Survival of Listeria innocua in dry fermented sausages and changes in the typical microbiota and volatile profile as affected by the concentration of nitrate and nitrite

Assessment of dietary exposure to food additives used in Polish processed meat products

Dietary exposure assessments have been performed for nitrites, phosphates, erythorbic acid, and sodium erythorbate in processed meat in Poland. The exposure has been estimated based on the maximum level of use of additives contained in Regulation - tier 2 and the concentration of additives in processed meat - tier 3, additionally for nitrites. Daily intake was estimated using 24-h recall, repeated three times. Exposure analyses were correlated with the frequency of occurrence of food additives based on label analysis (tiers 2a and 3a). The mean nitrite intake from processed meat at tier 2 was 0.1 mg/kg bw (143% ADI), 0.08 mg/kg bw (118% - ADI) at tier 2a, 0.03 mg/kg bw (43% - ADI) at tier 3, and 0.026 mg/kg bw (37% - ADI) at tier 3a. The mean intakes of phosphate and erythorbic acid/sodium erythorbate from processed meat were 3.26 and 0.54 mg/kg bw (8.2% and 9% - ADI), respectively at tier 2. None of the respondents exceeded the ADIs for phosphates or erythorbic acid/sodium erythorbate. In contrast, nitrite consumption is of great concern because of significant ADI exceedances, particularly among young children.

Survival of Naturally Contaminating Listeria monocytogenes in Commercial Mediterranean-Style Dry Fermented Sausages during Storage

ABSTRACT

The aim of the present study was the determination of Listeria monocytogenes, competitive microbiota, microbial hygiene indicators, and physicochemical parameters in the typical Mediterranean-style fermented sausages Salsiccia Sarda. A batch of Salsiccia Sarda (25 samples) naturally contaminated by L. monocytogenes and vacuum packaged after 24 days of ripening was included in the study. Fifteen samples stored at 8°C were analyzed after 13 days, after 90 days, and at the end of shelf life (after 180 days from vacuum packaging). Ten vacuum-packaged samples were stored at 12°C in a domestic fridge simulating temperature abuse and were evaluated at the end of the shelf life. Samples were subjected to physicochemical analysis (pH and water activity) and investigated for the presence and enumeration of L. monocytogenes. Competitive microbiota, lactic acid bacteria, coagulase-negative staphylococci, and microbial hygiene indicators (total mesophilic bacterial counts, Enterobacteriaceae, Enterococcuss spp., and Staphylococcus aureus) were determined in all the samples. Although a decreasing trend in L. monocytogenes prevalence was observed through the shelf life, the detection of this pathogen in fermented sausages confirms its ability to overcome hurdles of the manufacturing process. The results highlight the importance of the careful evaluation of the Salsiccia Sarda production process by food business operators to maintain unfavorable conditions for the growth of L. monocytogenes.

HIGHLIGHTS

Functional and Clean Label Dry Fermented Meat Products: Phytochemicals, Bioactive Peptides, and Conjugated Linoleic Acid

Consumer demand for specific dietary and nutritional characteristics in their foods has risen in recent years. This trend in consumer preference has resulted in a strong emphasis in the meat industry and scientific research on activities aimed at improving the nutritional value of fermented meat products. These types of meat products are valued by modern consumers due to their nutritional value resulting, among others, from the method of production. One of the major focuses of the current innovations includes the incorporation of bioactive compounds from plant-based food, in relation to the replacement of additives that may raise concerns among consumers (mainly nitrate and nitrite) as well as the modification of processing conditions in order to increase the content of bioactive compounds. Many efforts have been focused on reducing or eliminating the presence of additives, such as curing agents (nitrite or nitrate) in accordance with the idea of “clean label”. The enrichment of fermented meat products in compounds from the plant kingdom can also be framed in the overall strategies of functional meat products design, so that the meat products may be used as the vehicle to deliver bioactive compounds that may exert benefits to the consumer.

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.

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.

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.

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.

The effect of selected lactic acid bacterial strains on the technological and microbiological quality of mechanically separated poultry meat cured with a reduced amount of sodium nitrite

The aim of the research was to estimate the effect of selected lactic acid bacterial strains on the technological quality and microbiological stability of mechanically separated poultry meat (MSPM) cured with a reduced amount of sodium nitrite. The 5 different treatments of MSPM batters were prepared: C150 - control cured with sodium nitrite at 150 mg/kg, C50 - control cured with sodium nitrite at 50 mg/kg, PL1 - cured with sodium nitrite at 50 mg/kg and inoculated Lactobacillus plantarum SCH1 at about 107 cfu/g, PL2 - cured with sodium nitrite at 50 mg/kg and inoculated Lactobacillus brevis KL5 at about 107 cfu/g, and PL3 - cured sodium nitrite at 50 mg/kg and inoculated L. plantarum S21 at about 107 cfu/g. The MSPM batters were tested at 1, 4 and 7 d of being in refrigerated storage. The scope of the research was as follows - physicochemical determinations: pH and redox, nitrates and nitrites as well as nitrosyl pigments levels, color estimation with a Comission Internationale de l'Eclairage Lab system and microbiological determinations: the total viable counts, the mesophilic lactic acid bacteria counts, Escherichia coli and Enterobacteriaceae counts. The inhibitory effect of L. plantarum SCH1 isolated from the ecological raw fermented meat product on E. coli in cured MSPM batters during refrigerated storage was proved (P < 0.05). The use of lactic acid bacterial strains in cured batters that were prepared and based on mechanically separated poultry meat did not have a negative effect on their technological quality. The positive effect of L. brevis KL5 on the level of nitrosyl pigments in the cured MSPM batters was observed (P < 0.05). The conducted research suggested the possibility of using the selected bacterial strains of the Lactobacillus genus to improve the microbiological quality of MSPM cured with a reduced amount of sodium nitrite.

Technological parameters for the production of cooked poultry and pork sausages enriched with non-traditional vegetable raw materials

The results of the development of the technological scheme and parameters of the production of cooked sausage products from poultry and pork, enriched with protein-containing vegetable raw materials, are presented. It is proposed to introduce chickpea flour and lentil flour in a total amount of 5% in equal proportions of 1:1 into the sausage product recipe as a protein-containing vegetable additive. Previously, chickpea and lentil flour are mixed with aquafaba in different containers. Part of the water or ice introduced in the production of cooked sausages is replaced with aquafaba, obtained in the production of chickpea flour. Aquafaba is administered in an amount of 5%. These mixtures are placed in the freezer 30 minutes before the start of cooking the minced meat and kept at a temperature of -22°C for freezing. At the third stage of cutting, a frozen mixture of aquafaba, lentil and chickpea flour is added. The processing time is 3-5 minutes. This mixture in the technological process acts as a structure-forming component and improves the organoleptic properties of the finished product. The introduced additives allow you to get a functional product with an increased content of animal and vegetable protein, as well as increased vitamin and mineral value.

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.

Comparison of predicted and impedance determined growth of Listeria innocua in complex food matrices

Indirect impedance has been used for the detection and enumeration of bacteria, however there is limited data regarding the ability of the method to measure growth and inhibition of microorganisms in food in response to preservatives. The aim of this study was to evaluate the suitability of the technique to determine maximum growth rates of Listeria innocua (used as a surrogate for Listeria monocytogenes) in complex food matrices to which multiple preservative factors had been applied and assess the suitability of the data for use in predictive microbiology. Growth of L. innocua in laboratory medium (BHI broth) and two food matrices (zucchini purée and béarnaise sauce) under varying conditions of pH (5 & 5.3), water activity (0.93, 0.96 & 0.98) and acetic and propionic acid concentration (0, 1 & 2 mM) was monitored by the conductimetric Rapid Automated Bacterial Impedance Technology (R.A.B.I.T) system by means of CO₂ emission for up to 120 h. Growth rates of L. innocua were determined for several conditions across the three test matrices and a good correlation between detection times and initial inoculum level was observed in most cases (R² ≥ 0.82). However, growth of L. innocua was not detected in a large number of conditions and comparison of growth rates determined by indirect impedance to those determined by plate counts indicated that in general, the R.A.B.I.T. system under-estimated growth. This study demonstrates that there are limitations associated with the technology, and as a result the system may be unsuitable for measuring microbial growth rates in complex food matrices under the environmental conditions tested and within the time duration of the study.

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.

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).

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.

Selection of Surrogate Bacteria for Use in Food Safety Challenge Studies: A Review

Nonpathogenic surrogate bacteria are prevalently used in a variety of food challenge studies in place of foodborne pathogens such as Listeria monocytogenes, Salmonella, Escherichia coli O157:H7, and Clostridium botulinum because of safety and sanitary concerns. Surrogate bacteria should have growth characteristics and/or inactivation kinetics similar to those of target pathogens under given conditions in challenge studies. It is of great importance to carefully select and validate potential surrogate bacteria when verifying microbial inactivation processes. A validated surrogate responds similar to the targeted pathogen when tested for inactivation kinetics, growth parameters, or survivability under given conditions in agreement with appropriate statistical analyses. However, a considerable number of food studies involving putative surrogate bacteria lack convincing validation sources or adequate validation processes. Most of the validation information for surrogates in these studies is anecdotal and has been collected from previous publications but may not be sufficient for given conditions in the study at hand. This review is limited to an overview of select studies and discussion of the general criteria and approaches for selecting potential surrogate bacteria under given conditions. The review also includes a list of documented bacterial pathogen surrogates and their corresponding food products and treatments to provide guidance for future studies.

Model for Listeria monocytogenes inactivation by high hydrostatic pressure processing in Spanish chorizo sausage

A central composite design was implemented to study the effect of three factors on HHP-induced L. monocytogenes inactivation in Spanish chorizo sausage, in order to increase its effectiveness: product a_w (0.79-0.92), pressure intensities (349-600 MPa, at 18 °C) and holding time (0-12.53 min). Response surface methodology was implemented with backward stepwise regression to generate a model that best fitted to the experimental data. All the three factors studied significantly influenced HHP inactivation of L. monocytogenes (p < 0.05). Pathogen reductions increased as the pressure and duration of HHP treatments rose. Low values of a_w seemed to exert a protective effect on L. monocytogenes and pressures below 400 MPa did not lead to significant pathogen reductions. The model was validated with independent published data. Accuracy and bias factors were also determined to evaluate the performance of the developed model, which was considered acceptable for prediction purposes. The model generated represents a mathematical tool that will help food manufacturers to improve the efficacy of HHP processing of chorizo sausage and observe the regulatory authority's specifications regarding L. monocytogenes levels while maintaining food safety.

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.

Acidified nitrite inhibits proliferation of Listeria monocytogenes - Transcriptional analysis of a preservation method

Sodium nitrite (NaNO2) is added as a preservative during raw meat processing such as raw sausage production to inhibit growth of pathogenic bacteria. In the present study it was shown in challenge assays that the addition of sodium nitrite indeed inhibited growth and survival of Listeria monocytogenes in short-ripened spreadable raw sausages. Furthermore, in vitro growth analyses were performed, which took into account combinations of various parameters of the raw sausage ripening process like temperature, oxygen availability, pH, NaCl concentration, and absence or presence of NaNO2. Data based on 300 growth conditions revealed that the inhibitory effect of nitrite was most prominent in combination with acidification, a combination that is also achieved during short-ripened spreadable raw sausage production. At pH6.0 and below, L. monocytogenes was unable to replicate in the presence of 200mg/l NaNO2. During the adaptation of L. monocytogenes to acidified nitrite stress (pH6.0, 200mg/l NaNO2) in comparison to acid exposure only (pH6.0, 0mg/l NaNO2), a massive transcriptional adaptation was observed using microarray analyses. In total, 202 genes were up-regulated and 204 genes were down-regulated. In accordance with growth inhibition, a down-regulation of genes encoding for proteins which are involved in central cellular processes, like cell wall/membrane/envelope biogenesis, translation and ribosomal structure and biogenesis, transcription, and replication, recombination and repair, was observed. Among the up-regulated genes the most prominent group belonged to poorly characterized genes. A considerable fraction of the up-regulated genes has been shown previously to be up-regulated intracellularly in macrophages, after exposure to acid shock or to be part of the SigB regulon. These data indicate that the adaptation to acidified nitrite partly overlaps with the adaptation to stress conditions being present during host colonization.

Presence of Listeria monocytogenes in Mediterranean-Style Dry Fermented Sausages

The morphological, physiological and epidemiological features of L. monocytogenes, together with the severity of human listeriosis infections, make L. monocytogenes of particular concern for manufacturers of cold-stored "ready to eat" (RTE) foods. L. monocytogenes has been isolated from a wide variety of RTE foods and is responsible for several outbreaks associated with the consumption of RTE meat, poultry, dairy, fish and vegetable products. Although L. monocytogenes is among the most frequently-detected pathogens in dry fermented sausages, these products could be included in the category of RTE products in which the growth of L. monocytogenes is not favored and have rarely been implicated in listeriosis outbreaks. However, L. monocytogenes is highly difficult to control in fermented sausage processing environments due to its high tolerance to low pH and high salt concentration. In many Mediterranean-style dry fermented sausages, an empirical application of the hurdle technology often occurs and the frequent detection of L. monocytogenes in these products at the end of ripening highlights the need for food business operators to properly apply hurdle technology and to control the contamination routes of L. monocytogenes in the processing plants. In the following, through an up-to-date review of (personal and un-) published data, the main aspects of the presence of L. monocytogenes in Mediterranean-style dry fermented sausages will be discussed.