiological, and sensory characteristics of Iberian chorizo, compared with one elaborated with low salt content (KCl) and another with a normal salt content (CTRL). To this end, three batches of chorizo were prepared [Treatment 1: CTRL, 100% NaCl; Treatment 2: KCl, 31% KCl, and Treatment 3: SC (Winbi®), <3% NaCl]. In KCl and SC chorizo lots, values of moisture, salt, and water activity (a_w) were significantly lower (P < 0.05) than in the CTRL chorizo. The chorizo with lower salt content presented higher proteolytic activity; with the nutritional declaration “reduced Na content “with Na values 25% lower than the CTRL. In addition, using this combination caused significant effects (P < 0.05) on the mineral composition of chorizo SC, allowing the inclusion of more nutritional and health claims in its labeling under legislation. The partial substitution of NaCl for KCl (31%), caused an increase in the gumminess, chewiness, and hardness of the chorizo. The SC chorizo lost the reddish hue typical of this sausage, although it was the best sensory valued by a panel of consumers. No differences were observed in the microbiological quality of the different batches of chorizo, always fulfilling the legally established microbiological criteria.

Innovative Natural Functional Ingredients from Olive and Citrus Extracts in Spanish-Type Dry-Cured Sausage "Fuet"

The main objective of the present study was to evaluate the antioxidant capacity of hydroxytyrosol derived from synthetic (HT_s) and organic (HT_o) sources, and citrus (C) extract, by incorporating them in a dry-cured meat product: fuet. Firstly, antioxidant extracts were tested in an oxidized pork meat model system, avoiding by 100% the protein oxidation against AAPH and AMVN. After that, four batches of fuet were made, namely Control, HT_s, HT_o, and C, which incorporated antioxidant extracts as substitutes of synthetic additives. A hundred-day shelf-life study was carried out. The incorporation of phenolic extracts neither affected proximal composition, nor ripening process (airing losses, a_w, and pH), nor color development. However, the incorporation of HT increased Fe, Mn, and Si mineral content. At the same time, HT extracts inhibited lipid and protein oxidation and microbiological growth by 50%. Regarding sensory analysis, HT_o was the most unpalatable (extract flavor apparition), while HT_s and C samples were equally accepted as the Control sample. In addition, HT fuet samples showed two-fold higher antioxidant activity and total phenolic content than the Control sample. In conclusion, the use of HT_s in dry-cured sausages was demonstrated to be the best option to the development of clean label meat products, with promising antioxidant properties and the best standards of quality and acceptability.

The Possibility of Reduction of Synthetic Preservative E 250 in Canned Pork

The purpose of this study was to determine the possibility of reducing the amount of NaNO2 added to canned pork during 180 days of storage. In this study, three variants of canned pork were prepared by adding different amounts of sodium nitrite: N (100 mg/kg), NH (50 mg/kg), and NF (no nitrite). The antioxidant capacity, amount of secondary products of lipid oxidation, color intensity, and pH were analyzed after one, 60, 90, and 180 days of storage where sensory properties, water activity (aw), selected pathogenic bacteria, nitrate and nitrite residues, N-nitrosamines (NA), and cholesterol were analyzed after 1 and 180 days of storage. The redness parameter of the nitrite-free canned meat was found to be significantly lower (about 6.4) than that of the products containing sodium nitrite (N: 10.49 and NH: 9.89). During the storage period C. perfringens, L. monocytogenes, and Salmonella were detected in the products. It is not possible to completely eliminate nitrite from the canned pork production process without deteriorating the color, antioxidant properties, sensory characteristics, and health safety. However, the level of hazard chemicals such as NA, nitrate and nitrite residues can be limited by decreasing the amount of nitrite addition to 50 mg/kg. The free-radical scavenging ability for the sample with 50 mg/kg of sodium nitrite was observed to be poor, so its fortification with plant material rich in various polyphenolic substances may be necessary.

A green and efficient vortex-assisted liquid-phase microextraction based on supramolecular solvent for UV-VIS determination of nitrite in processed meat and chicken products

This paper describes a simple, efficient and rapid analytical method for extraction and determination of nitrite in meat and chicken products by vortex-assisted supramolecular solvent-based liquid phase microextraction (VA-SUPRAS-LPME) prior to spectrophotometric detection. The SUPRAS was rapidly formed by the addition of a colloidal decanoic acid suspension to tetrahydrofuran (THF). The validation studies were carried out in terms of linearity, limit of detection (LOD), limit of quantitation (LOQ), matrix effects, robustness, uncertainty measurement, precision, accuracy, and certified reference material (CRM) analysis using optimized experimental conditions. The LOD, LOQ, linearity and matrix effect were 0.035 ng mL^-1, 0.1 ng mL^-1, 0.1-300 ng mL^-1, and 9.6% respectively, with high preconcentration factor (200). The method was successfully applied for the determination of nitrite in processed products. Moreover, the results obtained by the proposed method were compared to the standard Griess method, and showed no significant differences in term of Student's t-test.

Substitution of synthetic nitrates and antioxidants by spices, fruits and vegetables in Clean label Spanish chorizo

Natural extracts obtained from fruits and vegetables processing are important sources of phenolic compounds and nitrates, with excellent antioxidant and antimicrobial properties. The aim of this study was to elaborate a Clean label dry-cured meat product (Spanish "chorizo") using Mediterranean Diet ingredients (Citrus, Acerola, Rosemary, Paprika, Garlic, Oregano, Lettuce + Arugula + Watercress, Spinach + Celery, Chard + Beet). For that, a self-life study for 150 days was carried out, when physical-chemical (colour, pH, a_w, thiol loss, volatile compounds profile), microbiological, and organoleptic changes were determined. The combination of citrus extracts and leafy green vegetables halved the hexanal and nonanal content for 150 days. In addition, this change did not affect to the sensory properties of the product, which obtained the highest acceptance avoiding the oxidative damage (colour, volatile compounds release, thiol loss) and the microbiological growth. Nevertheless, rosemary extract incorporation altered sensory quality, unless it also avoided protein and lipid oxidation, as well as microbiological growth. Otherwise, Control sample elaborated with synthetic sources of nitrates and nitrites showed a lower sensory quality due to the increased hardness, protein oxidation, hexanal, and nonanal concentrations, related to lipid oxidation, and hence, to rancid flavour apparition.

Influence of Meat Spoilage Microbiota Initial Load on the Growth and Survival of Three Pathogens on a Naturally Fermented Sausage

Meat products are potential vehicles for transmitting foodborne pathogens like Salmonella, S. aureus, and L. monocytogenes. We aimed to evaluate (1) the effect of the meat's initial natural microbiota on Salmonella, S. aureus, and L. monocytogenes growth and survival in a batter to prepare a naturally fermented sausage, made with and without curing salts and wine (2) the effect of a lactic acid bacteria (LAB) starter culture and wine on the survival of the three pathogens during the manufacturing of a naturally fermented sausage made with meat with a low initial microbial load. The results revealed that the reduced contamination that is currently expected in raw meat is favorable for the multiplication of pathogens due to reduced competition. The inhibitory effect of nitrite and nitrate on Salmonella, S. aureus, and L. monocytogenes was confirmed, particularly when competition in meat was low. In any attempt to reduce or eliminate nitrite from naturally fermented sausages, the use of LAB starters should be considered to ensure an unfavorable competition environment for pathogens. In the experiment with naturally fermented sausage, chouriço, the reduction in aw strongly inhibited the challenged pathogens, particularly when a LAB starter culture and wine were used.

Principles and applications of non-thermal technologies and alternative chemical compounds in meat and fish

Conventional methods of food preservation have demonstrated several disadvantages and limitations in the efficiency of the microbial load reduction and maintain food quality. Hence, non-thermal preservation technologies (NTPT) and alternative chemical compounds (ACC) have been considered a high promissory replacer to decontamination, increasing the shelf life and promoting low levels of physicochemical, nutritional and sensorial alterations of meat and fish products. The combination of these methods can be a potential alternative to the food industry. This review deals with the most critical aspects of the mechanisms of action under microbial, physicochemical, nutritional and sensorial parameters and the efficiency of the different NTPT (ultrasound, high pressure processing, gamma irradiation and UV-C radiation) and ACC (peracetic acid, bacteriocins, nanoparticles and essential oils) applied in meat and fish products. The NTPT and ACC present a high capacity of microorganisms inactivation, ensuring low alterations level in the matrix and high reduction of environmental impact. However, the application conditions of the different methods as exposition time, energy intensity and concentration thresholds of chemical compounds need to be specifically established and continuously improved for each matrix type to reduce to the maximum the physicochemical, nutritional and sensorial changes. In addition, the combination of the methods (hurdle concept) may be an alternative to enhance the matrix decontamination. In this way, undesirable changes in meat and fish products can be further reduced without a decrease in the efficiency of the decontamination.

Botulinum Toxin as a Biological Warfare Agent: Poisoning, Diagnosis and Countermeasures

Botulinum toxin is a neurotoxin produced by Clostridium botulinum and some other relative species. It causes a lethal disease called botulism. It can enter the body via infections by Clostridium (e.g. wound and children botulism) or by direct contact with the toxin or eating contaminated food (food-borne botulism). Botulinum toxin is also considered as a relevant biological warfare agent with an expected high number of causalities when misused for bioterrorist or military purposes. The current paper surveys the actual knowledge about botulinum toxin pathogenesis, the manifestation of poisoning, and current trends in diagnostics and therapeutics. Relevant and recent literature is summarized in this paper.

Red Wine and Garlic as a Possible Alternative to Minimize the Use of Nitrite for Controlling Clostridium Sporogenes and Salmonella in a Cured Sausage: Safety and Sensory Implications

The use of nitrite in meat products has been questioned due to its potential association with colon cancer. This work aimed to evaluate the behavior of Clostridium sporogenes (used as a surrogate for Cl. botulinum) and Salmonella in a dry-cured sausage, chouriço, made with and without nitrite and nitrate or with red wine and garlic, and to study the sensory implications through a consumer test. The survival of Cl. sporogenes and Salmonella was determined mainly by the reduction in water activity (aw), but the use of wine or wine and garlic contributed to the control of Salmonella during processing. The challenge test with Cl. sporogenes revealed no effect of the curing salts, wine, or garlic on the population of this microorganism. The use of curing salts resulted in a more reddish color that was recognized by the consumer as over-cured and artificial when compared with chouriço made with wine or wine and garlic, which were better rated in the hedonic test. In cured sausages of small caliber, the use of nitrite might be reconsidered, as the values of aw necessary to inhibit Clostridium toxinogenesis and growth are achieved rapidly.

Exploring the Ambiguous Status of Coagulase-Negative Staphylococci in the Biosafety of Fermented Meats: The Case of Antibacterial Activity Versus Biogenic Amine Formation

A total of 332 staphylococcal strains, mainly isolated from meat, were screened for antibacterial activity. Eighteen strains exhibited antibacterial activity towards species within the same genus. These antibacterial strains were further screened against Clostridium botulinum, to assess their potential as anticlostridial starter cultures for the development of fermented meat products without added nitrate or nitrite. Only Staphylococcus sciuri IMDO-S72 had the ability to inhibit all clostridial strains tested, whilst displaying additional activity against Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus. Apart from their potential as bioprotective cultures, the staphylococcal collection was also screened for biogenic amine production, as these compounds may compromise food quality. To this end, ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was applied. A low incidence of biogenic amine production was found, with tyramine and β-phenylethylamine being the most prevalent ones. Concentrations remained relatively low (< 52 mg/L) after a prolonged incubation period, posing no or little threat towards food safety. Taken together, S. sciuri IMDO-S72 could serve as an interesting candidate for the bioprotection of fermented meats as it showed promising antibacterial activity as well as absence of biogenic amine production.

High-Hydrostatic-Pressure (HHP) Processing Technology as a Novel Control Method for Listeria monocytogenes Occurrence in Mediterranean-Style Dry-Fermented Sausages

Although conventional microbial control techniques are currently employed and largely successful, their major drawbacks are related to their effects on quality of processed food. In recent years, there has been a growing demand for high-quality foods that are microbially safe and retain most of their natural freshness. Therefore, several modern and innovative methods of microbial control in food processing have been developed. High-hydrostatic-pressure (HHP) processing technology has been mainly used to enhance the food safety of ready-to-eat (RTE) products as a new pre-/post-packaging, non-thermal purification method in the meat industry. Listeria monocytogenes is a pertinent target for microbiological safety and shelf-life; due to its capacity to multiply in a broad range of food environments, is extremely complicated to prevent in fermented-sausage-producing plants. The frequent detection of L. monocytogenes in final products emphasizes the necessity for the producers of fermented sausages to correctly overcome the hurdles of the technological process and to prevent the presence of L. monocytogenes by applying novel control techniques. This review discusses a collection of recent studies describing pressure-induced elimination of L. monocytogenes in fermented sausages produced in the Mediterranean area.

Review of Electrochemical DNA Biosensors for Detecting Food Borne Pathogens

The vital importance of rapid and accurate detection of food borne pathogens has driven the development of biosensor to prevent food borne illness outbreaks. Electrochemical DNA biosensors offer such merits as rapid response, high sensitivity, low cost, and ease of use. This review covers the following three aspects: food borne pathogens and conventional detection methods, the design and fabrication of electrochemical DNA biosensors and several techniques for improving sensitivity of biosensors. We highlight the main bioreceptors and immobilizing methods on sensing interface, electrochemical techniques, electrochemical indicators, nanotechnology, and nucleic acid-based amplification. Finally, in view of the existing shortcomings of electrochemical DNA biosensors in the field of food borne pathogen detection, we also predict and prospect future research focuses from the following five aspects: specific bioreceptors (improving specificity), nanomaterials (enhancing sensitivity), microfluidic chip technology (realizing automate operation), paper-based biosensors (reducing detection cost), and smartphones or other mobile devices (simplifying signal reading devices).

A Review of the In Vivo Evidence Investigating the Role of Nitrite Exposure from Processed Meat Consumption in the Development of Colorectal Cancer

The World Cancer Research Fund (WCRF) 2007 stated that the consumption of processed meat is a convincing cause of colorectal cancer (CRC), and therefore, the public should avoid it entirely. Sodium nitrite has emerged as a putative candidate responsible for the CRC-inducing effects of processed meats. Sodium nitrite is purported to prevent the growth of Clostridium botulinum and other food-spoiling bacteria, but recent, contradictory peer-reviewed evidence has emerged, leading to media reports questioning the necessity of nitrite addition. To date, eleven preclinical studies have investigated the effect of consuming nitrite/nitrite-containing meat on the development of CRC, but the results do not provide an overall consensus. A sizable number of human clinical studies have investigated the relationship between processed meat consumption and CRC risk with widely varying results. The unique approach of the present literature review was to include analysis that limited the human studies to those involving only nitrite-containing meat. The majority of these studies reported that nitrite-containing processed meat was associated with increased CRC risk. Nitrite consumption can lead to the formation of N-nitroso compounds (NOC), some of which are carcinogenic. Therefore, this focused perspective based on the current body of evidence links the consumption of meat containing nitrites and CRC risk.

Mechanisms of the bactericidal effects of nitrate and nitrite in cured meats

For cured meat products, nitrite is recognized for its antimicrobial effects against pathogenic bacteria, even though the specific inhibitory mechanisms are not well known. Nitrite contributes to oxidative stress by being the precursor of peroxynitrite (ONOO^-), which is the major strong oxidant. Thus, bacterial stress (highly pH-very low partial pressure of oxygen-dependent) is enhanced by the nitrate-nitrite-peroxynitrite system which is also highly pH- and low partial pressure of oxygen-dependent. Nitrite is a hurdle technology which effectiveness depends on several other hurdle technologies including sodium chloride (accelerating the autoxidation of oxymyoglobin and promote peroxynitrite formation), ascorbate (increasing ONOO^- synthesis), and Aw. In this environment, certain species are more resistant than others to acidic, oxidative, and nitrative stresses. The most resistant are gram-negative aerobic/facultative anaerobic bacteria (Escherichia coli, Salmonella), and the most fragile are gram-positive anaerobic bacteria (Clostridium botulinum). This position review highlights the major chemical mechanisms involved, the active molecules and their actions on bacterial metabolisms in the meat ecosystem.

Salmonella Brandenburg in the pork chain in Italy: Genetic comparison with the human isolates

Salmonella Brandenburg ranked 16th among the serovars responsible for human infections in EU in 2015 and it was found to be associated with swine. In Emilia- Romagna and Lombardy regions of northern Italy, S. Brandenburg was isolated from mesenteric lymph nodes, fecal matter, carcasses and conveyor belts at pig slaughterhouses in 2014 and 2015. In the same area, S. Brandenburg was detected in pork salami in 2015. In the present study, 12 isolates of S. Brandenburg recovered from the pork food-chain were typed by XbaI PFGE and their three profiles were compared to all human S. Brandenburg isolates processed by the Surveillance System of Emilia- Romagna region from 2012 to 2017 (105 isolates). The most frequent pulsotype of porcine origin (6/12) was the second most frequent in humans (16/105). Of the other two pulsotypes of porcine origine (3/12 each), one was the most frequent in humans (41/105), the other was undetected among human isolates.

Mathematical Model for Predicting the Growth Probability of Staphylococcus aureus in Combinations of NaCl and NaNO2 under Aerobic or Evacuated Storage Conditions

The objective of this study was to describe the growth patterns of Staphylococcus aureus in combinations of NaCl and NaNO₂, using a probabilistic model. A mixture of S. aureus strains (NCCP10826, ATCC13565, ATCC14458, ATCC23235, and ATCC27664) was inoculated into nutrient broth plus NaCl (0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, and 1.75%) and NaNO₂ (0, 15, 30, 45, 60, 75, 90, 105, and 120 ppm). The samples were then incubated at 4, 7, 10, 12 and 15℃ for up to 60 d under aerobic or vacuum conditions. Growth responses [growth (1) or no growth (0)] were then determined every 24 h by turbidity, and analyzed to select significant parameters (p<0.05) by a stepwise selection method, resulting in a probabilistic model. The developed models were then validated with observed growth responses. S. aureus growth was observed only under aerobic storage at 10-15℃. At 10-15℃, NaCl and NaNO₂ did not inhibit S. aureus growth at less than 1.25% NaCl. Concentration dependency was observed for NaCl at more than 1.25%, but not for NaNO₂. The concordance percentage between observed and predicted growth data was approximately 93.86%. This result indicates that S. aureus growth can be inhibited in vacuum packaging and even aerobic storage below 10℃. Furthermore, NaNO₂ does not effectively inhibit S. aureus growth.

Influence of bicarbonate on the abundance of microbial communities capable of reducing U(vi) in groundwater

7 experiments amended with 0, 5, 10, 15, 20, 25 and 30 mM initial concentrations of bicarbonate were conducted to investigate the influence of different concentrations of bicarbonate on the abundance of microbial communities capable of reducing U(vi) in groundwater.

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.