Accumulation Of Biogenic Amines Research Articles

Primary and Secondary Succession Mediate the Accumulation of Biogenic Amines during Industrial Semidry Chinese Rice Wine Fermentation.

The use of exogenous functional microorganisms to regulate biogenic amine (BA) content is a common approach in fermentation systems. Here, to better understand the microbial traits of succession trajectories in resource-based and biotic interference systems, the BA-related primary and secondary succession were tracked during industrial semidry Chinese rice wine (CRW) fermentation. Dominant abundance and BA-associated microbial functionality based on phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) indicated that Citrobacter, Acinetobacter, Lactobacillus, Exiguobacterium, Bacillus, Pseudomonas, and Enterobacter spp. prominently contributed to the decarboxylase gene family in CRW. The expression levels of tyrosine decarboxylase (tyrDC), ornithine decarboxylase (odc), and agmatine deiminase (aguA) genes were assessed by quantitative PCR (qPCR). The transcription levels of these genes did not correlate with the BA formation rate during postfermentation, indicating that acidification and carbon source depletion upregulated the expression and microbes launch the dormancy strategy to respond to unfavorable conditions. Furthermore, microbial interference with CRW fermentation by Lactobacillus plantarum (ACBC271) and Staphylococcus xylosus (CGMCC1.8382) coinoculated at a ratio of 1:2 exhibited the best synergetic control of BA content. Spearman correlations revealed that Lactobacillus and Staphylococcus exhibited influence on BA-associated microbiota (|ρ| > 0), Exiguobacterium and Pseudomonas were strongly suppressed by Lactobacillus (ρ = -0.867 and ρ = -0.782, respectively; P < 0.05), and Staphylococcus showed the strongest inhibitory effect toward Lactobacillus (ρ = -0.115) and Citrobacter (ρ = -0.188) in the coinoculated 1:2 group. The high inhibitory effect of exogenous added strains on specific bacteria presented evidence for the obtained BA-associated contributors. Overall, this work provides important insight into the microbial traits that rely on resource usage and functional microbiota within food microbial ecology.IMPORTANCE Understanding the shifting patterns of substance usage and microbial interactions is a fundamental objective within microbiology and ecology. Analyses of primary and secondary microbial succession allow for determinations of taxonomic diversity, community traits, and functional transformations over time or after a disturbance. The kinetics of BA generation and the patterns of resource consumption, functional metagenome prediction, and microbial interactions were profiled to elucidate the equilibrium mechanism of microbial systems. Secondary succession after a disturbance triggers a change in resource usage, which in turn affects primary succession and metabolism. In this study, the functional potential of exogenous microorganisms under disturbance synergized with secondary succession strategies, including rebalancing and dormancy, which ultimately reduced BA accumulation. Thus, this succession system could facilitate the settling of essential issues with respect to microbial traits that rely on resource usage and microbial interactions that occur in natural ecosystems.

Aminas biógenas en alimentos: métodos moleculares para la detección e identificación de bacterias productoras

Las aminas biógenas son compuestos nitrogenados de pequeño tamaño con actividad biológica que se forman por la descarboxilación enzimática de ciertos aminoácidos. Las aminas biógenas se encuentran presentes en todos los seres vivos, en los que participan en procesos biológicas de gran importancia. Sin em­bargo, debido al metabolismo de algunos microorganismos, estos compuestos se pueden acumular en alimentos en concentraciones elevadas, constituyendo un riesgo para la salud de los consumido­res. Para que las aminas biógenas alcancen estas concentraciones elevadas en los alimentos se requiere, como condición indispensa­ble, la presencia de microrganismos productores, por lo que se han desarrollado diferentes métodos para detectar la presencia de los mismos. Entre estos métodos, aquellos basados en técnicas inde­pendientes de cultivo, como la PCR, presentan ventajas como su gran especificidad, el hecho de ser rápidos y de fácil realización, y que en muchos casos ni siquiera es necesario un tratamiento previo de la muestra, lo que facilita su incorporación a las plantas de elabo­ración. En este trabajo se describen algunos de los métodos dispo­nibles en la actualidad para la detección de microorganismos pro­ductores de aminas biógenas, así como sus posibles aplicaciones.

The overall structure of microbiota in patients with adenocarcinoma stomach and colon cancer

IntroductionAccumulating evidence suggests that the human bowel microbiota contributes to the etiology of colorectal cancer (CRC) and stomach cancer, not only via the pro-carcinogenic activities of specific pathogens but also via the influence of the wider microbial community, particularly its metabolome.The aim of the studyThe aim of this study was to analyzes the overall structure of microbiota in patients with adenocarcinoma of colorectal and the stomach and healthy controls.ResultsThe studies suggested that colorectal cancer and stomach cancer develops from the complex interactions between inherited susceptibility and environmental factors, there a strong association between adenomatous polyps and some pathogenic bacteria are the precursors of the vast majority of colorectal cancers and stomach. Thus, the data suggested the development of intestinal dysbiosis in patients with adenocarcinoma, which was characterized by inhibiting obligate protective microflora and activation opportunistic microorganisms on the base of carbohydrates, fats, and proteins metabolism disturbances and accumulation of toxic metabolic products that may be an important pathogenetic factor of tumor tissue activation, induction, proliferation, and metaplasia. Significant accumulation of biogenic amines (methylamine, serotonin, histamine) is a leading metabolic profile of microflora inpatient with adenocarcinoma and may have a predictive value for diagnosis, pathogenetic therapy, and determination of food nutrients role in the mechanisms of cancer formation, as well as identifying populations of cancer risk.ConclusionsThe composition of the tumor microbiome differed from that of adjacent non-neoplastic tissue. The subsite-specific alterations in the colorectal carcinoma and stomach cancer microbiota. There is a high incidence of colorectal cancer and stomach cancer associated with Streptococcus Bovis. These results suggested that the mucosa-associated microbiota is dynamically associated with colorectal carcinoma, which may provide evidence for microbiota-associated diagnostic, prognostic, preventive, and therapeutic strategies for colorectal carcinoma and stomach cancer.

Effects of spices on the formation of biogenic amines during the fermentation of dry fermented mutton sausage

A precise and unambiguous quantitative strategy for six biogenic amines in dry fermented mutton sausage with liquid chromatography tandem quadrupole Orbitrap mass spectrometry was developed to investigate the inhibitory effects of star anise, amomum tsao-ko, clove, cassia, fennel, bay leaf, and nutmeg on the accumulation of biogenic amines. Compared the data-dependent MS2 fragmentation (dd-MS2), variable data-independent acquisition (vDIA), and multiplex data-independent acquisition (mDIA), and the mDIA acquisition mode was selected for further analysis. The LODs and LOQs were 0.9–1.5 μg kg−1 and 2.9–5.0 μg kg−1. The maximum inhibition of spice on tryptamine, putrescine, spermidine, 2-phenylethylamine, tyrosamine, and histamine were 21.8%, 19.3%, 27.5%, 24.6%, 18.7% and 24.4%, which revealed that the accumulation of BAs was significantly inhibited by spice extracts, while cassia and fennel extracts showed the best effect. Thus, the established method can provide a better reference for dry fermented mutton sausage quality, safety and trade analysis.

Biogenic amines content in Fiore Sardo cheese in relation to free amino acids and physicochemical characteristics.

Fiore Sardo is a Protected Designation of Origin (PDO) cheese produced in Sardinia (Italy) from raw sheep’s milk, presenting risk factors due to an accumulation of Biogenic Amines (BA). A total of 37 Fiore Sardo cheese samples produced in 19 dairy farms were collected from local retail stores to evaluate BA content and its relationship with free amino acids (FAA) and composition. The following were determined for each sample: pH, water activity, composition (moisture, dry matter, NaCl, protein and fat content). FAA and BA, after extraction, were determined by HPLC-FL. The total BA content in Fiore Sardo PDO cheese samples was 127±87 mg 100 g-1, ranging between 6 and 366 mg 100 g-1. Tyramine showed the highest concentration (82±51 mg 100 g-1), followed by putrescine (21±26 mg 100 g-1). Moreover, cadaverine, histamine, β-phenylethylamine and tryptamine were detected at concentrations lower than 10 mg 100 g-1. Overall 54% of the samples analysed exceeded the threshold of 90 mg 100 g-1 for total BA content, posing a potential risk for consumers. BA, total FAA (2233±764 mg 100 g-1) and pH were positively correlated (P≤0.01) between themselves, whereas BA content was not correlated with aw, humidity and percentage of NaCl. The hierarchical cluster analysis results, considering 37 samples and 6 variables, detected four different groups. Samples with BA ≥200 mg 100 g-1 were distributed in two groups characterized by a higher proteolysis indicator levels (FAA, pH) but significantly different for aw, humidity and NaCl concentration. The results showed that high levels of BA were detectable in some samples of Fiore Sardo PDO cheese, suggesting that effective technological conditions at production should be adopted.

Isolation of biogenic amine-negative lactic acid bacteria for Chinese rice wine fermentation based on molecular marker reverse screening.

Chinese rice wine (CRW; a traditional alcoholic beverage in China with unique flavor and high nutritional value) containing high level of biogenic amines (BAs) may be deleterious to human health. The processes of rice soaking, primary fermentation and secondary fermentation were found to be the major factors for accumulation of BAs during industrial CRW production. To reduce the risk of the formation of BAs in CRW production, Enterococcus durans AR315, a BA-negative lactic acid bacterium, was isolated from CRW samples by PCR-based molecular marker reverse screening in this work. With addition of AR315 during steeping rice phase, the level of total BAs was significantly decreased by 45.1% in comparison with the control. Moreover, the final BA concentration with the addition of AR315 was 27.6% lower than that of the control during fermentation phase. To our knowledge, this is the first report of decreased accumulation of BAs in CRW production using a BA-negative lactic acid bacterium. Hence, using a BA-negative lactic acid bacterium as a starter culture could be an efficient strategy for significantly reducing the formation of BAs, which has the potential for industrial application in CRW production. © 2020 Society of Chemical Industry.

Effects of starter cultures on lipid oxidation and accumulation of biogenic amines in traditional Chinese smoked horsemeat sausage

This study evaluated the effects of starter cultures (Lactobacillus sakei and Staphylococcus xylosus) on lipid oxidation and accumulation of biogenic amines (BAs) in Chinese smoked horsemeat sausage. Physicochemical parameters, microorganisms, and sensory properties were assessed in smoked horsemeat sausage. Traditional microbiological detection and polymerase chain reaction-denaturing gradient gel electrophoresis analysis showed that the starter cultures inhibited the growth of pathogenic bacteria in smoked horsemeat sausage during ripening. In addition, the starter cultures not only significantly reduced lipid oxidation, but also inhibited the accumulation of BAs (cadaverine, tyramine, putrescine, 2-phenylethylamine, histamine, and tryptamine) in smoked horsemeat sausage. Sensory evaluation results showed that the starter cultures significantly improved the color, taste, odor, and overall acceptability scores of the smoked horsemeat sausage. Overall, the starter cultures were suitable for production of smoked horsemeat sausage with good organoleptic qualities. Practical applications In China, smoked horsemeat sausage is one of the most popular traditional fermented sausage with a long history, but it is difficult to control quality during product fermentation. However, to the best of our knowledge, few studies exist on the effect of mixed starter cultures on smoked horsemeat sausage. This study strongly evidenced that the mixed starter cultures (Lactobacillus sakei and Staphylococcus xylosus) can significantly inhibit lipid oxidation and the accumulation of BAs in smoked horsemeat sausage, thereby improving product quality.

Modifications of Phenolic Compounds, Biogenic Amines, and Volatile Compounds in Cabernet Gernishct Wine through Malolactic Fermentation by Lactobacillus plantarum and Oenococcus oeni

Malolactic fermentation is a vital red wine-making process to enhance the sensory quality. The objective of this study is to elucidate the starter cultures’ role in modifying phenolic compounds, biogenic amines, and volatile compounds after red wine malolactic fermentation. We initiated the malolactic fermentation in Cabernet Gernishct wine by using two Oenococcus oeni and two Lactobacillus plantarum strains. Results showed that after malolactic fermentation, wines experienced a content decrease of total flavanols and total flavonols, accompanied by the accumulation of phenolic acids. The Lactobacillus plantarum strains, compared to Oenococcus oeni, exhibited a prevention against the accumulation of biogenic amines. The malolactic fermentation increased the total esters and modified the aromatic features compared to the unfermented wine. The Lactobacillus plantarum strains retained more aromas than the Oenococcus oeni strains did. Principal component analysis revealed that different strains could distinctly alter the wine characteristics being investigated in this study. These indicated that Lactobacillus plantarum could serve as a better alternative starter for conducting red wine malolactic fermentation.

Biogenic amines formation and their importance in fermented foods

Biogenic amines (BAs) are low molecular weight organic bases with an aliphatic, aromatic, or heterocyclic structure which have been found in many foods. biogenic amines have been related with several outbreaks of food-borne intoxication and are very important in public health concern because of their potential toxic effects. The accumulation of biogenic amines in foods is mainly due to the presence of bacteria able to decarboxylate certain amino acids. Biogenic amines are formed when the alpha carboxvl group breaks away from free amino acid precursors. They are colled after the amino acid they originated from. The main biogenic amines producers in foods are Gram positive bacteria and cheese is among the most commonly implicated foods associated with biogenic amines poisoning. The consumption of foods containing high concentrations of biogenic amines has been associated with health hazards and they are used as a quality indicator that shows the degree of spoilage, use of non-hygienic raw material and poor manufacturing practice. Biogenic amines may also be considered as carcinogens because they are able to react with nitrites to form potentially carcinogenic nitrosamines. Generally, biogenic amines in foods can be controlled by strict use of good hygiene in both raw material and manufacturing environments with corresponding inhibition of spoiling microorganisms. The aim of this review was to give some information about biogenic amines in foods.

Biogenic amine content during the production and ripening of Sremski kulen, Serbian traditional dry fermented sausage.

Sremski kulen is a wide diameter dry fermented sausage, produced from pork, seasoned with red spicy paprika, stuffed into pork cecum, and preserved by smoking, fermentation and drying. Due to specific ripening process, Sremski kulen is suitable for the accumulation of biogenic amines. Therefore, the aminogenesis was studied in traditionally produced Sremski kulen, taking into account the physicochemical parameters and microbial counts. The content of six biogenic amines (tryptamine, phenylethylamine, tyramine, histamine, putrescine, and cadaverine) was analyzed using high-performance liquid chromatography. The ripening process of Sremski kulen was slow followed by changes in aw and pH value as well as expressed proteolysis. The autochthonous microbiota showed pronounced decarboxylase activity. Tryptamine and phenylethylamine were detected at each examined ripening stage while histamine was not detected until the end of ripening (16.55±2.33mg/kg). Tyramine, cadaverine, and putrescine content significantly increased during the ripening period (p<.05). In the final product, cadaverine was the dominant biogenic amine (132.40±5.05mg/kg), followed by tyramine (115.80±15.46mg/kg) and putrescine (68.55±2.39mg/kg). Although the long ripening period greatly contributed to the accumulation of biogenic amines in final product, their content are not of concern from product safety aspects, but requires improvement in hygiene of production process.

Application of end-point PCR technique to detect bacteria encoding tyrosine decarboxylase (TDC) gene in scombridae fish

Tuna, little tuna, and skipjack can form tyramine from decarboxylation of tyrosine by tyrosine decarboxylase (TDC) enzyme. High tyramine level in fish could cause toxicological effects. Early detection of the tyramine-forming bacteria by using DNA-based methods is needed for seafood safety assurance because it is more sensitive, specific, and faster. This study was aimed to obtain bacterial isolates, detection of TDC and 16S rRNA genes and identifying species of bacteria that encode TDC and 16S rRNA genes. The methods of this study included several steps including bacterial cultivation, DNA isolation and amplification of TDC and 16S rRNA gene markers as well as sequencing of amplicons. Bacterial DNA isolates were successfully obtained from samples by cultivation method. The TDC gene was successfully amplified and identified as belong to Carnobacterium genus, whereas the 16S rRNA gene belong to Enterobacter tabaci, E. hormaechei, Escherichia marmotae, and Peptoniphilus genus. The DNA-based method targeted tyrosine decarboxylase gene can be applied for early detection of biogenic amine accumulation in fishery products.

Isolation, characterization, and application of biogenic amines‐degrading strains from fermented food

AbstractThe aim of the present study was to screen a type of microorganism for degradation of bioamines in fermented food, investigate their characteristics in growth and degrading bioamines, and also assess the effects of inoculating strain starter cultures on biogenic amines (BAs) accumulation in soy sauces. The screening for no‐BAs‐producing strains was carried out using a double color method and an oxidase test. The degradation rates were determined by high‐performance liquid chromatography with fluorescence detection (HPLC‐FLD). In this study, strains (J2 and J3) with high ability were isolated from some naturally fermented food samples. They were identified as Wickerhamomyces anomalus and Millerozyma farinosa, respectively, by partial amplification of the 16S rRNA gene. The strains exhibited high multiple BAs degradation activity over a range of pH values (5–8), temperatures (28–35°C), salt (NaCl) concentrations (0–10%), and ethanol concentrations (0–10%). One of the isolated strains, W. anomalus, has the highest biodegradability for putrescine, cadaverine, histamine, and tyramine with degradation rates of 61, 66, 67, and 59% in an experimental model, and 39.3, 33.6, 39.9, and 43.1% in fermented soy sauce containing 10% of NaCl, respectively. Additionally, the study of mechanism demonstrated that the removal ability of BAs was mainly due to biodegradation.

Effect of taxifolin on physicochemical and microbiological parameters of dry-cured pork sausage

The effect of taxifolin (TXF) with starter cultures (SC), such as Leuconostoc carnosum, or a mixture of strains Pediococcus pentosaceus and Staphylococcus xylosus, on the TXF stability was evaluated. UPLC analysis demonstrated that after 181 days of storage total TXF content was the highest in samples with TXF and L. carnosum (60%), compared to the 1st day of storage. The sausages with TXF and the mixture of P. pentosaceus and S. xylosus (56%) followed next. The samples treated only with TXF retained 40% of TXF, compared to the 1st day of storage. TXF had no significant effect on the growth of lactic acid bacteria. The accumulation of biogenic amines (BA), including histamine and putrescine, was more effectively reduced in sausages inoculated with the TXF plus P. pentosaceus and S. xylosus mixture. Using this mixture, the rate of lipolysis and processes of lipid oxidation were effectively slowed down. Fatty acid (FA) composition was stable in all cases.

Inhibitory effects of safflower and bitter melon extracts on biogenic amine formation by fish spoilage bacteria and food borne pathogens

The impact of safflower (Carthamus tinctorius) and bitter melon (Momordica charantia L.) extracts on growth of fish spoilage bacteria (Acinetobacter lwoffii, Pseudomonas oryzihabitans, Enterobacter cloacae, Shigella spp., Morganella psychrotolerans, Photobacterium phosphoreum) and food-borne pathogens (Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis, Salmonella Paratyphi A) and their biogenic amine formation were investigated in mackerel infusion decarboxylase broth (MIDB). The broth microdilution method was used to test antimicrobial activity of extracts. Ent. faecalis was the most susceptible microorganism with minimum inhibitory concentrations (MIC) of 6.25 mg/mL against safflower extract, whilst bitter melon had the highest inhibitory effect against growth of Ent. cloacae, Shigella spp. and Ent. faecalis with MIC of 12.5 mg/mL. Differences in ammonia (AMN) and biogenic amine (BA) production among groups were statistically significant (p < 0.05). Ent. faecalis (2810 mg/L) was the main tyramine producer in MIDB. Although the effect of extracts varied depending on the bacterial strain and specific amine, both extracts generally decreased AMN and BA accumulation by bacteria. Histamine production by Phot. phosphoreum was considerably suppressed in the presence of extracts (p < 0.05). As a result, safflower and bitter melon extracts could be used as antimicrobial agents to inhibit bacterial growth and their BA formation in food.

How fermentation by lactic acid bacteria can address safety issues in legumes food products?

Fermented Asian foods have recently gained popularity, crossing from Asian communities to mainstream markets, in many western countries. However, less attention has been paid to the safety of these foods. In South-East Asia, fermented products are still produced following traditional methods. Therefore, consumers are not confident in their microbial safety. The challenges awaiting fermentation in South-East Asia are thus to improve safety and quality in a sustainable system producing tasty and typical fermented products. A possible solution could be the use of starter cultures able to increase the safety of food stuffs. Starters could also help to standardize the production process and reduce ripening times. The current review addresses the role of lactic acid bacteria on the microbiological and chemical safety of Asian legume based fermented products. In particular, their role in the reduction of anti nutritional compounds (e.g. phytates) and protein allergenicity is discussed. Moreover, starters can inihibit the development of amino acid-decarboxylating microbes preventing the accumulation of biogenic amines, they can also be useful to reduce the accumulation of mycotoxins and inhibit pathogens’ development. Finally, their role in the degradation of pesticides is analyzed.

The effect of reduction of NaCl content on selected parameters during ripening of cheese

The aim of this work was to observe chemical and physical changes in Dutch-type cheese during ripening depending on salt concentration. Ripening is one of the most important factors influencing the sensory quality of cheese and therefore the cheese production should be studied. Among the substances which are formed during ripening belong the biogenic amines which are produced by the decarboxylation of amino acids. These amino acids are created during proteolysis. The salt content largely affects the intensity of the ripening process, but also other cheese parameters such as dry matter content, hardness or content of biogenic amines. In the course of 3 months ripening of model cheeses with different cultures and with different salt content, the effect of the salt on pH, dry matter content, free amino acids and biogenic amines content and hardness was monitored. The concentration of NaCl affected the dry matter content and the hardness of the samples. The reduction in salt content contributes to the higher accumulation of biogenic amines during ripening.

Accumulation γ-Aminobutyric Acid and Biogenic Amines in a Traditional Raw Milk Ewe's Cheese.

The influence of calf (R1), kid (R2) and pig (R3) rennets on microbiota, biogenic amines (BAs) and γ-aminobutyric acid (GABA) accumulation in raw milk ewe’s cheeses was evaluated. Cheeses were investigated at different ripening times for their microbial composition, free amino acids (FAAs), BAs and GABA content. Moreover, the expression of tyrosine (tdc) and histidine (hdc) decarboxylases genes was evaluated by quantitative Real Time–Polymerase Chain Reaction (qRT-PCR). Microbial counts showed similar values in all samples. Pig rennet were cheeses were characterized by higher proteolysis and the highest values of BAs. The BAs detected were putrescine, cadaverine and tyramine, while histamine was absent. qRT-PCR confirmed this data, in fact hdc gene was not upregulated, while tdc gene expression increased over time in agreement with the increasing content of tyramine and the highest fold changes were detected in R3 cheeses. GABA showed the highest concentration in R2 cheeses reaching a value of 672 mg/kg. These results showed that the accumulation of BAs and GABA in Pecorino di Farindola is influenced by ripening time and type of coagulant. Further studies are required to develop starter cultures to reduce BAs content and improve health characteristics of raw milk ewe’s cheeses.

Evolution of amino acids and biogenic amines in traditional dry-fermented sausage Sjenički sudžuk during processing

The evolution of free amino acids and biogenic amines during 23 days of drying and ripening was determined in the traditional, dry-fermented sausage, Sjenički sudžuk. The concentration of most amino acids increased significantly (P < 0.05) over time, giving rise to a final concentration of total free amino acids of 600 mg/100g dry matter. Thus, the chief precursors became available for indigenous aminogenic microbiota, enabling formation and accumulation of biogenic amines. Total biogenic amines reached the level of 399 mg/kg by day 23 of processing. Putrescine and tyramine were the predominant amines. Their concentrations increased significantly (P < 0.05) during processing, ranging from 91.9 to 212 mg/kg and from 48.5 to 147 mg/kg, respectively. A positive outcome of this study is the very low registered concentration of histamine (9.69 mg/kg), the most important amine both from the toxicological and hygienic points of view.

Evaluation of the Biogenic Amines and Microbial Contribution in Traditional Chinese Sausages.

Biogenic amines (BAs) in sausages represent a health risk for consumers, and thus investigating the BAs accumulation mechanism is important to control the BAs. In this study, the BAs profiles of 16 typical Chinese sausage samples were evaluated, and 8 kinds of common BAs were detected from different samples. As a whole, the BAs contents of the majority of Chinese sausage samples were within the safe dosage range, except that the total BAs and histamine concentrations of sample HBBD were above the toxic dosage levels. Furthermore, the bacterial and fungal communities of the Chinese sausage samples were investigated by high-throughput sequencing analysis, and Staphylococcus, Bacillus, Lactococcus, Lactobacillus, Debaryomyces, and Aspergillus were identified as the predominant genera. Accordingly, 13 representative strains were selected from the dominant genera, and their BAs formation and degradation properties were evaluated. Finally, the results of fermented meats model experiment indicated that the Staphylococcus isolates including Staphylococcus pasteuri Sp, Staphylococcus epidermidis Se, Staphylococcus carnosus Sc1, Staphylococcus carnosus Sc2, and Staphylococcus simulans Ss could significantly reduce BAs, possessing the potential as the starter cultures to control the BAs in fermented meat products. The present study not only helped to explain the BAs accumulation mechanism in Chinese sausage, but also developed the candidates for potential BAs control in fermented meat products.

Role of Starter Cultures on the Safety of Fermented Meat Products.

Starters are microbial cultures used to promote and conduct the fermentation of meat products. Bacteria, particularly lactic acid bacteria (LAB) and coagulase-negative staphylococci (CNS), as well as yeasts and molds, may be used as starters. They can increase the safety of fermented meat products by means of rapid matrix acidification or due to the production of antimicrobial substances, such as bacteriocins. Besides, starters may help to standardize product properties and shorten ripening times. Safety of fermented meat products may be jeopardized by microbiological, namely foodborne pathogens (Salmonella spp., Listeria spp., etc), and chemical hazards, particularly biogenic amines, nitrosamines, polycyclic aromatic hydrocarbons (PAH), and mycotoxins. Biogenic amines (BA) are potentially unsafe nitrogenous compounds that result from the decarboxylation of some amino acids. Some microorganisms may be responsible for their formation. Starters can cause a fast pH decrease, inhibiting the development of microorganisms with amino acid decarboxylative ability, thus preventing the accumulation of BA in fermented meat products. Besides, starters can compete with the autochthonous, non-starter microbiota throughout ripening and storage, thus reducing BA production. Some strains of Lactobacillus sakei and Lactobacillus plantarum have been shown to reduce the formation/accumulation of BA. On the other hand, Staphylococcus xylosus and Debaryomyces hansenii strains have been reported to degrade BA in food. PAH are organic compounds containing multiple aromatic rings and produced by the incomplete combustion of organic matter, such as the wood used for smoking meat. Mixed starters containing Lactobacillus spp., Gram-positive catalase-positive cocci and yeasts have been used in the manufacturing of traditional meat sausages. However, the effect of starters on reducing the accumulation of PAH is poorly understood. Starters may also be engaged in competitive exclusion, outcompeting the spoiling or deteriorating autochthonous microbiota. For example, Pediococcus acidilactici has been shown to inhibit Listeria monocytogenes in meat products. Additionally, the role of molds, such as Penicillium nalgiovense, in the competitive exclusion of undesired filamentous fungi, has also been demonstrated. Most of these undesired fungi produce mycotoxins, secondary metabolites capable of causing disease. The current review addresses the role of starters on the microbiological and chemical safety of fermented meat products.