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 233 毫秒
1.
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   

2.
Kimchi is often stored for a long period of time for a diet during the winter season because it is an essential side dish for Korean meals. In this study pH, abundance of bacteria and yeasts, bacterial communities, and metabolites were monitored periodically to investigate the fermentation process of kimchi for 120 d. Bacterial abundance increased quickly with a pH decrease after an initial pH increase during the early fermentation period. After 20 d, pH values became relatively stable and free sugars were maintained at relatively constant levels, indicating that kimchi fermentation by lactic acid bacteria (LAB) was almost completed. After that time, a decrease in bacterial abundance and a growth in Saccharomyces occurred concurrently with increased free sugar consumption and production of glycerol and ethanol. Finally, after 100 d, the growth of Candida was observed. Community analysis using pyrosequencing revealed that diverse LAB including Leuconostoc citreum, Leuconostoc holzapfelii, Lactococcus lactis, and Weissella soli were present during the early fermentation period, but the LAB community was quickly replaced with Lactobacillus sakei, Leuconostoc gasicomitatum, and Weissella koreensis as the fermentation progressed. Metabolite analysis using 1H‐NMR showed that organic acids (lactate, acetate, and succinate) as well as bioactive substances (mannitol and gamma‐aminobutyric acid (GABA)) were produced during the kimchi fermentation, and Leuconostoc strains and Lactobacillus sakei were identified as the producers of mannitol and GABA, respectively. Practical Application In this study, we have shown that the growth inhibition of yeasts including Saccharomyces and Candida is necessary to extend the shelf life of kimchi in long‐term storage. Additionally, we have shown that a mixed culture of Leuconostoc strains and Lactobacillus sakei is necessary to produce kimchi that contains both mannitol and gamma‐aminobutyric acid.  相似文献   

3.
The microbiological and physicochemical changes of industrially fermented Halkidiki and Conservolea green table olives were determined. Samples were analysed to monitor the population of lactic acid bacteria (LAB), yeasts and Enterobacteriaceae, together with changes in pH, acidity, salinity, colour, lactic acid, acetic acid and ethanol. LAB and yeast species diversity was evaluated at the beginning (1 day), middle (75 days) and final (135 days) stages of fermentation by RAPD-PCR genomic fingerprinting. Results revealed vigorous lactic acid processes as indicated by the dominance of LAB over yeasts. No Enterobacteriaceae could be detected after 30 days. Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) dominated in the beginning of fermentation in both varieties. In the end, Lactiplantibacillus pentosus (formerly Lactobacillus pentosus) and Pediococcus ethanolidurans prevailed in Halkidiki and Conservolea varieties, respectively. As for yeasts, Kluyveromyces lactis/marxianus and Pichia manshurica prevailed at the onset of fermentation in Halkidiki and Conservolea varieties, whereas in the end Pichia membranifaciens dominated in both varieties.  相似文献   

4.
Four strains and 2 strains of lactic acid bacteria (LAB) were isolated from the commercial yogurt and kimchi products in Korea, respectively. Based on the 16S rRNA sequencing data, strain A from a drink-type yogurt manufactured by dairy company S, was a Gram-positive, rod-shaped Lactobacillus helveticus, and both strain B (company N) and D (company H) were identified as L. casei ssp. casei, and strain C (company L) as L. paracasei. None of yogurt strain B and D was recovered from the samples exposed to the simulated gastric juice, pH 2.0 for 1.5 hr. Of the 6 isolates tested, strain YS93 from kimchi was the most resistant to acidic condition using the simulated gastric juice, pH 2.0. Moreover, it was shown that 2 kimchi isolates and yogurt strain D produced antibacterial substances, probably bacteriocin-like peptide, which was inhibitory against Staphylococcus aureus as an indicator. In an adhesion assay using a Caco-2 cell, the adherence activity of kimchi strains YS29 and YS93 was significantly higher than those of 4 yogurt starter strains tested.  相似文献   

5.
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   

6.
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   

7.
The effect of different temperatures (25°C, 18°C and ambient temperature) and NaCl levels in brines (4%, 6% and 8%) on the microbiological and physicochemical characteristics of naturally black olives of Conservolea variety was studied for up to 190 days. Fermentation was carried out according to the traditional anaerobic method. The initial microflora consisted of Gram-negative bacteria, lactic acid bacteria and yeasts. Inhibition of Gram-negative bacteria was evident in all fermentations. The prevailing micro-organisms were lactic acid bacteria and yeasts, the association of which was dependent on the conditions of fermentation. At 25°C and 18°C in brines containing 4% and 6% NaCl, the growth of lactic acid bacteria was favoured resulting in a lactic acid fermentation, as indicated by the high free acidity levels and low pH values in the brines. On the contrary, 8% NaCl concentration affected the growth of lactic acid bacteria and enhanced the activity of fermentative yeasts, producing a final product with lower free acidity and higher pH value. At ambient temperature, the counts of lactic acid bacteria followed the fluctuation of temperature regardless of salt concentration, while yeasts did not seem to be affected. The lactic acid bacteria identified belonged to the species Lactobacillus mesenteroides, Lactobacillus brevis, Lactobacillus plantarum and Lactobacillus pentosus. The best conditions for fermentation were at 25°C and 6% NaCl, developing free acidity of 142 mM (1·28% w/v) lactic acid and pH value of 3·8. After 5 months of brining, olives fermented at 25°C were judged by panelists as being debittered and ready to eat. No off-odour development was detected in any case due to anomalous fermentation. The HPLC analysis revealed that citric, malic, tartaric, succinic, lactic and acetic were among the end products of fermentation.  相似文献   

8.
眉山泡菜中乳酸菌的分离鉴定   总被引:1,自引:0,他引:1  
目的:分析眉山泡菜的基本数据和乳酸菌的菌种构成。方法:从眉山市采集泡菜12 份,测定pH值、总酸度、盐度、乳酸菌计数,用16S rRNA序列分析法鉴定菌种。结果:样品pH值的范围是3.37~3.89,总酸度的范围是0.65~0.92 g/100 g(以乳酸计),盐度的范围是4.16%~5.28%(以NaCl计),MRS和M17乳酸菌计数分别是1.71~6.33、1.33~5.78(lg(CFU/g))。总酸度对乳酸菌计数影响最大。共分离鉴定出16 株乳酸菌:Lactobacillus fermentum(2 株)、Lactobacillus plantarum(3 株)、Lactobacillus brevis(2 株)、Lactobacillusacidophilus(1 株)、Lactobacillus casei(1 株)、Lactobacillus pentosus(1 株)、Lactobacillus delbrueckii(1 株)、Lactococcus lactis(3 株)、Pediococcus pentosaceus(2 株)。结论:眉山泡菜中乳酸菌存在多样性,实验结果为工业发酵生产泡菜积累了菌株。  相似文献   

9.
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   

10.
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   

11.
Commercially prepared lamb was stored at −1.5 °C after inoculation with a combination of three Lactobacillus sakei strains previously shown to inhibit spoilage and pathogenic bacteria of importance to the meat industry. Between 6 and 14 weeks storage samples were evaluated for growth of inoculated strains, production of fermentation end-products and sensory acceptance of the cooked product. All three L. sakei strains flourished during storage, formed consistently dominant populations and were associated with lower surface pH and increased levels of lactic and acetic acids. Inoculated samples were determined to be as equally acceptable for smell, acidity, rancidity and overall liking as un-inoculated controls.  相似文献   

12.
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   

13.
 Caperberries (0.7–1.9 cm diameter), collected in June 1996, were pickled for 1 month in 5% and 10% brine. Some physical, chemical and microbiological analyses were made during their fermentation and storage. While lactic acid bacteria (LAB) increased during fermentation in 5% brine, they did not increase after 15 days in 10% brine. In some cases, total bacterial (TB) growth decreased. In both brines, yeasts/moulds and coliforms (except for 5% brine on day 15) were not present after 15 and 20 days, respectively. For both caper species, the most suitable salt concentration, for LAB activity was 5–10% NaCl, and the best length of fermentation with respect to product colour, flavour, acidity, pH and LAB activity in brine was 20–25 days. The texture was maintained well during storage. Acidity and pH were markedly affected by the concentration of brine. The quality of all samples was maintained with a 15% concentration of old or fresh brine during storage. The colour of the samples, especially those of C. ovata, stored with old brine was darker that of fresh berries. As no "off" flavour was observed, it was concluded that pickled caper berries can be stored in fresh brine with a 15% NaCl concentration.  相似文献   

14.
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   

15.
Lactic acid is the main acid produced during the Maotai liquor brewing process, influencing the quality of the base liquor and fermentation process. However, the microorganisms responsible for lactic acid production have not been identified. In this work, the dynamic changes in bacterial community structure in the Zaosha round (second sorghum feeding and fermentation) of the brewing process were analysed by 16S rRNA high‐throughput sequencing. Results show that lactic acid bacteria (LAB) and Bacillus spp. are the dominant bacteria in the brewing process, where Bacillus spp. are found in the early stage, whilst LAB are found throughout the brewing process. Furthermore, 10 types of LAB and five Bacillus spp. were isolated from Zaopei (a mixture of fermented grains including sorghum and wheat) by a culture‐dependent method. Lactobacillus panis accounts for 68% of the LAB, and Bacillus amyloliquefaciens for 54% of Bacillus spp. Solid‐state fermentation experiments were performed with L. panis and B. amyloliquefaciens and lactic acid production was consistent with the accumulation of lactic acid in Zaosha. The results showed that L. panis was the main producer of lactic acid in pits, while B. amyloliquefaciens plays an important role in the production of lactic acid in the early stages of fermentation. The approach used in this study may facilitate the identification of key microorganisms with specific functionality involved in other food and beverage fermentation processes. © 2018 The Institute of Brewing & Distilling  相似文献   

16.
Chouguiyu, or stinky mandarinfish, is a traditional Chinese fermented fish product made of mandarinfish by spontaneous fermentation at the anaerobic condition with low‐salt concentration. In order to get a primary understanding of the microbial community presenting in the Chouguiyu fermentation, 61 cultures of lactic acid bacteria (LAB) from various fermentation period were isolated using MRS agar plates and characterized based on a combination of phenotypic and genotypic approaches including amplified ribosomal DNA restriction analysis (ARDRA) and 16S rRNA partial gene sequencing analysis. Eight distinct bacterial species belonging to 6 genera were identified in total. Among them, Lactobacillus sakei was the dominant species (63%) during the fermentation, which exhibited great variety in phenotypic tests but unique genotypic characters. Meanwhile, the other LAB species including Lactococcus (Lc.) garvieae, Lc. lactis, Lc. raffinolactis, Vagococcus sp., Enterococcus hermanniensis, Macrococcus caseolyticus as well as Streptococcus parauberis were also recovered from the different fermentation periods, especially at the initial point of the fermentation. This seems to be the 1st report investigating the LAB composition involved in Chouguiyu fermentation and the data obtained in this study may be valuable for selecting starter culture for Chouguiyu industrial‐scale production.  相似文献   

17.
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   

18.
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   

19.
Starter cultures of lactic acid bacteria (Lactobacillus brevis, Lactobacillus cellobiosus, Lactobacillus fermentum, Lactobacillus plantarum and Pediococcus pentosaceus) and yeasts (Candida pelliculosa, Candida tropicalis, Issatchenkia orientalis and Saccharomyes cerevisiae) isolated from native togwa were tested singly or in combination for their ability to ferment maize-sorghum gruel to produce togwa. All species of bacteria showed an ability to ferment the gruel as judged by lowering the pH from 5.87 to 3.24-3.49 and increasing the titratable acidity from 0.08% to 0.30-0.44% (w/w, lactic acid) in 24 h. Yeasts used singly showed little activity within 12 h, but lowered the pH to 3.57-4.81 and increased the acidity to 0.11-0.21% in 24 h. Yeasts in co-culture with lactic acid bacteria (LAB) had a modest effect on the final acidity (P<0.05). The number of lactic acid bacteria and yeasts increased while the Enterobacteriaceae decreased with fermentation time. The pH was lowered and lactic acid produced significantly (P<0.05) fastest in natural togwa fermentation and in samples fermented by L. plantarum or L. plantarum in co-culture with I. orientalis. The content of fermentable sugars was reduced during fermentation. Most volatile flavour compounds were produced in samples from fermentation by P. pentosaceus and I. orientalis in co-culture with either L. plantarum or L. brevis.  相似文献   

20.
 Aerial parts of rock samphire (Crithmum maritimum L., Umbelliferae) growing along the seaside in Antalya and Mersin (southern Turkey) were randomly collected in June 1998. Flesh leaves and stems in 8% salt and 8% salt + 1% yogurt + 1% sugar (saccharose) were fermented for 25 days. Some chemical and microbiological analyses were made in brines during fermentation. The observed final product colour, flavour, odour, high acidity and lactic acid bacteria (LAB) activity, low pH, decreases fermentation time and lack of growth coliform bacteria after 10 days of fermentation indicated that the 8% salt + 1% yogurt + 1% sugar samples were superior to the 8% salt brines samples. The brine variety affected the final product quality more than the harvest region did. For both sampletypes, fermentation time was determined as 15 to 25 days with regard to end-product flavour and odour, brine acidity and pH, and LAB activity. Received: 12 April 1999  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