Effects of Lactobacillus plantarum and Staphylococcus xylosus on the Quality Characteristics of Dry Fermented Sausage "Sucuk"

ABSTRACT:  The effect of starter culture, containing the strains Lactobacillus plantarum GM77 and Staphylococcus xylosus GM92, isolated from traditional sucuk, on the quality characteristics of dry fermented sausage (sucuk) during ripening period was studied. The microbiological (lactic acid bacteria, Micrococcus/Staphylococcus , Enterobacteriaceae) and physicochemical (pH, a_w, NPN, TBARS) properties and volatile compounds, extracted by solid phase microextraction and analyzed by gas chromatography-mass spectrometry, were determined in sucuk samples with starter culture and in the control group (without starter culture). Both starter culture and ripening period had significant effects on lactic acid bacteria, Micrococcus/Staphylococcus counts, and pH and a_w values ( P  < 0.01). The highest value for nonprotein nitrogen (NPN) was observed to occur in samples with starter culture ( P  < 0.05). TBARS value increased during ripening, the highest value was determined at 14th day in samples with starter culture. Among volatile compounds, terpenes were the major group in sucuk. Other volatile compounds (aldehydes, ketones, sulfur compounds, acids, esters, aliphatic hydrocarbons, aromatic hydrocarbons, and alcohols) can be found in fewer amounts. While the use of starter culture was affecting a few compounds, ripening period had affected most of the compounds.     

The effects of a starter culture on the formation of biogenic amines in Turkish soudjoucks

The effects of starter culture containing Lactobacillus sake, Pediococcus pentosaceus, Staphylococcus carnosus plus Staphylococcus xylosus on the formation of biogenic amines during ripening of Turkish soudjoucks were investigated. Determination of eight different biogenic amines was carried out by reverse-phase high performance liquid chromatography (HPLC) using diode array detection. It was found that aerobic plate counts (APC) decreased in the samples with added starter culture. Lactic acid bacteria counts increased in both the controls and samples with added starter during ripening. Total Enterobacteriaceae (ENT) counts decreased on the 30th day for vacuum packed and starter added samples. Yeast counts decreased only in vacuum packed and starter added samples on the 30th day. No biogenic amines were found in ground meat samples. Putrescine (PU) and tyramine (TYR) were determined in all control samples during the storage at 4°C. Starter addition inhibited formation of PU but not TYR.     

Effects of starter cultures and additives on the quality of Turkish style sausage (sucuk)

The effects of starter cultures and additives on the quality of Turkish style sausage (sucuk) were investigated during ripening and storage. Total aerobic plate counts (aerobic bacteria), mould and yeast counts, pH, thiobarbituric acid (TBA) value and biogenic amine formation were followed. Aerobic bacteria increased (P<0.05) during the first 10 days of ripening to 9.26 log CFU/g and they decreased (P<0.05) to 5.70 at the end of the storage. Larger reductions (P<0.05) were observed in sausages made with high levels of potassium sorbate, nitrite and nitrate than in those containing low levels of additives and those without additives at the end of storage. During the first 3 days of ripening, the pH values of all sausages decreased (P<0.05) from 5.98 to about 4.53. Later, the pH values increased slowly, due to decomposition of acids to an approximately constant value of about 5.20. TBA values were higher (P<0.05) in the sausages made without additives than in the others. Sausages prepared using high concentration of additives had lower (P<0.05) concentrations of biogenic amines than the others. Addition of starter culture with high concentration of additives (nitrite, nitrate, α-tocopherol, ascorbic acid, potassium sorbate, potassium pyrophosphate and di-potassium hydrogenphosphate) decreased the formation of biogenic amine.     

Starter cultures and high-pressure processing to improve the hygiene and safety of slightly fermented sausages

The effectiveness of selected starter cultures and high hydrostatic pressure after ripening was evaluated to improve the safety and quality of slightly fermented sausages. Inhibition of common foodborne pathogens, spoilage bacteria, and biogenic amine content was studied. Random amplification of polymorphic DNA and plasmid profiles were used to monitor the competitiveness of the starter cultures during fermentation and ripening. Lactobacillus sakei CTC6626 and Staphylococcus xylosus CTC6013 dominated L. sakei CTC6469 and S. xylosus CTC6169 independently of the product assayed. Starter cultures were able to control the growth of Listeria monocytogenes, Enterobacteriaceae, Enterococcus, and the biogenic amine content. A pH decrease below 5.3 at the seventh day of fermentation was crucial. Salmonella spp. counts decreased significantly during ripening independently of the use of starter culture and product. High hydrostatic pressure treatment was necessary to ensure absence of Salmonella spp. in final products.     

The effect of nitrite and starter culture on microbiological quality of "chorizo"-a Spanish dry cured sausage

The effect of nitrite and starter culture on the survival of Enterobacteriaceae, Micrococcaceae, Lactic acid bacteria and other microorganisms was evaluated during ripening of "chorizo", a Spanish dry sausage. Sodium nitrite 50 and 150 ppm and Lactobacillus sake CL35 added to the "chorizo" have a significant inhibitory effect on Enterobacteriaceae counts but did not on Micrococcaceae. The use of Lact. sake could be an adequate safety factor in this product.     

不同乳酸菌发酵剂对发酵红肠品质的影响

为研究乳酸菌发酵对红肠品质的影响,将发酵技术应用于本无发酵工艺的红肠制品中,筛选出能够提高红肠品质的乳酸菌发酵剂。分别将常应用于发酵肉制品的7 种商业乳酸菌发酵剂（木糖葡萄球菌＋戊糖片球菌（THM-17）、木糖葡萄球菌＋清酒乳杆菌＋类植物乳杆菌（PRO-MIX5）、木糖葡萄球菌＋肉葡萄球菌＋清酒乳杆菌（WBL-45）、木糖葡萄球菌＋戊糖片球菌＋植物乳杆菌（VHI-41）、木糖葡萄球菌＋戊糖片球菌＋植物乳杆菌（SHI-59）、肉葡萄球菌＋木糖葡萄球菌（WBX-43）和戊糖片球菌＋木糖葡萄球菌＋肉葡萄球菌＋乳酸片球菌（VBM-60））及8 种单菌（弯曲乳杆菌、戊糖乳杆菌、清酒乳杆菌-1、戊糖片球菌、木糖葡萄球菌、肉葡萄球菌、清酒乳杆菌-2、植物乳杆菌）以107 CFU/g的接种量接种至腌制后的肉馅中,拌馅灌肠后于35 ℃、80%湿度条件下发酵12 h,取样测定发酵后样品的乳酸菌数和细菌总数,再经干燥、蒸煮、烟熏、烘烤制得成品,测定其感官、pH值、色差、质构、亚硝酸盐、硝酸盐、生物胺及N-亚硝胺含量等指标。结果表明：15 种发酵剂中以木糖葡萄球菌和植物乳杆菌2 种乳酸菌发酵剂应用效果较好,所制得产品pH值分别为5.26和5.04,色泽美观,弹性适中,亚硝酸盐残留量（10.84、10.13 mg/kg）低,可显著抑制N-亚硝胺的形成（N-二甲基亚硝胺含量分别为1.29、2.51 μg/kg）,生物胺总量较低。由此说明,木糖葡萄球菌和植物乳杆菌能够显著提高红肠产品的安全品质。     

Effect of proteolytic starter cultures of Staphylococcus spp. on biogenic amine formation during the ripening of dry fermented sausages

The effect of proteolytic starter cultures of Staphylococcus carnosus and Staphylococcus xylosus on biogenic amine production was examined during the fermentation process of dry sausages. Microbial counts (lactic acid bacteria, Micrococcaceae and Enterobactenaceae), pH, moisture and proteolysis-related parameters were also studied. The polyamines spermine and spermidine were the main amines found in the raw material and they only showed slight fluctuations during the fermentation. The four elaborated batches presented a significant (P < 0.001) formation of tyramine and putrescine. The main rate of amine production was during the first three days, when a sharp pH decrease and the development of lactic acid bacteria occurred. Sausages fermented with starters had lower amounts of tyramine than naturally fermented sausages (control), but differences in the Micrococcaceae counts were only significant during the first week of the ripening process. A slight formation of diaminopropane, cadaverine, agmatine, tryptamine and phenylethylamine was observed. The amounts of histamine were constant and remained below 0.5 mg/kg of dry matter, while serotonin, octopamine and dopamine were not detected. The sausages with Staphylococcus as starter culture showed strong proteolysis that was correlated with higher pH values than those of the control sausages. However, no positive correlation was found between the proteolysis index and biogenic amine production. Since proteolysis was stronger during the second half of the ripening process, the release of free amino acids as amine precursors occurred later than the early amine production.     

猪肉自然发酵香肠中细菌和乳酸菌对生物胺积累的作用

在猪肉香肠的自然发酵时，检测了选择的污染菌对形成的生物胺的性质和产量的作用。本文主要研究的是在肉腐败过程中胺的变化和微生物生长的变化，而且重点研究的是加入产酪胺的短乳杆菌（L．brevis）和产尸胺的阴沟肠杆菌（E．cloacae）的猪肉发酵香肠在发酵时生物胺的积累。在腐败和香肠发酵时相关微生物和胺的量较多。尸胺的高度积累和大量的不理想肠细菌有关，在香肠发酵时，酪胺的产生并不完全是乳酸菌的作用。另一方面，也涉及到必要的生产香肠的自然发酵菌，污染菌对于腐胺和其它生物胺的作用，现在还不清楚。     

大蒜精油和发酵剂对熏马肠中生物胺及微生物分布的影响

为研究大蒜精油和发酵剂对熏马肠中生物胺的影响,采用高效液相色谱法测定熏马肠中生物胺含量,利用 宏基因组学技术分析熏马肠中微生物多样性和生物胺含量的变化情况。结果表明：将大蒜精油和发酵剂联合使用能 够很好地减少熏马肠中尸胺、腐胺、组胺、酪胺和苯乙胺的产生,对控制生物胺在熏马肠中的含量起到非常显著的 作用;熏马肠中含有丰富的微生物物种,通过样品科分类水平物种分析,得出乳酸菌在熏马肠整个加工过程都是优 势菌种,而葡萄球菌在成熟后期数量较多。     

Effect of autochthonous starter cultures isolated from Siahmazgi cheese on physicochemical,microbiological and volatile compound profiles and sensorial attributes of sucuk,a Turkish dry-fermented sausage

The effect of adding autochthonous starter cultures isolated from Siahmazgi cheese, on the physicochemical parameters and microbial counts of sucuk was investigated during the ripening period. SPME–GC/MS was used in volatile compound analysis and a trained group of panelists carried out sensory analysis of the final product. After preliminary screening, three strains of Lactobacillus plantarum, which possess desirable technological properties, were used to prepare three starter cultures: LBP7, LBP10 and LBP14. The addition of LBP7 and LBP14 starter cultures had a significant effect (P < 0.05) on lightness, leading to higher L values compared to control sausages during the ripening period. Both LBP7 and LBP14 sausages showed higher counts of lactic acid bacteria, lower growth of Enterobacteriaceae and Gram-positive catalase-positive cocci and greatly lowered the pH value compared to control sausages throughout the ripening process. At the end of the ripening process, lactic acid bacteria counts were affected (P < 0.05) by the addition of starter culture since higher counts were observed in sausages prepared with LBP7 (9.14 log CFU/g) and LBP14 (8.96 log CFU/g) batches. The decrease of water activity during the ripening of sausages was not affected by the various starters. The texture profiles of all sausages were similar except for LBP10, which showed lower hardness and gumminess during ripening. Under the conditions of the study, volatile compounds were mainly from spices, and no marked differences were found among inoculated sausages. However, sensory evaluation revealed that most of the sensory attributes were scored higher for inoculated sausages than for the control ones. Therefore, LBP7 and LBP14 could be promising candidates for inclusion as starter cultures for the manufacture of sucuk.     

Analysis of biogenic amines in northern and southern European sausages and role of flora in amine production

The biogenic amine contents, microbial counts and flora producing amines were investigated in four types of fermented sausages. Southern type European sausages (Italian and Belgian) showed higher tyramine and phenylethylamine values than northern type ones (Norwegian and Belgian). The spontaneous non-starter lactic acid bacteria could be responsible for the production of these amines in the Italian products, and the cocci Gram positive in the Belgian South ones. The Norwegian sausages showed the lowest total amine content of those studied. The two Belgian types were characterised by the highest putrescine contents, associated with high counts of Enterococcus. The production of amines in vitro by the starter cultures used in the manufacture of the sausages revealed that none of the Lactobacillus species produced any amines and only Kocuria varians and Staphylococcus carnosus showed phenylethylamine and tryptamine production. High correlations were found between the content of putrescine, histamine and cadaverine.     

Effect of Starter Culture and Packaging on the Chemical,Microbiological and Sensory Quality of Turkish Soudjouck (Sucuk)

Lactobacillus plantarum, Micrococcus aurantiacus, and Pediococcus pentosaceus in different combinations and amounts were used for the production of fermented soudjouck. The effects of starter cultures on total aerobic bacteria, and selected chemical properties of samples were determined. Additionally, the effects of starter culture and packaging on the sensory characteristics of final product were studied. It was found that nitrite and sugar content of samples decreased during ripening, while protein and fat content relatively increased with drying. Mesophilic aerobic bacteria counts increased in the first days of ripening and then decreased, similar trend was also observed for the counts of all three starter cultures. Sensory results showed that reducing amount of starter culture negatively affected and incorporation of glucano delta lactone (GDL) into formula along with starter culture had an adverse effect on the sensory properties. It was demonstrated that vacuum packaging improved the sensory properties; therefore, it should be preferred over normal packaging.     

Novel starter cultures to inhibit biogenic amines accumulation during fish sauce fermentation

Bacteria with amine oxidase activity have become a particular interest to reduce biogenic amines concentration in food products such as meat and fish sausages. However, little information is available regarding the application of these bacteria in fish sauce. Hence, our study was aimed to investigate the effect of such starter cultures in reducing biogenic amines accumulation during fish sauce fermentation. Staphylococcus carnosus FS19 and Bacillus amyloliquefaciens FS05 isolated from fish sauce which possess amine oxidase activity were used as starter cultures in this study. Fermentation was held for 120 days at 35 °C. The pH value increased in all samples, while salt concentration remained constant throughout fermentation. Aerobic bacteria count was significantly lower (p < 0.05) in the control than in inoculated samples as a result of starter cultures addition. However, it decreased during fermentation due to the growth inhibition by high salt concentration. Proteolytic bacterial count decreased during fermentation with no significant difference (p > 0.05) among samples. These bacteria hydrolyzed protein in anchovy to produce free amino acid precursors for amines formation by decarboxylase bacteria. The presence of biogenic amines producing bacteria in this study was considered to be indigenous from raw material or contamination during fermentation, since our cultures were negative histamine producers. Amino acid histidine, arginine, lysine and tyrosine concentration decreased at different rates during fermentation as they were converted into their respective amines. In general, biogenic amines concentration namely histamine, putrescine, cadaverine and tyramine increased throughout fermentation. However, their concentrations were markedly higher (p < 0.05) in the control (without starter cultures) as compared to the samples treated with starter cultures. Histamine concentration was reduced by 27.7% and 15.4% by Staphylococcus carnosus FS19 and Bacillus amyloliquefaciens FS05, respectively. Both cultures could also reduce other amines during fermentation. After 120 days of fermentation, the overall biogenic amines concentration was 15.9% and 12.5% less in samples inoculated with Staphylococcus carnosus FS19 and Bacillus amyloliquefaciens FS05, respectively, as compared to control samples. These findings emphasized that application of starter cultures with amines oxidase activity in fish sauce fermentation was found to be effective in reducing biogenic amines accumulation.     

发酵剂对发酵香肠微生物及理化特性的影响

采用3种复合型发酵剂(VBL-97、VBM-60、SHI-59)和1种单一型发酵剂(BOM-13)生产发酵香肠,研究不同发酵剂对发酵香肠微生物及理化性质的影响。结果表明4组发酵香肠在发酵和成熟过程中,乳酸菌始终保持为优势菌,当达到成熟时,乳酸菌数在7.21~8.13 lgcfu/g范围内,葡萄球菌(除BOM-13外)高于5.50 lgcfu/g,肠杆菌科菌数低于3.00 lgcfu/g。BOM-13型发酵剂由单一清酒乳杆菌组成,发酵和成熟时间长于其他三组,所以成品的硫代巴比妥酸值(TBARS值,0.84 mg/100 g)和非蛋白氮值(NPN,0.46%)高于其它3组产品。由此可知由于发酵剂组成不同,相应地发酵条件(温度和时间)和成熟时间亦不同,但最终四种发酵剂都可生产出高品质产品(p H值5.3;AW0.82;NPN值高;TBARS值1.0 mg/kg;乳酸菌为优势菌且7.0 lgcfu/g;肠杆菌科菌3.0lgcfu/g)。VBL-97型发酵剂产酸能力和抗氧化能力强,而BOM-13型发酵香肠蛋白分解程度最高。     

混合发酵剂的筛选及对发酵猪肉香肠加工特性及安全性能的影响

通过比较不同比例植物乳杆菌与木糖葡萄球菌的复合发酵剂的生长活性、产酸能力、耐盐及耐亚硝酸盐特性,筛选最佳复配比例的混合发酵剂并制作发酵香肠。旨在探究复合发酵剂对发酵香肠理化品质及生物胺的影响。结果表明:植物乳杆菌与木糖葡萄球菌复合比为1:1时,具有较好的生长、产酸、耐盐及耐亚硝酸盐能力。接种1:1的植物乳杆菌与木糖葡萄球菌混合发酵剂制备的香肠pH值下降速率快于单一乳酸菌组和空白对照组;发酵结束混合组pH值降为4.95,显著低于对照组和单一组(P<0.05);pH值下降改变了蛋白质与水分结合能力、促使香肠Aw随之降低,使得混合组Aw低于单一组和对照组;相比香肠色泽,3组差异不显著(P>0.05)。成熟后期混合组尸胺和组胺检出量均低于单一组和对照组。由研究结果可知添加复合发酵剂有助于提高香肠安全性、缩短发酵成熟周期。     

接种乳酸菌发酵剂对风干肠成熟过程中微生物群落动态变化及感官品质的影响

为研究乳酸菌发酵剂对风干肠成熟过程中微生物数量、微生物多样性及感官品质的影响,分别将SHI-59(木糖葡萄球菌+戊糖片球菌+植物乳杆菌)、WBL-45(木糖葡萄球菌+肉葡萄球菌+清酒乳杆菌)、PRO-MIX5(木糖葡萄球菌+清酒乳杆菌+类植物乳杆菌)复合型商业发酵剂接种到肉馅中,经过12?d的成熟过程生产发酵型风干肠,...     

复合发酵剂和天然香辛料对羊肉发酵香肠品质特性的影响

通过接种复合发酵剂和添加天然香辛料,采用相同的工艺条件生产4组羊肉发酵香肠,1组为对照组,2组为接种发酵剂组,3组为发酵剂+黑胡椒组,4组为发酵剂+黑胡椒+孜然组。分别测定4个组羊肉发酵香肠在发酵成熟和贮藏过程中pH值、Aw值、水分含量及微生物的变化。结果表明:在发酵结束(即第1.5天)时,试验组和对照组的pH值、Aw值和水分含量均呈下降趋势,试验组的pH值迅速降到最低值(即5.0以下),与对照组差异显著(P<0.05);在干燥成熟过程中,试验组的pH值、Aw值和水分含量迅速下降,添加香辛料组的pH值迅速回升,同时乳酸菌数维持在108cfu/g以上水平,高于对照组,细菌总数却低于对照组;在贮藏过程中,试验组的pH值和水分含量基本保持不变,且均低于对照组,而Aw值始终呈下降趋势,细菌总数小于对照组。上述结果表明,接种复合发酵剂和添加天然香辛料能迅速降低pH值、Aw值和水分含量,有效抑制腐败菌和致病菌的生长,提高羊肉发酵香肠的品质和保藏性。     

Use of Fourier transform infrared spectroscopy to evaluate the proteolytic activity of Yarrowia lipolytica and its contribution to cheese ripening

The interaction between tyrosine-decarboxylase and proteolytic activities of a Lactobacillus curvatus and Staphylococcus xylosus, respectively, on biogenic amine production during the ripening and the storage of dry fermented sausages was investigated. Water content, pH, proteolysis parameters, microbial counts, and biogenic amine contents were monitored in spontaneously and starter fermented sausages. The use of proteolytic staphylococci as starter resulted in a higher content of non-protein nitrogen and total free amino acids. Tyramine was the main amine produced in all batches. However, tyrosine-decarboxylase activity of the L. curvatus starter strain was weak and yielded lower amounts of tyramine than those produced by the wild mioroflora in the control batch. Association between tyramine production and proteolysis could only be established in a defectively dried batch. Putrescine and cadaverine accumulation was efficiently reduced in the starter-mediated fermentation, in agreement with the lower development of enterobacteria. Phenylethylamine and tryptamine were only detected in the spontaneously fermented sausages, while histamine, spermine and spermidine did not vary during the ripening. Biogenic amine levels and related parameters showed significant changes during the storage of dry sausages depending on the temperature and the batch. As a general rule, changes in the pH, proteolysis, microbial counts, and biogenic amine contents were stronger at 19 degrees C than at 4 degrees C. The results suggest that refrigeration would be advisable for preventing further accumulation of biogenic amines during the storage of dry fermented sausages.     

BEHAVIOR OF STAPHYLOCOCCUS AUREUS IN SUCUK WITH NETTLE (URTICA DIOICA L.)

The behavior of Staphylococcus aureus was studied in sucuk (Turkish dry fermented sausage) with different levels of nettle (Urtica dioica L.). Sucuk batters containing different levels (1, 3 and 5%) of nettle were prepared and contaminated with S. aureus at approximately 10⁴ cfu/g. Sucuk batter not inoculated with S. aureus and not containing nettle addition was set as the control lot. Lactobacillus sakei Lb 706 was used as a starter culture. During ripening period, S. aureus, Micrococcus/Staphylococcus and lactic acid bacteria counts were determined. pH and water activity (a_w) values were also analyzed. The S. aureus count was under detectable levels in the control lot, and the pH level dropped below 5.0 after the first 24 h of fermentation. Initial pH values increased gradually in all three lots (1, 3 and 5%). At the end of the first 24 h of fermentation, a significant increase in S. aureus counts was determined in all lots of sausage except for the control lot. The pH value of the sucuk sample containing 1% nettle was under 5.0 on the second day. However, pH values for sucuk samples containing 3 and 5% nettle did not drop below 5.0 during the ripening period, including the fermentation phase. Nettle usage had no effect on the lactic acid bacteria count; however, it had significant effects on the Micrococcus/Staphylococcus count and a_w value.     

以干酪乳杆菌和葡萄球菌为发酵剂生产干发酵香肠过程中的主要理化和微生物变化

用干酪乳杆菌（ＬａｃｔｏｂａｃｉｌｕｓｃａｓｅｉＣＩＣＣ６０３３）、戊糖片球菌（ＰｅｄｉｏｃｏｃｕｓｐｅｎｔｏｓａｃｅｕｓＣＩＣＣ１０１９６）和弯曲乳杆菌（ＬａｃｔｏｂａｃｉｌｕｓｃｕｒｖａｔｕｓＣＩＣＣ６０３１）分别与葡萄球菌（Ｓｔａｐｈｙｌｏｃｏｃ－ｃｕｓｓｕｂｓｐ．ＣＩＣＣ１０１４５）按不同配比组成的９种发酵剂生产干发酵香肠，通过测定在发酵和成熟过程中的ｐＨ值，初选出６０３３和１０１４５的组合为合适的发酵剂。用该发酵剂生产干发酵香肠过程中的ｐＨ值、Ａｗ及活菌总数、乳酸菌数和球菌数的变化及感官分析的结果表明，最佳混合发酵剂的比例为６０３３∶１０１４５＝１∶２，最佳工艺条件为：２０℃，ＲＨ＞９５％，１ｄ；１６～１８℃，ＲＨ＝９０％～８５％，１５ｄ。实验中还对成品进行了理化分析和食品卫生检验。