Production Of Dry Fermented Sausages Research Articles

Genomic insights of Salmonella isolated from dry fermented sausage production chains in Spain and France.

The presence of Salmonella in dry fermented sausages is source of recalls and outbreaks. The genomic diversity of 173 Salmonella isolates from the dry fermented sausage production chains (pig carcasses, pork, and sausages) from France and Spain were investigated through their core phylogenomic relationships and accessory genome profiles. Ten different serovars and thirteen sequence type profiles were identified. The most frequent serovar from sausages was the monophasic variant of S.Typhimurium (1,4,[5],12:i:-, 72%) while S. Derby was in pig carcasses (51%). Phylogenomic clusters found in S.1,4,[5],12:i:-, S. Derby, S. Rissen and S.Typhimurium serovars identified closely related isolates, with less than 10 alleles and 20 SNPs of difference, displaying Salmonella persistence along the pork production chain. Most of the S. 1,4,[5],12:i:- contained the Salmonella genomic island-4 (SGI-4), Tn21 and IncFIB plasmid. More than half of S. Derby strains contained the SGI-1 and Tn7. S.1,4,[5],12:i:- genomes carried the most multidrug resistance genes (91% of the strains), whereas extended-spectrum β-lactamase genes were found in Typhimurium and Derby serovars. Salmonella monitoring and characterization in the pork production chains, specially S. 1,4,[5],12:i:- serovar, is of special importance due to its multidrug resistance capacity and persistence in dry fermented sausages.

Influence of Common Reducing Agents on Technological Parameters of Dry-Fermented Sausages with Low Fat Content.

The production of dry-fermented sausages currently presents several challenges to be addressed: nutrition, health, sensory traits and technology are among the main issues that concern consumers and the meat industry. The objective of this study was to evaluate the effect of different reducing agents commonly used in the manufacture of dry-fermented sausages (salchichon type) with low fat content on the technological characteristics of the product. Four different reducing agents (ascorbic acid, a starter culture, sodium ascorbate and glucono-delta-lactone) were added to the meat batter to assess their impact on the physico-chemical traits, instrumental color, residual nitrates and nitrites and lipid oxidation of this meat product. High nitrate values were observed during both ripening and storage periods. All batches presented lipid oxidation values below the threshold that indicates meat rancidity. Adjustments of the original lean:fat proportion must be carried out on this low fat content sausage to obtain profitable results. Starter culture and sodium ascorbate have shown the best reducing and antioxidant activities among the additives studied. Once we have the technical design of the product, the next step will be oriented to identify the sensory characteristics in order to find a gap in the market.

Indigenous Microbiota to Leverage Traditional Dry Sausage Production.

The main issue addressed in this review is the need for innovation in the artisanal production of dry fermented sausages—leveraging rather than discarding tradition, together with some practical strategies available to achieve it. Throughout the text, emphasis is placed on the autochthonous microbiota responsible for the identity and unique sensory characteristics of these products. The available strategies to introduce innovation in this manufacturing process rely on metabolic flexibility of microbial strains. In this sense, this review evaluates the application of several tools aimed at improving the quality and safety of artisanal dry fermented sausages focusing on the microbial community role. The most studied alternatives to enhance dry sausage production comprise the use of autochthonous starter cultures—including functional and/or probiotic strains, the production of bacteriocins, and the generation of bioactive peptides, which have been thoroughly covered herein. The purpose of this work is to review recent research about novel different strategies available for food technologists to improve safety and quality in the manufacture of dry fermented sausages. Additional support strategies—quality product registers and innovation through tradition—have been suggested as complementary actions towards a successful introduction of indigenous microbial communities into traditional dry sausage production.

Dry Fermented Sausages with Total Replacement of Fat by Extra Virgin Olive Oil Emulsion and Indigenous Lactic Acid Bacteria.

SUMMARYResearch backgroundFormulations based on vegetable or fish oil and modifications in the production technology of dry fermented sausages have emerged in recent years aiming to achieve the desirable target of reducing the fat content of these meat products. However, previous efforts have confronted many difficulties, such as high mass loss and unacceptable appearance due to intensely wrinkled surfaces and case hardening. The objective of this study is to produce and evaluate dry fermented sausages by utilising a meat protein-olive oil emulsion as fat substitute and indigenous lactic acid bacteria (LAB) with probiotic properties isolated from traditional Greek meat products.Experimental approachA novel formulation with extra virgin olive oil and turkey protein was developed to totally replace the conventionally added pork fat. Probiotic and safety characteristics of autochthonous LAB isolates from spontaneously fermented sausages were evaluated and three LAB isolates were finally selected as starter cultures. Physicochemical, microbiological and sensory analyses were carried out in all treatments (control, Lactobacillus acidophilus, L. casei, L. sakei and Pediococcus pentosaceus) during fermentation.Results and conclusionsReady-to-eat sausages were found to be microbiologically stable. The olive oil-based formulation produced in this study generated a mosaic pattern visible in the sliced product simulating the fat in conventional fermented sausages and was regarded as an ideal fat substitute for the production of fermented sausages. An autochthonous isolate of Lactobacillus casei adapted the best to the final products as it was molecularly identified to be present in the highest counts among the LAB isolates used as starter cultures.Novelty and scientific contributionΑ novel and high-quality dry fermented meat product was produced by replacing the added pork fat with a fat substitute based on a meat protein-olive oil emulsion. Autochthonous LAB with in vitro probiotic properties could have a potential use in large-scale novel dry fermented sausage production. Such isolates could be used as starters in an effort to standardise the production process and retain the typical organoleptic and sensory characteristics. Moreover, isolates like L. casei 62 that survived in high counts in the final products can increase the safety of fermented sausages by competing not only with pathogens but also with the indigenous microbiota and could have a potential functional value for the consumer.

Co-extruded alginate as an alternative to collagen casings in the production of dry-fermented sausages: Impact of coating composition

The performance of co-extruded alginate coatings containing no extra additives (A), polyglycerol esters of fatty acids (EA), or pea protein (PA) was assessed as an alternative to collagen casings (C) for the manufacturing of dry-fermented sausages (fuet) with no inoculation of moulds and without a fermentation step (NMNF) and fuet inoculated with Penicillium candidum and fermented (MF).Stuffing into collagen casings resulted in slower sausage drying kinetics compared with alginate coating. No significant differences in aw were observed among the studied casing types for NMNF and MF fuets and for the evolution of the technological and spoilage microorganisms. Fuets coated with A, EA, and PA showed lower pH values than fuets stuffed in collagen casings. No significant differences on sensory properties between casing types were observed. Therefore, alginate coatings would be a feasible alternative to collagen casing from a technological and safety point of view.

Technological Characterisation of Probiotic Lactic Acid Bacteria as Starter Cultures for Dry Fermented Sausages.

The objective of this study was to investigate probiotic microorganisms for use as starter cultures in dry fermented sausages production. A total of eight strains were studied evaluating technological and safety characteristics including the ability to grow, lactic acid production, gas formation, catalase activity, nitrate reductase activity, proteolytic activity, lipolytic activity, hydrogen peroxide production, salt tolerance, performance at low temperatures, decarboxylation of amino acids and antimicrobial activity against pathogens associated with the product. Lactobacillus rhamnosus R0011, L. rhamnosus Lr-32, Lactobacillus paracasei Lpc-37, Lactobacillus casei Shirota and Enterococcus faecium MXVK29 were good candidates for use as fermented sausages starters cultures because they showed the best technological and safety properties since they did not demonstrate amino acid decarboxylation but showed antimicrobial activity against Listeria monocytogenes, Escherichia coli, Salmonella Dublin and Staphylococcus aureus. L. rhamnosus Lr-32 was the strain best tolerating the levels of salt, nitrate and low pH during the simulated stages of fermentation and ripening of sausage. The strain was thus the most promising of the tested probiotics as sausage starter culture. The findings warrant studies in a meat matrix, such as that of raw-cured sausage, to evaluate the effects of L. rhamnosus Lr-32 under actual conditions.

Rheological and mechanical properties of alginate gels and films containing different chelators

The application of co-extruded calcium alginate casings is becoming more and more popular for the production of dry fermented sausages with small caliber. However, the formation of white efflorescence in coextruded sausages is a substantial problem for manufacturers. Previous studies had shown though that addition of chelators can inhibit formation of efflorescences in non-coextruded sausages. Effect of addition of such compounds to alginate gels used for formation of casings in the co-extrusion technology is yet unknown. Therefore, the influence of calcium chloride (crosslinking solution) and various chelators on the properties of the alginate gels and casings were investigated. The study showed that the influence of increasing concentrations of CaCl2 in the crosslinking solution is of minor importance for the stability of the casings. However, depending on the chelator the stability was either increased, decreased or the same as the control. The addition of citrate did not change the properties, the addition of the polyphosphate P69 significantly increased (p < 0.05) the tensile strength and elastic modulus by 20.84% and 66.54%, respectively. Whereas, the addition of citric acid (68.05% and 63.10%) and the mixture of di- and polyphosphate TARI S78 (26.16% and 13.65%) significantly decreased (p < 0.05) the tensile strength and elastic modulus of the casing. The study showed that the influence of chelators on the alginate gel have to be investigated before the application and furthermore the strengthening could lead to new applications of the casings.

Эффективность использования антиокислителей при производстве ферментированных колбас

Эффективность использования антиокислителей при производстве ферментированных колбас

Survival of Mycobacterium avium subsp. paratuberculosis in raw fermented sausages during production and storage

Mycobacterium avium subsp. paratuberculosis (MAP), the etiological agent of paratuberculosis, is considered to be a potential zoonotic pathogen and meat is one of the sources of MAP exposure for humans. MAP has been shown to be relatively resistant to different food processing methods, but there is a lack of information about the effects of ripening and fermentation processes on MAP survival in meat. Our results demonstrate that a short ripening process during teewurst production did not reduce MAP counts and viable mycobacteria were detected even during 4 weeks of storage. Although no viable MAP was recovered during the dry fermented sausage production process, there was no reduction in MAP count detected by real time PCR during production and storage of both sausages. Although the impact of foodborne exposure to viable MAP and/or mycobacterial components has not yet been clearly determined, the consumption of raw fermented meat products may be considered as a possible route of MAP transmission to humans.

Effect of inoculating Lactobacillus pentosus R3 on N-nitrosamines and bacterial communities in dry fermented sausages

We investigated the effects of Lactobacillus pentosus inoculation on N-nitrosamines (NAs) contents and bacterial communities in dry fermented sausages. Culture-dependent and culture-independent (high-throughput sequencing) methods were employed to evaluate the bacterial communities. The results showed that inoculation with L. pentosus improved the microbiological quality of dry fermented sausages by enhancing the competitiveness of dominant bacteria and inhibiting the growth of undesirable microbes. At the end of ripening, NA content, nitrite residue, carbonyl content, total volatile basic nitrogen, pH value, and water activity of the sausages inoculated with L. pentosus were lower than the control (p < 0.05). L. pentosus showed nitrite depletion ability in Mann–Rogosa–Sharp broth. The bacteria obtained from L. pentosus-inoculated sausages significantly degraded NAs in phosphate-buffered saline (p < 0.05). Thus, L. pentosus can reduce NA levels in dry fermented sausages directly by degrading NAs and indirectly by decreasing their precursors (nitrite, amines) or inhibiting NA formation under conditions of lower pH and water activity, which may be attributed to the higher microbiological quality. Thus, L. pentosus is a potential starter culture for improving safety in the production of dry fermented sausages.

Combination of essential oil compounds and phenolic acids against Escherichia coli O157:H7 in vitro and in dry-fermented sausage production

Escherichia coli O157:H7 is a foodborne pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome. The low dose of infection and severity of the disease represent a concern to public health. Natural compounds have been widely applied as food additives to replace synthetic preservatives. The aim of this study was to determine the efficiency of essential oil compounds (EOCs) in combination with phenolic acids (PA) in vitro and in dry-fermented sausage production. Minimum Inhibitory Concentration (MIC) and Fractional Inhibitory Concentration index (FICindex) were determined for a 5-strain mixture of E. coli O157:H7. Batches of sausage tainted with E. coli O157:H7 were produced using Pediococcus pentosaceus UM 116P and Staphylococcus carnosus UM 123M as starter cultures. The best combination of EOCs and PAs found in vitro was used as an additive. Chemical–physical and microbiological analyses were evaluated weekly from day 0 to 35 after production. Sensory evaluation (texture, odor, flavor, appearance and overall evaluation) of E. coli-free sausages was conducted using a 9-point hedonic scale with 56 untrained volunteers. The MIC values of allyl isothiocyanate (AITC), carvacrol (CAR), ferulic acid (FA), o-coumaric acid (CA) and p-hydroxybenzoic acid (AHB) were, respectively, 0.25; 1.3; 5.12; 18.27; and 37mM. AITC combined with CA had a synergistic effect (FICindex=0.25) and together they were applied in the production of dry fermented sausage at concentrations of 10× FIC and 20× FIC. Aw had no significant difference among treatments, whereas the pH of 10× FIC and 20× FIC were higher than the control. E. coli O157:H7 was reduced by >5logCFU/g with 20× FIC after 21d, and by 2.8logCFU/g with 10× FIC after 35d. Sensory analysis showed that the combination of AITC and ο-coumaric acid in both treatments presented lower scores in the 5 categories when compared to the control, but none of the parameters received a negative score. This study demonstrated that the combination of AITC and ο-coumaric acid at 20× FIC reduced E. coli O157:H7 in compliance with the North American legislation, but adjustments in the dose are necessary to improve the sensory characteristics of the final product.

Moulds and mycotoxins detected in the regional speciality fermented sausage ‘slavonski kulen’ during a 1-year production period

ABSTRACTThis study investigated the surface-to-interior mycotoxin contamination of the regional speciality meat product ‘slavonski kulen’ that occurred during a 12-month period and identified moulds present on its surface during the final production stage. In total, 15 pieces of slavonski kulen were produced and sampled at production months 0, 3, 6, 9 and 12 (three samples per piece). Concentrations of aflatoxin B1 (AFB1) and ochratoxin A (OTA) were determined using the ELISA method, while the identification of moulds made use of both traditional and molecular methods. A 12-month-long production of dry-fermented sausages under controlled conditions that did not include product cleaning at any point caused significant mycotoxin contamination, with determined mean AFB1 and OTA concentrations of 11.79 ± 2.34 and 16.13 ± 3.32 µg kg–1, respectively. Significantly higher mycotoxin levels were observed in the external layers of the products in comparison with their interior and, even more so, central parts. In total, five Penicillium species (P. polonicum, P. terrigenum, P. solitum, P. jugoslavicum and P. corylophilum) and two Aspergillus species (A. versicolor and A. sydowii) were isolated. Moulds responsible for the production of AFB1 and OTA in the later production stages had probably been overgrown by non-toxicogenic moulds, so that the former did not last until the end of the sausages’ production process and were therefore not identified.

LACTIC ACID BACTERIA AND THEIR ROLE IN THE MEAT PROCESSING

Abstract Lactic acid bacteria (LAB) play in meat processing a positive but also a negative role. The principal advantage of LAB in the production of dry fermented sausages lies in the fermentation of saccharides, i.e. the creation of lactic acid and the subsequent fall in pH. The role of LAB in fresh meat spoilage is still controversial. Several species are able to dominate the meat system in VP and MAP storage conditions and can release odor-impact molecules. On the other hand they can provide favorable antagonistic activity against other undesired microorganisms. LAB are important spoilage agents in cooked meat products.

Formation of naturally occurring pigments during the production of nitrite-free dry fermented sausages

This study investigates the potential of producing red coloured dry fermented sausages without the addition of nitrite and/or nitrate. Therefore, the formation of zinc protoporphyrin IX (Zn(II)PPIX) as naturally occurring pigment, and the interrelated protoporphyrin IX (PPIX) and heme content were evaluated during nitrite-free dry fermented sausage production at different pH conditions. Zn(II)PPIX was only able to form in dry fermented sausages at pH conditions higher than approximately 4.9. Additionally, the presence of Zn(II)PPIX increased drastically at the later phase of the production process (up to day 177), confirming that in addition to pH, time is also a crucial factor for its formation. Similarly, PPIX also accumulated in the meat products at increased pH conditions and production times. In contrast, a breakdown of heme was observed. This breakdown was more gradual and independent of pH and showed no clear relationship with the formed amounts of Zn(II)PPIX and PPIX. A statistically significant relationship between Zn(II)PPIX formation and product redness was established.

Influence of various pork fat types on the ripening and characteristics of dry fermented sausage

The influence of three types of pork adipose tissue (neck, back, and leg) on the quality of dry fermented sausages was evaluated. No statistically significant differences between the most abundantly represented methyl esters of fatty acids (FA), such as C16:0, C18:0 and C18:1n-9, were found when the individual FA compositions of the pork adipose tissue samples were compared. The content of polyunsaturated FA was the highest in the neck adipose tissue and the lowest in the leg adipose tissue. These differences were not, however, statistically significant. No differences between the adipose tissue types were found in the sensory, colour, and textural properties, the population of lactic acid bacteria, and the lactic and acetic acids contents in the final products and during the fermentation process. The assertions were not confirmed that pork neck adipose tissue is the best fat type for the production of dry fermented sausages or that pork adipose tissue from the legs is unsuitable because of its insufficient hardness.

Evaluation of N-Nitrosopiperidine Formation from Biogenic Amines During the Production of Dry Fermented Sausages

The aim of this study was to determine the role of the precursors cadaverine (CAD) and piperidine in N-nitrosopiperidine (NPIP) formation during the production of dry fermented sausages. The influences of pH (4.9 and 5.3), sodium nitrite (0 and 150 mg/kg), and ascorbate (0 and 500 mg/kg) were investigated by the use of a dry fermented sausage model. The biogenic amines and volatile N-nitrosamines were analyzed by HPLC-UV and GC-TEA. The major biogenic amines were tyramine, putrescine, and CAD, but their accumulation could be inhibited by NaNO2. When no amine precursors were artificially added, no meaningful N-nitrosamine contamination was observed. The artificial addition of 500 mg/kg cadaverine dihydrochloride (CAD·2HCl) could not provoke increased N-nitrosamine formation. In contrast, the addition of PIP (10 and 100 mg/kg) resulted in higher NPIP concentrations. No influence of pH was observed, but the NPIP formation was more pronounced when NaNO2 was added and sodium ascorbate was excluded from the formulation. The role of ascorbate as N-nitrosamine scavenger was only detectable during the early stage of production. In the end products, NPIP was degraded and the levels were no longer influenced by the initial addition of NaNO2 or ascorbate.

Control of Listeria monocytogenes growth by bacteriocin-producing starter cultures in the manufacturing of dry fermented sausage

The production of dry fermented sausages started as a home-made process, but large-scale industrial manufacture of these products has encountered some safety issues. Although these products present extended shelf-life and offer various hurdles against the growth of undesired organisms, pathogens such as Listeria monocytogenes were found to survive. Bacteriocins have been proposed to act as an extra barrier against the growth of Gram-positive bacteria, including L. monocytogenes. These antimicrobials are synthesized by some lactic acid bacteria (LAB), which are responsible for the fermentation of dry sausages. Many bacteriocins produced by LAB showed ability to inhibitL. monocytogenes growth (e.g. enterocin, pediocin and sakacin). However, the levels of bacteriocins needed to produce this effect in food systems are much higher than those necessary in vitro. Use of bacteriocinogenic starter cultures have shown promising anti-listerial activity in dry sausage, since the antimicrobials are produced in situ confering a better distribution and sustained synthesis throughout the fermentation period. This manuscript reviews the technological challenges of bacteriocin application in dry fermented sausage and the recent findings on using bacteriocinogenic autochtonous LAB to improve safety towards L. monocytogenes. Key words: Fermented sausages, Listeria monocytogenes, bacteriocins

Influence of reduced sodium chloride content on the fermentation and quality of dry fermented sausages

Production of dry fermented sausages is mostly based on local customs and traditional ways of manufacturing. However, in recent decades, these sausages are increasingly produced in industrial conditions, and there is a need to establish the manufacturing procedures, in order to ensure uniformity of the product, and its safety. During the drying of sausages, various changes occur in the sausage stuffing under the influence of water loss and enzymatic degradation of proteins and fats by the action of endogenous (enzymes present in the meat and fat) and exogenous enzymes (enzymes derived from microorganisms). These processes cause the product to obtain the specific, typical sensory properties and longer viability. Microorganisms which are usually responsible for the fermentation process which takes place in the sausages are lactic acid bacteria, and in addition to them coagulase-negative cocci and yeast. Coagulase-negative cocci, with their fermentative activity, contribute to the formation of desirable sensory characteristics of fermented sausages, and lactic acid bacteria contribute to lowering pH value of the stuffing. In the development of new products, such as fermented dry sausages with a reduced content of sodium chloride and fat, there are considerable difficulties because the two components are playing a very important role in the taste of the final product. Sodium chloride has the greatest significance for the taste of the final product, i.e. for its saltiness/savoury quality. Also, it is very important in achieving the microbiological stability of the sausages, because during manufacture they are not subject to heat treatment. The lowest limit of sodium chloride content, according to some data, is 2.5 %, particularly in case of salami. With a lower content of sodium chloride, the products are not hard enough, and are difficult to cut, which is one of the main characteristics of this group of sausages. In order to reduce the salt content in the fermented sausages, the chloride salts of potassium, magnesium and calcium are used as the substituent of sodium chloride. In most developed countries, about 80 % of the salt is originated from food. According to the actuality of this topic, manufacturers are initiating a program of salt reduction in production, and they are starting with the reformulation of their products. Many countries have developed their own guidelines for salt intake program. WHO started the strategy of reduction of salt through the Regional Directorate, and the 11 EU countries signed the program of reduction salt content by 16% over the next 4 years.

Shiga toxigenic Escherichia coli show strain dependent reductions under dry-fermented sausage production and post-processing conditions

Dry-fermented sausages (DFS) are considered possible risk products regarding Shiga toxigenic Escherichia coli (STEC). We have compared the reduction of 11 E. coli isolates of various serogroups in salami during the sausage production process and during post-process measures including storage, heating and freezing. The 11 E. coli isolates, mainly STEC, included enterohaemorrhagic E. coli (EHEC) outbreak strains linked to DFS along with apathogenic E. coli. During sausage production, there was a statistically significant difference in reduction between the E. coli strains ranging from 1.3 to 2.4 log10 (p<0.001). When sausages were subjected to post-process heat treatment of 43°C for 24h, a total reduction of more than 5 log10 was obtained for all E. coli isolates. Freezing and thawing of DFS with subsequent storage for 1month at 16 or 20°C generally contributed to large E. coli reductions with the latter conditions giving an average additional 3.9 log10 reduction, with a range from 3.4 to 4.4 log10. The combination of freezing and 1month of storage gave higher reductions compared with storage for 2months for all examined temperatures. No systematic differences in survival of E. coli of different serogroups were detected for the different post-process measures. The reductions were also similar to those of apathogenic control isolates. Isolates showing higher survival during the ripening process did not have a lower reduction when exposed to post-process stress like storage, heating and freezing. The ability of the isolates to survive in salami was also compared with their survival at equivalent conditions in a tryptic soy broth (TSB) model. There was a low and not significant correlation (p>0.1) between the reductions of E. coli in salami and in the TSB broth model. Results based on broth models and/or single or surrogate strains must therefore be interpreted with caution. The EHEC reducing post-processing measures tested can easily be implemented in DFS production with marginal influence on the quality of the sausages.

Metabolism of amino acids, dipeptides and tetrapeptides by Lactobacillus sakei

The microbial degradation of proteins, peptides and amino acids generates volatiles involved in the typical flavor of dry fermented sausage. The ability of three Lactobacillus sakei strains to form aroma compounds was investigated. Whole resting cells were fermented in phosphate buffer with equimolar amounts of substrates consisting of dipeptides, tetrapeptides and free amino acids, respectively. Dipeptides disappeared quickly from the solutions whereas tetrapeptides were only partially degraded. In both approaches the concentration of free amino acids increased in the reaction mixture but did not reach the equimolar amount of the initial substrates. When free amino acids were fed to the bacteria their levels decreased only slightly. Although peptides were more rapidly degraded and/or transported into the cells, free amino acids produced higher amounts of volatiles. It is suggested, that after transport into the cell peptides are only partially hydrolyzed to their amino acids, while the rest is metabolized via alternative metabolic pathways. The three L. sakei strains differed to some extend in their ability to metabolize the substrates to volatile compounds. In a few cases this was due to the position of the amino acids within the peptides. Compared to other starter cultures used for the production of dry fermented sausages, the metabolic impact of the L. sakei strains on the formation of volatiles was very low.