首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Selected autochthonous starter (SAS) cultures (i.e. Lactobacillus sakei 8416, Lactobacillus sakei 4413, and L. sakei 8426, L. plantarum 7423 and L. curvatus 8427) were used as starter cultures in addition to a control treatment in the production of fermented sausages. The SAS cultures had a rapid growth and dominated the fortuitous population of LAB during the whole fermentation and ripening process improving the sensory attributes in comparison to control. Apart from the treatment produced with L. sakei 8416, all other SAS cultures prevented the lipid oxidation to values lower than 1 mg malonaldehyde/kg. The Micrococcaceae count and the redness of the sausages was not affected by the smoking and the acidification during the fermentation in the treatments produced with L. sakei 8416 and L. sakei 4413. The treatment of L. sakei 4413 had the lowest (*P < 0.05) content of all biogenic amines. In comparison to the control, the reduction of tyramine was 13%, tryptamine 55%, cadaverine 60% and putrescine 72%. Sausages produced with SAS cultures L. sakei 4413 and L. sakei 8416 had the highest scores for all sensory attributes. The results indicated that the SAS culture of L. sakei 4413 is the best autochthonous starter culture for fermented sausages.  相似文献   

2.
The aim of this study was to evaluate the bioconversion efficiency of rich in cellulose agro‐industrial by‐products such as wheat bran (WB), spent distiller's grain with solids (DGS), brewer's spent grain (BSG) and lupin (Lupinus angustifolius L.) wholemeal fraction (LF) to lactic acid (LA) using acid tolerant lactic acid bacteria (LAB) strains Lactobacillus sakei KTU05‐06, Pediococcus acidilactici KTU05‐7 and P. pentosaceus KTU05‐9. Carbohydrase preparation Depol? 692L was used for the hydrolysis of non‐starch polysaccharides. Analysed raw materials were suitable substrates for LAB propagation and L‐lactic acid production. The lowest pH (3.6) was found in LF medium after 48 h fermentation with P. acidilactici and P. pentosaceus strains. The lowest pH (3.86) was measured in WB fermented with L. sakei, and in DGS and BSG (pH 3.8 and 3.9 respectively) fermented with P. acidilactici. The highest endoxylanase activity was excreted by the P. acidilactici and P. pentosaceus (84 and 69 XU g?1 respectively), and the highest α‐amylase activity was of L. sakei (255.6 AU g?1) after 24 h incubation in WB medium. The L‐lactic acid concentration of 86.11 g kg?1 was reached after the bioconversion of hydrolysed WB in combination with 48 h fermentation by P. pentosaceus KTU05‐9 strain. LA contents between 222 and 282 mg kg?1 was produced from lupin processing residues via fermentation using P. acidilactici and P. pentosaceus KTU05‐9 strains. The major challenge within the presented study is the viability of tested LAB in cereal waste media and effective LA production at a low pH (3.63.8).  相似文献   

3.
Lactic acid bacteria (LAB) were isolated from traditional yogurt samples and genotypic characterization of these isolates revealed the presence of 21 distinct LAB strains belonging to Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Leuconostoc mesenteroides, and Lactobacillus plantarum as new LAB strains. Determination of the exopolysaccharide (EPS) production characteristics of the selected strains of each species revealed that all strains possessed at least one gene required for both homopolymeric‐ and heteropolymeric‐type EPS production. Structural analysis of the EPSs showed that L. delbrueckii subsp. bulgaricus Y39 and S. thermophilus Y102 produced heteropolymeric EPS containing glucose and galactose, whereas Leuc. mesenteroides Y35 and L. plantarum Y36 produced homopolymeric glucan‐type EPS. The level of EPS production in these strains was found to be in a similar range. These strains with EPS production characteristics are good candidates for future studies as new LAB for yogurt production.

Practical applications

Recent trends in yogurt production technology have led to an increased use of ropy starter cultures in yogurt production due to the technological roles of exopolysacharides (EPS) produced by these cultures. The main role of EPS in yogurt production is to improve the textural properties of yogurt as an in situ produced natural polymer. In addition to the yogurt starter cultures, use of adjunct cultures during production of yogurt is also of special interest to enhance the technological and nutritional characteristics of yogurt. Therefore, in this study, potential yogurt starter and adjunct cultures from traditional yogurt samples with EPS production characteristics were isolated. From these isolates, Lactobacillus delbrueckii subsp. bulgaricus Y39 and Streptococcus thermophilus Y102 produced heteropolymeric EPS containing glucose and galactose, whereas Leuconostoc mesenteroides Y35 and Lactobacillus plantarum Y36 produced homopolymeric glucan.  相似文献   

4.
Hu P  Xu XL  Zhou GH  Han YQ  Xu BC  Liu JC 《Meat science》2008,80(2):462-469
The effectiveness of Lactobacillus sakei B-2 inoculated as a protective culture on the inhibition of spoilage bacteria on sliced vacuum packed cooked ham was investigated by using culture-dependent and -independent approaches. Total microbial DNA was directly extracted from both control and treatment samples, and subjected to a nested PCR protocol, PCR–DGGE analysis was used to identify and monitor the dynamic changes in the microbial population, followed by partial 16S rDNA sequencing. The DGGE profile demonstrated that the protective culture effectively suppressed growth of predominant spoilage bacteria L. sakei, Lactobacillus curvatus and Leuconostoc mesenteroides in cooked ham during storage at 4 °C, however, growth of uncultured Leuconostoc was not inhibited. The shelf-life of this product inoculated with L. sakei B-2, at levels of 5.91 ± 0.04 log10 CFU g−1 was 35 days, compared to 15 days of control samples, when the ham was stored at 4 °C.  相似文献   

5.
Profiles of volatile organic compound (VOC) produced by nine individual lactic acid bacteria (LAB) during rye sourdough fermentation were compared by automated SPME and GC/MS‐Tof. The dough samples were inoculated with individual strains, placed inside the headspace vials and incubated during next 24 h. The production or loss of VOC‐s was followed by adsorbing volatiles onto 85‐m Car/PDMS fibre in every 4 h. Volatile profiles differed among LAB species and divided LAB into two main groups – hetero‐ and homofermentative. Hetrofermentative LAB (Lactobacillus brevis; Leuconostoc citreum; Lactobacillus vaginalis, Lactobacillus panis) showed high production of acetic acid, CO2, ethanol, ethylacetate, producing also hexyl acetate, ethyl hexanoate and isopentyl acetate. Whereas homofermentative LAB species (Lactobacillus helveticus; Lactobacillus casei; Lactobacillus sakei; Lactobacillus curvatus) produced a considerable amount of 2,3‐butanedione. Production of l ‐leucine methyl ester was unique for Lb. sakei, Lb. casei and Lb. curvatus strains. Lb. helveticus was the only LAB that produced benzaldehyde.  相似文献   

6.
The study aims to evaluate the technological properties of autochthonous strains (Lactobacillus sakei S15, Lactobacillus plantarum S24, L. plantarum S91, Pediococcus pentosaceus S128b and Staphylococcus carnosus G109) in Turkish dry fermented sausage (sucuk). After 24 h of fermentaPtion, all lactic acid bacteria strains reduced the pH to below 5.0, while the pH in the control group was above 5.3. The number of lactic acid bacteria strains reached 108–109 cfu g−1 during fermentation. Staphylococcus carnosus G109 remained at the inoculation level of 106 cfu g−1 during ripening. Lactobacillus sakei S15 as mono-culture showed higher TBARS values compared to other strains. The control group had the lowest L* value and autochthonous strains caused no significant difference for a* value. According to principal component analysis results, most volatile compounds were positively correlated with the group containing only L. sakei S15.  相似文献   

7.
Interactions of mixed cultures [lactic acid bacteria (LAB) and food‐borne pathogens (FBP)] on putrescine (PUT) as well as other biogenic amines (BAs) production were investigated in ornithine‐enriched broth. Significant differences in BAs production were found among the bacterial strains (P < 0.05). Conversion of ornithine into PUT by Salmonella Paratyphi A and Aeromonas hydrophila as well as Listeria monocytogenes and Staphylococcus aureus was high (>75 mg L?1), whereas other bacterial strains yielded below 50 mg L?1 of PUT. LAB strains resulted in significant reduction in PUT by Pseudomonas aeruginosa and Enterobacteriaceae, except for Escherichia coli, which was stimulated more than two‐fold PUT in the presence of Lactococcus lactis subsp. lactis. Lactobacillus plantarum had generally inhibition effect on histamine (HIS) and tyramine production by FBP, whereas Lc. lactic subsp. lactic slightly stimulated HIS by E. coli and A. hydrophila. Streptococcus thermophilus resulted in 1.5‐fold higher HIS formation by bacteria (10 mg L?1). Consequently, the interaction between LAB and specific FBP might result in significant inhibition of amine accumulation, if the correct LAB strains are used.  相似文献   

8.
The impact of free and encapsulated Lactobacillus plantarum addition on the physicochemical and microbiological properties during chilled storage (60 days) of dry-fermented sausages have been studied. Control (C) treatment was performed without probiotic incorporation, and the reformulation was comprised of L. plantarum as free cells (F) in alginate spheres (EA), in water-in-oil simple emulsion (ESM) and in water-in-oil-in-water double emulsion (EDM). After 60 days of storage, lower (P < 0.05) lipid oxidation was observed in F and EA (0.602–0.625 mg MDA kg−1) while it was higher (P < 0.05) in EDM (1.949 mg MDA kg−1). Treatments C and ESM presented intermediate TBARS levels compared to other treatments at the end of storage. All dry-fermented sausages presented high levels of lactic acid bacteria during the whole chilled storage (8.06–9.29 log CFU g−1 at day 0 and 8.02–9.35 log CFU g−1); however, EA treatment presented the highest L. plantarum viability even at 60 days of storage (8.34 log CFU g−1). Therefore, the strategy of L. plantarum inoculation in alginate spheres seems to be the best strategy for the delivery of probiotics during chilled storage of dry-fermented sausages.  相似文献   

9.
The objective of this study was to investigate the effect of starter culture addition on proteolysis of Thai fermented sausages. Sausages inoculated with six different external starter cultures—Pediococcus pentosaceous, Pediococcus acidilactici, Weissella cibaria, Lactobacillus plantarum, Lactobacillus pentosus, and Lactobacillus sakei—were compared with naturally fermented sausages. The results of microbiological analysis indicated that the dominance of lactic acid bacteria (LAB) could inhibit the growth of pathogens and spoilage. Proteolysis was observed during fermentation by the reduction of myofibrillar and sarcoplasmic proteins and the increase in nonprotein nitrogen (NPN) and total free amino acids. The highest increase in concentration of NPN and free amino acids was obtained from sausages inoculated with LAB. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed a similar pattern of proteolysis of sarcoplasmic proteins in all sausages, while that of the inoculated sausages with L. plantarum, L. pentsus, and L. sakei exhibited increased degradation of myofibrillar protein bands at 200 and 45 kDa.  相似文献   

10.
Flavour of type II sourdoughs is influenced by the ingredients, processing conditions, and starter culture composition. It is, however, not fully clear to what extent different sourdough lactic acid bacteria (LAB) contribute to flavour. Therefore, two types of flour (rye and wheat) and different LAB starter culture strains were used to prepare sourdoughs, thereby leaving the yeast microbiota uncontrolled. All LAB starter culture strains tested were shown to be prevalent and to acidify the flour/water mixture to pH values between 3.1 and 3.9 after 24 h of fermentation. Multiple aldehydes, alcohols, ketones, and carboxylic acids were produced by the sourdough-associated microbiota throughout the fermentation period. Based on the organoleptic evaluation of breads produced with these sourdoughs, five LAB strains were selected to perform prolonged wheat and rye fermentations as to their capacity to result in an acidic (Lactobacillus fermentum IMDO 130101, Lactobacillus plantarum IMDO 130201, and Lactobacillus crustorum LMG 23699), buttermilk-like (Lactobacillus amylovorus DCE 471), or fruity flavour (Lactobacillus sakei CG1). Upon prolonged fermentation, higher metabolite concentrations were produced. For instance, L. sakei CG1 produced the highest amounts of 3-methyl-1-butanol, which was further converted into 3-methylbutyl acetate. The latter compound resulted in a fruity banana flavour after 48 h of fermentation, probably due to yeast interference. Rye fermentations resulted in sourdoughs richer in volatiles than wheat, including 3-methyl-1-butanol, 2-phenylethanol, and ethyl acetate.  相似文献   

11.
Two different peptones obtained by enzymatic hydrolysis of yellowfin tuna (Thunnus albacares) head waste have been shown to be effective in promoting the growth of lactic acid bacteria (Lactobacillus bulgaricus Persian Type Culture Collection (PTCC) 1332, Lactobacillus acidophilus PTCC 1643, Lactobacillus casei PTCC 1608, Lactobacillus delbrukii PTCC 1333, Lactobacillus plantarum PTCC 1058, Lactococcus lactis PTCC 1336, and Lactobacillus sakei PTCC 1712). Peptones obtained from the enzymatic hydrolysis with Alcalase or Protamex were used instead of the standard peptones used in commercial MRS media. Peptones produced by Alcalase and Protamex had a 34% and 19% degree of hydrolysis, respectively. The results showed that the peptones from Alcalase and Protamex were better at promoting lactic acid bacteria (LAB) growth than the commercial MRS media (P < 0.05). The choice of proteolytic enzyme used to produce the fish hydrolysate had a considerable impact on the performance of the resulting hydrolysate, both in terms of maximum growth rate and biomass production. Peptones produced using Alcalase, with a higher degree of hydrolysis, induced better growth and performed better overall as an LAB substrate than those using Protamex. Current study revealed that enzymatic-modified fish by-products can be used as low cast nitrogen source for bacterial growth.  相似文献   

12.
Lactic acid bacteria (LAB) include species very closely related both physiologically and genotypically. Therefore, the identification of this bacteria group using conventional phenotypic methods is ambiguous and cumbersome. In this study, we have analyzed a recA gene fragment from 30 bacteria, including LAB and species common in the human gastrointestinal tract, aiming to evaluate the gene conservation among them and the development of primers and PCR conditions able to discriminate Lactobacillus plantarum strains from LAB closely related. The fragment with 995 bp of recA gene has grouped LAB, enterobacteria and bifidobacteria, in different clusters. A novel primer pair, LPrecAF and LPrecAR with 23 and 18 bp, respectively, has allowed the single amplification of a 108 bp fragment of L. plantarum strains contained in culture broth and fermented dairy samples. The observed detection limit for food samples and for cultures broth were 1 × 103 and 7 × 102 CFU mL−1, respectively. This approach proved to be a simple and efficient method for the identification and monitoring of L. plantarum in food, feeds, and culture broth. Moreover, the assay could be used in the studies from human or environmental microbiota.  相似文献   

13.
Recently, it was affirmed that the exopolysaccharides (EPSs) of Lactobacillus curvatus TMW 1.624, Lactobacillus reuteri TMW 1.106 and Lactobacillus animalis TMW 1.971 improve the quality of gluten-free breads and that they can be produced in situ to levels enabling baking applications. In this study we provide insight into the molecular and biochemical background of EPS production of these three strains. EPS formation strongly correlated with growth and took place during the exponential phase. Gtf genes were heterologously expressed, purified and their enzymatic properties as well as the structures of the EPSs formed were compared. Structural comparison of EPS formed by heterologously expressed glucosyltransferases (Gtfs) and of those formed by the wildtype lactobacilli confirmed that the respective genes/enzymes were identified and examined. The glucan formed by L. animalis Gtf was identified as a linear low molecular weight dextran. Optimal enzymatic conditions were pH 4.4 and 45 °C for the L. reuteri Gtf and pH 4.4 and 31 °C for L. curvatus Gtf. The Gtf from L. animalis had an optimal pH of 5.8 and displayed more than 50% of activity over a broad temperature profile (22–59 °C). The three Gtfs were stimulated by various mono- and divalent metal ions, dextran, as well as levan to different extents.  相似文献   

14.
In this study, the yields of exopolysaccharides (EPS) produced in situ during sourdough fermentations with Lactobacillus reuteri TMW 1.106 synthesizing glucan from sucrose were investigated under variation of the fermentation parameters dough yield (DY), pH, sucrose content and fermentation substrate. The obtained amounts of EPS after 1 day of fermentation were higher in softer (DY 500) than in firmer (DY 220) doughs. With the regulation of the pH to a constant value of 4.7, the optimum for EPS synthesis in liquid medium, the EPS production in dough also increased. The EPS yield could further be improved by additional sucrose fed-batch during fermentation. Fermentations with wheat flours, a rye-wheat mixture and rye bran with 10% sucrose as fermentation substrate showed, that the use of rye bran is a promising tool to get high dextran formation through L. reuteri even in the first 8 h of fermentation. Further, alternative production of oligosaccharides and organic acids from sucrose was investigated. Lactobacillus reuteri synthesized high amounts of acetic acid leading to low fermentation quotient values. In wheat doughs, the formation of maltooligosaccharides was observed. Confirmatory experiments with fructan producing Lactobacillus sanfranciscensis TMW 1.392 revealed the same trends with a few distinct differences, indicating that this approach is transferable to other EPS types and producers.  相似文献   

15.
The potential protective activity of lactic acid bacteria (LAB) from cold smoked salmon scraps was evaluated towards Listeria monocytogenes. Seventy‐three LAB strains were isolated and identified by biomolecular methods; Lactobacillus curvatus and Lactobacillus sakei prevailed. Three of the strains tested, identified as L. sakei, profile O, had a significant inhibitory activity against L. monocytogenes ATCC 19115 and clones DUP‐1042 and DUP‐18596. The evolution of microbial populations and chemical parameters were determined at time intervals to verify the shelf life. Listeria monocytogenes was isolated in half the packages also exceeding the legal limit. The shelf life of scraps was set at 30 days. Clonal characterisation of L. monocytogenes was performed by ribotyping. DUP‐1042, one of the human pathogen clones, was the most represented pattern. The results suggest further studies aimed at the selection of autochthonous nonspoilage LAB strains as bioprotective agents for cold smoked salmon.  相似文献   

16.
The influences of lactic acid bacteria (LAB) on biogenic amines formation by foodborne pathogens (FBP) were investigated. Biogenic amines production by single and mix cultures was tested in histidine decarboxylase broth. All of the mix cultures (LAB with FBP) inhibited significantly (P < 0.05) the ammonia accumulation except for Escherichia coli with Lactococcus lactic subsp. lactic and Lactobacillus plantarum. Although LAB with most of the pathogen showed considerably stimulation effects on putrescine, cadaverine, spermine, 2‐phenylethylamine, histamine (HIS), tyramine, trimethylamine, dopamine and agmatine (AGM), some of the LAB with pathogens showed poor inhibition effect on different amines formation. HIS production by Klebiella pneumonia was 0.16 mg L?1, whereas HIS value in presence of Lb. plantarum increased to 30.92 mg L?1. Consequently, LAB inhibition of the ammonium production by FBP is favourable, while the stimulation effects of LAB on biogenic amines formation by FBPs are not desirable for food industry.  相似文献   

17.
The aim of this research was to study the effects of solid‐state fermentation (SSF) with Lactobacillus sakei, Pediococcus pentosaceus and P. acidilactici on lupine sourdough parameters and lupine sourdough influence on the physical dough properties and wheat bread quality. The results showed that lactic acid bacteria (LAB) significantly reduced the pH and increased total titratable acidity (TTA) of SSF lupine. The highest protease activity in lupine is excreted by L. sakei (187.1 ± 8.6 PU g?1), and the highest amylase activity, by P. pentosaceus (155.8 ± 7.5 AU g?1). Lupine sourdough has a significant effect on the rheological properties of doughs, which affect the baking characteristics of the final product. In conclusion, it can be said that L. sakei, P. pentosaceus and P. acidilactici could be used for lupine SSF, and the addition of up to the 10% SSF lupine products increases the wheat–lupine bread quality.  相似文献   

18.
BACKGROUND: Yan‐jiang (fermented ginger) is a popular traditional fermented food in Taiwan. The lactic acid bacteria (LAB) microflora in yan‐jiang has not been studied in detail. In this study, LAB from yan‐jiang were isolated, characterised and identified. RESULTS: A total of 176 LAB were isolated; 160 cultures were isolated from yan‐jiang samples and 16 cultures were isolated from raw ginger. These isolates were characterised phenotypically and then divided into nine groups (A to I) by restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. Lactobacillus sakei and Lactococcus lactis subsp. lactis were the major LAB found in the initial 2 days of fermentation without pickled plums; these species were mostly replaced by Weissella cibaria and L. plantarum after 3 days of fermentation. In the fermentation bucket with added pickled plums, W. cibaria was the most abundant LAB found during fermentation. The antibacterial activities of the isolates were determined. Twenty‐four Lc. lactis subsp. lactis and 19 W. cibaria strains showed inhibitory activity against the indicator strain L. sakei JCM 1157T. CONCLUSION: Results demonstrate that various LAB species were more numerous when fermentation was carried out without pickled plums. LAB also had effects on the aroma and flavour of yan‐jiang. Copyright © 2011 Society of Chemical Industry  相似文献   

19.
Growth of Lactobacillus plantarum 70810, Lactobacillus rhamnosus 6005 and a commercial yogurt starter culture in soymilk was investigated in the present study. It was found that the fermented soymilk using L. plantarum 70810 had significantly higher viable cell counts, water holding capacity (WHC, 88.27%), apparent viscosity (1840.35 mPa s) and exopolysaccharide (EPS) amount (832.15 mg/L) than the other two starter cultures in soymilk. Direct observation of microstructure in fermented soymilk indicated that the network structures of EPS-protein could improve the texture of fermented soymilk. Considering that the beneficial effects of L. plantarum 70810 in fermented soymilk, volatile compounds in fermented soymilk were further identified. Then the growth and fermentation characteristics of L. plantarum 70810 including changes in viable cell counts, pH, titratable acidity, apparent viscosity and EPS production during storage were investigated. In comparison to original soymilk base, the concentrations of the characteristic flavor compounds for fermented soymilk using L. plantarum 70810 increased, whereas hexanal, 2-pentylfuran and 2-pentanone in relation to beany flavor of soymilk decreased. In addition, fermented soymilk using L. plantarum 70810 maintained high viable cell count (>108 cfu/mL), apparent viscosity (966.43 mPa s) and amounts of EPS (635.49 mg/mL) during storage at 4 °C for 21 days.  相似文献   

20.
The probiotic strains Lactobacillus brevis CCMA1284 and Lactobacillus plantarum CCMA0359 were microencapsulated by spray drying using different matrices – whey powder (W), whey powder with inulin (WI) and whey powder with maltodextrin (WM). Viability of the microencapsulated strains in acid and bile juices and during 90 days of storage (seven and 25 °C) was evaluated. The two strains exhibited high encapsulation efficiency (> 86%) by spray drying. The different matrices maintained L. plantarum viability above six log CFU g−1 at 7 °C for 90 days, whereas similar results for L. brevis were observed only for W. The use of inulin as matrix of encapsulation did not enhance bacterial viability in the evaluated conditions. In general, the use of W and WM as matrices was effective for L. plantarum viability. However, only W was effective for L. brevis in the evaluated conditions. The spray drying technique was successfully adopted for the encapsulation of L. plantarum CCMA0359 and L. brevis CCMA1284 strains.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号