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。     

Characterization of lactic acid bacteria isolated from a Greek dry-fermented sausage in respect of their technological and probiotic properties

A total of 147 lactic acid bacteria was isolated from two types of naturally fermented dry sausages at four different stages of the ripening process studied in order to select the most suitable strains according to their technological characteristics including probiotic properties and antimicrobial activity against food-borne pathogens. Identification of the isolates revealed that 90% were lactobacilli, 4% enterococci, 3% Pediococcus sp. and sporadic isolates of Weissella viridescens, Leuconostoc pseudomesenteroides, and Leuconostoc sp. The isolated strains of Lactobacillus sakei (49 isolates), Lactobacillus curvatus (24 isolates) and Lactobacillus plantarum (7 isolates) were further characterized. All strains could grow at 15?°C, whereas the majority of the strains was able to grow in the presence of 6.5% NaCl and on acetate agar. The enzymatic potential of the strains was evaluated using the API ZYM system. During in vitro investigations all strains exhibited high leucine and valine aminopeptidase activities and moderate acid phosphatase and phosphohydrolase activities. Some strains showed very weak lipolytic activity. The enzyme profiling is an important factor for selection of strains as starter cultures. A large majority of the strains tolerated 0.1% bile salts whereas 58% of Lactobacillus curvatus strains and all Lactobacillus plantarum strains were resistant to 0.3% bile salts. All Lactobacillus sakei strains and the majority of Lactobacillus curvatus and Lactobacillus plantarum strains exhibited an anti-listerial activity against three Listeria monocytogenes strains. A percentage of 75, 50 and 29% of Lactobacillus sakei, L. curvatus and L. plantarum strains, respectively, could inhibit two Staphylococcus aureus strains. The contribution of the selected strains to a possible inhibition of Listeria monocytogenes and S. aureus in situ on fermented meats would be of considerable interest to enhance the hygienic quality of these products.     

韩国泡菜加工过程中微生物区系的研究

为了解韩国泡菜在制作过程中微生物的区系,分离鉴定其在腌制、发酵过程中的优势微生物。结果表明：韩国泡菜腌制过程中优势乳酸菌经鉴定为短乳杆菌（Lactobacillus brevis）、植物乳杆菌（Lactobacillusplantarum）;优势酵母菌为近平滑假丝酵母（Candida parapsilosis）、粗状假丝酵母（Candida valida）;韩国泡菜在发酵过程中的优势乳酸菌为植物乳杆菌（Lactobacillus plantarum）、弯曲乳杆菌（Lactobacillus curvatus）、短乳杆菌（Lactobacillus brevis）、肠膜明串珠菌肠膜亚种（Leuconostoc mesenteroides subsp. mesenteroides）;优势酵母菌为近平滑假丝酵母（Candida parapsilosis）、粗状假丝酵母（Candida valida）、酿酒酵母（Saccharomyces cerevisiae）。     

Characterization and selection of autochthonous lactic acid bacteria isolated from traditional Iberian dry-fermented salchichón and chorizo sausages

ABSTRACT:  A total of 192 lactic acid bacteria were isolated from 2 types of naturally fermented dry sausages at 3 different stages of the ripening process in order to select the most suitable strains as starter cultures in dry-cured sausage manufacture according to their technological characteristics such as glucose fermentation, lactic and acetic acid production, and proteolytic, lipolytic, and antimicrobial activities. Identification of the isolates revealed that 31.2% were Pediococcus pentosaceus , 26.9% Lactococcus lactis , 18.6% Pediococcus acidilactici , 17% Lactobacillus brevis , and sporadic isolates of Leuconostoc mesenteroides , Lactobacillus plantarum , and Lactobacillus curvatus . Most of the strains did not produce gas from glucose and showed the capacity to produce lactic acid rapidly. Some 25% of the strains were able to degrade tributyrin (esterase activity), but none showed lipolytic activity against olive oil and pork fat. Only 3 strains of P. acidilactici showed weak proteolytic activity against myofibrillar or sarcoplasmic proteins. Also, the same strains showed antimicrobial activity against Listeria monocytogenes . Nine strains with the best properties were preselected and tested for biogenic amine production. The results showed that two of the strains, identified as P. acidilactici by polymerase chain reaction, had the potential to be further tested as starter cultures in pilot processing of Iberian sausages.     

发酵风干肠中乳酸菌的发酵性能

对从自然发酵风干肠中分离的6 株乳酸菌的发酵性能进行评价,主要包括测定菌株的生长曲线、产酸能力、对NaCl及NaNO2的耐受能力,同时通过吲哚实验和抗生素敏感性测定对菌株的安全性进行初步评价。结果表明：6 株乳酸菌生长趋势接近,均在8 h左右进入生长稳定期,pH值在0～8 h下降最快,清酒乳杆菌和发酵乳杆菌的产酸能力更强;所有菌株均可在6 g/100 mL NaCl和0.015 g/100 mL NaNO2条件下生长,植物乳杆菌和弯曲乳杆菌的NaCl耐受能力最优,清酒乳杆菌和发酵乳杆菌则对NaNO2具有最强的耐受能力;吲哚实验中6 株乳酸菌的反应结果均为阴性,对实验所选抗生素无耐药性,说明6 株乳酸菌具有较好的发酵性能和安全性,可作为功能性发酵剂用于发酵肉制品的生产。     

Functional properties of Lactobacillus strains isolated from kimchi

The objective of this study was to evaluate the functional properties of lactic acid bacteria (LAB) from kimchi, a traditional Korean fermented vegetable product generally consumed raw as a side-dish with practically every meal.Twelve mild acid producing facultatively heterofermentative Lactobacillus strains were selected for their potential as starter cultures for fermentation of kimchi, and evaluated for their functional properties. Eleven strains were identified as Lactobacillus sakei and one as Lactobacillus plantarum. The strains identified as L. sakei differed in some physiological features; of particular interest was the fact that 9 of these strains produced L(+) lactic acid from glucose in presence of acetate.All strains were able to survive gastrointestinal conditions simulating stomach and duodenum passage. In addition, they showed higher adherence to HT-29 cells than Lactobacillus rhamnosus GG, a commercial probiotic strain used worldwide. These strains also showed antimicrobial activity against a number of food-borne pathogens. Their ability to lower cholesterol was demonstrated by BSH (bile salt hydrolytic) activity, and cholesterol assimilation tests in vitro. The results suggest the probiotic potential of these strains for use in kimchi fermentation.     

腌腊肉制品中乳酸菌的筛选鉴定及其在腊肠中的应用

为筛选适合传统腌腊肉制品的优良乳酸菌菌株,从多种农家自制传统腌腊肉制品中分离纯化出9株优势乳酸菌。通过发酵特性筛选,得到一株性状优良菌株10M-7,并制备该菌株的干粉发酵剂,以未接种发酵剂腊肠为对照,分析此发酵剂对腊肠感官品质和微生物变化的影响。结果表明,10M-7菌株具有良好的产酸特性和抑菌性能。根据形态学、生理生化特征和16S rRNA序列分析,鉴定其为植物乳杆菌,采用冷冻干燥法制备纯种发酵剂,并制作人工发酵腊肠。发酵剂组pH值在初期便迅速下降,且始终低于对照组;发酵剂组乳酸菌迅速生长繁殖,且葡萄球菌和大肠杆菌数量与对照组相比明显降低。感官评价表明,当添加量为10~4CFU/g原料肉时,能够很好地保持和改善产品风味,使产品整体感觉更好。     

Identification of potential probiotic starter cultures for Scandinavian-type fermented sausages

Potential probiotic cultures suitable as starter cultures for the Scandinavian-type fermented sausages were identified among strains well-adapted to fermented meats as well as strains originating from a culture collection. From 15 different fermented meat products, 22 strains were isolated as dominant non-starter lactic acid bacteria (NSLAB). The isolates were identified by RAPD, API and sequence analysis of 16S rRNA and showed to be five strains of Lactobacillus sakei, five strains of Lactobacillus farciminis, five strains belonging to the group of Lactobacillus plantarum/pentosus, four strains of Lactobacillus alimentarius, two strains of Lactobacillus brevis and one strain of Lactobacillus versmoldensis. Heterofermentative strains as well as strains not growing at 37 degrees C and not lowering pH below 5.1 in a meat model were excluded leaving 9 strains for further studies. These strains together with 19 strains from a culture collection were evaluated by in vitro methods including survival upon exposure to pH 2.5 or 0.3% oxgall and adhesion to the human colon adenocarcinoma cell line Caco-2 as well as antimicrobial activity against potential pathogens. Strains that fulfilled all the probiotic criteria and showed to be fast acid producers in a meat model included three strains belonging to the group of Lb. plantarum/pentosus (MF1291, MF1298, MF1300) which originated from the dominant NSLAB of fermented meat products. MF1291 and MF 1298 were further identified as Lb. plantarum and MF1300 as Lb. pentosus. The three strains were all successfully applied as starter cultures for the production of fermented sausage. The viable count at the end of the processing period reached high cell numbers (4.7x10(7)-2.9x10(8) cfu/g) and pH of the sausages decreased to pH 4.8-4.9 without any flavour deviation compared to sausage fermented by a commercial meat starter culture.     

Effect of Lactobacillus plantarum as a starter on the food quality and microbiota of kimchi

Lactobacillus plantarum has been reported to be responsible for acid increase at the later stage of kimchi fermentation and considered not inappropriate as a starter of kimchi. If functional L. plantarum strain can survive in large quantity in kimchi during fermentation, it may endow new functionality to kimchi. After 12 day fermentation at 4°C, L. plantarum, Leuconostoc mesenteroides, Weissella cibaria, Weissella confusa, and Lactobacillus sakei were the most prevalent ones in kimchi without a starter. In kimchi with a starter, L. plantarum was detected from the 1 day fermentation and throughout 25 day fermentation. There was no difference in pH between 2 kinds of kimchi. The acid content after the 21 day increased more in kimchi with starter when most kimchi is consumed before this time. Survival of a starter strain throughout the whole fermentation suggested the possible use of various functional lactic acid-producing bacterias (LABs) to kimchi endowing a new beneficial function to kimchi.     

泡菜发酵乳酸菌的分离鉴定及耐药性分析

对吉林地区朝鲜族自制泡菜中的发酵乳酸菌进行分离鉴定,并对菌株耐药情况进行分析,以期为泡菜发酵菌的风险评估奠定基础。采集吉林省多个不同地区的泡菜制品,通过MRS培养基分离,16S rDNA测序,分析其乳酸菌种类及数量,同时采用平板琼脂稀释法进一步检测了分离菌对10 种临床常用抗生素的药物敏感性。结果表明,从15 份不同厂家泡菜中共分离得到34 株乳酸菌,分别为植物乳杆菌12 株,短乳杆菌5 株,鼠李糖乳杆菌3 株,干酪乳杆菌2 株,清酒杆菌2 株,肠膜明串珠菌2 株,嗜热链球菌2 株,食窦魏斯氏乳杆菌1 株,弯曲乳杆菌1 株,棒状乳杆菌1 株,嗜酸乳杆菌1 株,坚强肠球菌1 株,Lactobacillus namurensis 1 株。药敏实验结果表明,所有菌株对氨苄西林和氯霉素敏感,对其他抗生素均有不同程度的耐药性,其中对环丙沙星耐药率最高。     

Production of salami from ostrich meat with strains of Lactobacillus sake, Lactobacillus curvatus and Micrococcus sp

The aim of this study was to produce Italian-type salami from ostrich meat using different combinations of Lactobacillus sake, Lactobacillus curvatus and Micrococcus sp., and to compare the sensory characteristics of these products to that of salami produced with glucono-delta-lactone (GdL). Meat inoculated with starter cultures was fermented for four days (20-22 °C, 97-99% RH) and ripened for a further 11 days (16-18 °C, 40-60% RH). Cell counts of lactic acid bacteria and micrococci, and changes in pH were determined daily during fermentation. According to texture and sensory evaluation, the best salami was produced by a starter culture containing L. curvatus DF 38 and Micrococcus sp. MC 50.     

Proteolytic and lipolytic starter cultures and their effect on traditional fermented sausages ripening and sensory traits

In this study, three starter formulations including Lactobacillus curvatus and Staphylococcus xylosus strains selected in vitro on the basis of their lipolytic and proteolytic activities were employed for the manufacture of traditional fermented sausages of southern Italy. Microbial population, proteolysis, lipolysis, changes in free amino acids (FAA) and free fatty acids (FFA) and development of characteristic taste and flavor of the final product were investigated. Proteolysis and lipolysis were observed in sausages inoculated with proteolytic and lipolytic S. xylosus coupled with L. curvatus, while the sausage started with only S. xylosus without lactobacilli was identical to the non-inoculated control, indicating that the proteolysis could be due to both microbial activity and endogenous proteases activated by the decrease in pH. The statistical analysis applied to the instrumental and sensory data showed that there was an effect of the starter used on the characteristics of the sausage obtained. In particular, the control samples showed very close features different from the sausages obtained by adding starter cultures. Finally, analyzing the sensory parameters the sausages ripened without starter addition and those started without the L. curvatus AVL3 showed similar features indicating an influence of the presence of the lactobacilli on the final organoleptic quality of the sausages. An appropriate choice of a combination of strains in a starter formulation is fundamental to obtain products of the expected quality.     

可降解亚硝酸盐植物乳杆菌在广式腊肠发酵中的应用

目的:以可降解亚硝酸盐的植物乳杆菌为发酵剂,分析探讨广式腊肠制作中使用该发酵剂的产品特征。方法:研究两株植物乳杆菌分别对2%氯化钠和300 mg/kg亚硝酸钠的耐受性,以及在MRS培养基中降解亚硝酸盐的能力。并以其中一株植物乳杆菌为发酵剂加入广式腊肠中,测定不同发酵时间产品的pH值、水活度以及乳酸菌、霉菌和大肠菌的生长情况,与对照组进行比较,研究该发酵剂对发酵腊肠产品特征的影响。结论:将具有良好耐盐和耐亚硝酸盐能力,同时对亚硝酸盐具有较强降解能力的H1菌作为发酵剂加入腊肠后,降低了腊肠的pH值,同时对有害菌有明显的抑制效果,说明所选植物乳杆菌具有较好的环境适应性并显示出强大的酸化潜力,能通过抑制肠杆菌科的生长,提高微生物的安全性。因此,H1菌有望成为一种具有生物安全性的本土发酵剂。     

Tyramine degradation by micrococci during ripening of fermented sausage

The ability of tyramine oxidase exhibiting strains of Micrococcus varians to degrade tyramine in vivo during sausage fermentation was investigated. Fermented sausage was produced with a tyramine forming strain of Lactobacillus curvatus which acquired a final tyramine concentration of 190ppm. The addition of either one of two strains of M. varians exhibiting a potential to oxidise tyramine decreased the amount of tyramine formed to 160 and 150ppm, respectively. No effect on growth of L. curvatus and pH development in the fermented sausage was observed when micrococci were present during a three weeks ripening period. Sausage fermentation was further carried out with a non-amine forming strain of L. sake and M. varians after addition of 100ppm tyramine to the raw material. The amount of tyramine in the end product was 60ppm, and during the first 10 days of ripening the decrease was faster on the outside of the sausage.     

PROTEOLYTIC ACTIVITY OF BACTERIAL STARTER CULTURES FOR MEAT FERMENTATION

Proteolytic activity of fermented meat starter cultures Pediococcus acidiliactic, Lactobacillus sake, Lactobacillus curvatus, Streptomyces griseus, Staphylococcus xylosus and Staphylococcus carnosus was examined after inoculation of sterile beef protein extracts containing 1% dextrose. Analysis for primary amines in extracts generated during fermentation of glucose showed that L. sake had the highest (P<0.05) proteolytic activity. The other cultures ranked from highest to lowest activity as follows : L. curvatus < S. carnosus < S. griseus < P. acidilactici < S. xylosus. All inoculated extracts showed a pH decline by 96 h to pH 3.76-4.31 whereas the control extract remained at 6.0-5.95. All cultures except S. xylosus had CFU increases within 24 h of inoculation. Only L. sake and S. xylosus had counts less than their initial level after 96 h. The results provide evidence that these commercially available starters for meat fermentation do possess significant proteolytic activity when tested using beef protein extracts.     

Growth inhibition of Listeria monocytogenes by a bacteriocin of Pediococcus acidilactici M during fermentation of kimchi

Four lactic acid bacteria known to produce bacteriocins were evaluated for the inhibitory effect against Listeria monocytogenes strain Scott A. Lactococcus lactis subsp. lactis biovar diacetylactis 26-2 was the least antilisterial, whereas Pediococcus acidilactici M resulted in the largest zone of inhibition on an agar medium. Leuconostoc paramesenteroides OX and Lactobacillus sake Lb 706 were intermediate. Aqueous solutions of crude bacteriocin powders derived from supernatant fluids of L. sake Lb 706 and P. acidilactici M. cultures inhibited the growth of Lactobacillus plantarum UGA8 in MRS agar. The addition of 10 mg of crude bacteriocin powder from L. sake to 150 g of kimchi fermented at 14 ± 1°C for 16 days had no effect on the growth of L. monocytogenes. The same amount of crude bacteriocin derived from P. acidilactici, however, had an initial lethal effect on L. monocytogenes and controlled growth of the pathogen throughout the 16-day fermentation. The successful application of bacteriocins to control the growth of L. monocytogenes in lightly fermented foods such as kimchi would appear to be achievable.     

Characterisation of the Lactobacillus community in traditional Karst ewe's cheese

Ewe's cheese, produced in the Slovenian Karst region, was analysed for its lactobacilli population. Biochemical fingerprinting with PhenePlate™ LB grouped lactobacilli in 16 distinct PhP types. One representative from each PhP type was further analysed. Members of Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus curvatus, and Lactobacillus brevis species were determined phenotypically. The genus-specific DNA band was amplified with all PhP representatives, whereas species-specific polymerase chain reaction efficiently determined only L. paracasei and L. brevis. Lactobacilli were highly to moderate sensitive to six antibiotics, and resistant to vancomycin. From halo formation in the agar spot method, indicators exerted a promising level of sensitivity for antimicrobials, produced by test microorganisms. Lactobacilli from Karst ewe's cheese offer a remarkable reservoir of 'natural' microbes.     

1 株高效降胆固醇乳酸菌的功能与发酵特性

通过研究乳酸菌X3-2B降胆固醇功能特性以及在发酵香肠中的发酵特性,确定高效降胆固醇性能的肉制品发酵剂。结果表明：菌株X3-2B在培养温度为30 ℃、pH 5.5时胆固醇降解率最大,在MRS胆固醇筛选培养基中其胆固醇降解率最大且优于标准菌株植物乳杆菌（L. plantarum,LP）。并以菌株X3-2B为发酵剂做的发酵香肠其水分活度、pH值在相同天数时下降程度显著优于自然发酵组（P＜0.05）,色泽、乳酸菌数都优于对照组,且发酵香肠14 d与0 d相比,添加发酵剂的发酵香肠胆固醇含量显著降低（P＜0.05）且在贮存56 d时X3-2B组发酵香肠胆固醇含量低于自然发酵组与LP组,故菌株X3-2B可作为一株降胆固醇性能较好的肉制品发酵剂。     

接种乳酸菌发酵剂对风干肠加工过程中理化性质及安全品质的影响

为研究乳酸菌发酵剂对风干肠在加工过程中理化性质及安全品质的影响,本试验分别将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,3个接菌组分别用SHI、WBL、PRO表示,经过...     

Monitoring the bacterial population dynamics during fermentation of artisanal Argentinean sausages

The dynamics of the microbial community responsible for the artisanal fermentation of dry sausage produced in Argentina was investigated by using classical and molecular approaches. The combined use of RAPD analysis with primers M13, XD9, RAPD1 and RAPD2 and 16S rDNA sequencing were applied to the identification and intraspecific differentiation of 100 strains of lactobacilli and Micrococcaceae. DGGE analysis was used to monitor the dynamic changes in population after total microbial DNA was directly extracted from sausages and subjected to PCR using V3f (GC), Bact-0124f-GC and Univ-0515r primers. The sequence analysis of 16S rDNA of the dominant species was also carried out. Lactobacillus sakei and Lactobacillus plantarum were the dominant lactic acid organisms during the fermentation while Staphylococcus saprophyticus represented the dominant species of Micrococcaceae. It was demonstrated that the ripening process of Argentinean artisanal fermented sausage is driven by a limited number of Lactobacillus and Staphylococcus strains selected from environmental microbiota by the ability to best compete under the prevailing conditions of the ecological niche. The identification of dominant communities present in this artisanal fermented sausage can help in the selection of starter cultures consisting in well adapted strains to the particular production technology.