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1.
Several studies in recent years have shown the benefits deriving from the ingestion of probiotics, and a large number of products containing lactobacilli and bifidobacteria have been formulated. The purpose of this study was to develop a chocolate mousse to which probiotic and prebiotic ingredients were added, and verify the perspectives of the product with regard to potential for consumer health benefits and sensorial acceptance. Probiotic and synbiotic chocolate mousse supplemented with Lactobacillus paracasei subsp. paracasei LBC 82, solely (P) or together with the prebiotic ingredient inulin (S), were prepared, as well as a control mousse (C). The products were monitored for the population of L. paracasei and contaminants, during storage at 5 °C for up to 28 days, and sensory preference was also tested. Storage trials showed that the viability of the probiotic was retained over 28 days, but the growth of yeasts and moulds might limit the shelf-life of the product. Chocolate mousse was shown to be an excellent vehicle for the delivery of L. paracasei, and the prebiotic ingredient inulin did not interfere in its viability. Moreover, the addition of the probiotic microorganism and of the prebiotic ingredient did not interfere in the sensorial preference of the product.  相似文献   

2.
A rational selection of probiotic microorganisms is an important challenge and requires the definition of fundamental information about the physiology and genetics of candidate strains. In this study, selected Lactobacillus (Lact.) strains already characterized in a previous study for their capability to resist low pH and to grow in conditions simulating the intestinal environment, were further investigated to explore their probiotic properties, such as the adhesion capability to intestinal human Caco-2 cell lines and their growth behaviour in the presence of various prebiotic carbohydrates. At first 25 Lactobacillus strains were characterized by pulsed field gel electrophoresis using the endonuclease NotI. Among them, 13 strains belonging to the Lact. plantarum-group were identified at species level by a multiplex PCR assay. Subsequently 11 Lactobacillus strains showing different PFGE restriction pattern and the best acid- and bile-resistances, were chosen to investigate their in vitro adhesion capability to human intestinal epithelial cells and their fermentation properties of five prebiotic substances (FOS, Inulin, IMO, GOS and lactulose) at a concentration of 2%. The 11 strains analysed in this study possessed good adhesion capability to Caco-2 cell layers and, in particular, the eight strains belonging to the Lact. plantarum-group showed the higher final number of viable adhering cells. Moreover a species-related fermentative behaviour was pointed out and the strain Lact. paracasei EL7 was the only one able to grow in the presence of all prebiotics tested. In conclusion the strains of Lactobacillus studied in this research could be further investigated to assess possible in vivo human health benefits.  相似文献   

3.
Most clinical studies of probiotics use freeze-dried, powdered bacteria or bacteria packed in capsules. However, probiotics are commercially available in various food matrices, which may affect their persistence in the gastrointestinal tract. The objective of the study was to compare oral and faecal recovery during and after administration of a combination of Lactobacillus rhamnosus GG and LC705, Propionibacterium freudenreichii subsp. shermanii JS, and Bifidobacterium animalis subsp. lactis Bb12 as capsules, yoghurt, or cheese. This randomized, parallel-group, open-label trial (n = 36) included a 4-week run-in, 2-week intervention, and 3-week follow-up period. Participants consumed 1010 cfu/day of probiotic combination and provided saliva and faecal samples before, during, and after the intervention. Strain-specific real-time PCR was used to quantify the strains.L. rhamnosus GG was the only probiotic strain regularly recovered in saliva samples. During the intervention period it was recovered in the saliva of 88% of the volunteers at least once. No difference was found between the yoghurt and cheese groups. At the end of the intervention, L. rhamnosus GG and LC705 counts were high in faecal samples of all product groups (8.08 and 8.67 log10 genome copies/g, respectively). There was no matrix effect on strain quantity in faeces or the recovery time after ceasing the intervention. For P. freudenreichii subsp. shermanii JS and B. animalis subsp. lactis Bb12, a matrix effect was found at the end of the intervention (P < 0.01 and P < 0.001, respectively) and in the recovery time during follow-up (P < 0.05 for both). Yoghurt yielded the highest faecal quantity of JS and Bb12 strains (8.01 and 9.89 log10 genome copies/g, respectively). The results showed that the administration matrix did not influence the faecal quantity of lactobacilli, but affected faecal counts of propionibacteria and bifidobacteria that were lower when consumed in cheese. Thus, the consumption of probiotics in yoghurt matrix is highly suitable for studying potential health benefits and capsules provide a comparable means of administration when the viability of the strain in the capsule product is confirmed.  相似文献   

4.
A set of simple in vitro tests (identification by species-specific PCR, genetic diversity, phage sensitivity, growth and viability in milk, resistance to salts and flavor compounds, bacterial interactions, tolerance to simulated gastric juice and bile, bile salts deconjugation, hydrophobicity and β-galactosidase and antibacterial activities), that can be carried out in almost every laboratory of microbiology, mainly in developing countries where there is often limited access to sophisticated techniques, allowed us to identify, among 19 intestinal human isolates, a potential candidate for new probiotic dairy foods for the local market. Lactobacillus gasseri LgF37/1 performed well in the culture media used for the enumeration of probiotic bacteria in argentinian dairy products. This strain showed also high tolerance to the technological challenges assessed, bile salts resistance, the capacity to produce bacteriocin-like metabolites, to inhibit pathogenic bacteria, to deconjugate bile salts and high hydrophobicity. Further in vivo research should be carried out with this strain before claiming probiotic properties for it. However, the use of a set of simple in vitro techniques proved to be important to determine which strains should undergo future and more complex studies.  相似文献   

5.
The influence of two cheese-isolated Lactobacillus strains on cheese composition, acceptability and probiotic capacity was assessed. Soft cheeses with and without the addition of Lactobacillus plantarum I91 or Lactobacillus paracasei I90 were prepared. Gross composition was assessed and secondary proteolysis was described by soluble fractions and free amino acids profiles. Acceptability was determined by a panel of 98 non-trained consumers. Cheeses harboring added Lactobacillus strains were also studied in vivo to evaluate their probiotic capacity. Gross composition of the cheeses was similar for control and treated (Lactobacillus-added) cheeses. Peptidolysis increased in cheeses with added lactobacilli, which was evidenced by a higher free amino acid content. Overall, the acceptability of the cheeses was good: 65%–80% of the consumers said that they “liked very much” or “liked” the cheeses. Cheeses with L. plantarum I91 showed the highest changes in composition and proteolysis and were the most accepted ones. On the contrary, composition of cheeses with L. paracasei I90 was similar to that of the controls, but these samples were less accepted than cheeses without lactobacilli. The oral administration of cheese containing L. plantarum I91 or L. paracasei I90 proved to be safe and able to enhance the number of IgA + cells in the small intestine lamina propria of mice. The use of selected strains of NSLAB exerted a technological and probiotic role: it contributed to the standardization of cheese quality and induced benefic health effects at the gut mucosa in vivo.  相似文献   

6.
Fifteen strains of Lactobacillus and Bifidobacterium were screened based on their ability to adhere to hydrocarbons via the determination of cellular hydrophobicity. Lactobacillus acidophilus ATCC 314, L. acidophilus FTCC 0291, Lactobacillus bulgaricus FTCC 0411, L. bulgaricus FTDC 1311, and L. casei ATCC 393 showed greater hydrophobicity and, thus, were selected for examination of cholesterol-removal properties. All selected strains showed changes in cellular fatty acid compositions, especially total fatty acids and saturated and unsaturated fatty acids in the presence of cholesterol compared with those grown in the absence of cholesterol. In addition, we found that cells grown in media containing cholesterol were more resistant to sonication and enzymatic lysis compared with those grown without cholesterol. We further evaluated the location of the incorporated cholesterol via the insertion of fluorescence probes into the cellular membrane. In general, enrichment of cholesterol was found in the regions of the phospholipid tails, upper phospholipids, and polar heads of the cellular membrane phospholipid bilayer. Our results also showed that lactobacilli were able to reduce cholesterol via conversion of cholesterol to coprostanol, aided by the ability of strains to produce cholesterol reductase. Our results provided experimental evidence to strengthen the hypothesis that probiotics could remove cholesterol via the incorporation of cholesterol into the cellular membrane and conversion of cholesterol to coprostanol. The strains studied may be potential health adjunct cultures in fermented dairy products with possible in vivo hypocholesterolemic effects.  相似文献   

7.
C.N. Heenan  M.C. Adams  G.H. Fleet 《LWT》2004,37(4):461-466
Probiotic microorganisms were incorporated into a nonfermented, vegetarian frozen soy dessert at initial populations greater than 106 cfu/g. The product was assessed for the survival of probiotic microorganisms and sensory acceptability. Lactobacillus acidophilus MJLA1, L. rhamnosus 100-C, L. paracasei ssp. paracasei 01, Bifidobacterium lactis BBDB2, B. lactis BB-12 all survived the 6 month storage trial at populations of 107 cfu/g or greater. Saccharomyces boulardii 74012 did not retain sufficient viability, decreasing below the desirable level of 106 cfu/g. To detect sensory differences, product containing L. acidophilus MJLA1, S. boulardii 74012 and an uninoculated control were stored for 0, 4 and 7 months and compared using triangle tests. Product inoculated with L. acidophilus MJLA1 could not be distinguished from the control sample. Product with S. boulardii 74012 differed from the control and L. acidophilus MJLA1 and developed undesirable flavours during storage. The frozen soy dessert was a suitable food for the delivery of bacterial probiotic strains with excellent viability and acceptable sensory characteristics.  相似文献   

8.
The injuries caused by spray drying (SD) of three potential probiotic lactobacilli isolated from kefir grains and the impact on some probiotic properties, were evaluated. Results demonstrated that Lactobacillus plantarum 83114 and L. kefir 8321 showed a slight reduction of viability (0.11 and 0.29 log CFU/ml respectively) after SD process, and L. kefir 8348 was found to be more sensitive to the process with a reduction in viability of 0.70 log CFU/ml. Neither membrane damage, evaluated by increased sensitivity to NaCl, lysozyme, bile salt and penicillin G, nor changes in acidifying activity in MRS and milk by lactobacilli were detected after SD. L. plantarum 83114 and L. kefir 8321 after SD did not lose their capacity to adhere to intestinal cells. Nevertheless, L. kefir 8348 showed a significant loss of adhesion capacity after SD. In addition, rehydrated spray-dried L. kefir 8321 retained the ability to protect against Salmonella invasion of intestinal cells. This effect was observed when L. kefir is co-incubated with Salmonella before invasion assay.This work shows that the membrane integrity evaluated by indirect methods and some probiotic properties of lactobacilli isolated from kefir did not change significantly after SD, and these powders could be used in functional foods applications.  相似文献   

9.
Specific strains should only be regarded as probiotics if they fulfill certain safety, technological and functional criteria. The aim of this work was to study, from a comprehensive point of view (in vitro and in vivo tests), three Lactobacillus strains (Lactobacillus paracasei JP1, Lactobacillus rhamnosus 64 and Lactobacillus gasseri 37) isolated from feces of local newborns, determining some parameters of technological, biological and functional relevance. All strains were able to adequately grow in different economic culture media (cheese whey, buttermilk and milk), which were also suitable as cryoprotectants. As selective media, LP-MRS was more effective than B-MRS for the enumeration of all strains. The strains were resistant to different technological (frozen storage, high salt content) and biological (simulated gastrointestinal digestion after refrigerated storage in acidified milk, bile exposure) challenges. L. rhamnosus 64 and L. gasseri 37, in particular, were sensible to chloramphenicol, erythromycin, streptomycin, tetracycline and vancomycin, increased the phagocytic activity of peritoneal macrophage and induced the proliferation of IgA producing cells in small intestine when administered to mice. Even when clinical trails are still needed, both strains fulfilled the main criteria proposed by FAO/WHO to consider them as potential probiotics for the formulation of new foods.  相似文献   

10.
Lactobacilli are a major part of the microflora of the gut and of many fermented dairy products, and are found in a variety of environments. Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, and Lactobacillus zeae form a closely related taxonomic group within the facultatively heterofermentative lactobacilli. The classification and nomenclature of these bacteria are controversial. In this study, relationships between these species were investigated using type strains and dairy industry isolates examined with DNA-based techniques and conventional carbohydrate use tests. Carbohydrate use patterns gave poor discrimination of some species, but DNA PCR using specific primers targeted to sequences of the 16S rRNA gene discriminated 4 types consistent with the currently recognized species. Pulsed-field agarose gel electrophoresis of chromosomal NotI restriction fragments identified 18 different band patterns from 21 independent Lactobacillus isolates and confirmed the identity of L. casei strains from 2 culture collections (CSCC 5203 and ASCC 290), both representing the type strain of L. casei. Some isolates were reclassified as L. rhamnosus, suggesting that the prevalence of L. rhamnosus as a natural component of the microflora of dairy foods and dairy environments has previously been underestimated. These methods can provide a practical basis for discrimination of the species and identification of individual industrial strains.  相似文献   

11.
The work hypothesis of this paper was that during fermentation processes the chemico-physical interactions of the microbial metabolites with food matrix affects not only their retention, but the metabolic activity of the microorganisms. The influence of starch addition to liquid fermentation systems simulating sourdough and inoculated with pure and mixed population of Saccharomyces cerevisiae, Candida milleri and Lactobacillus sanfranciscensis significantly enhanced the production of selected metabolites. Moreover the starch addition interfered with the response of S. cerevisiae, C. milleri and L. sanfranciscencis when exposed to conditioned media of L. sanfranciscensis resulting in an increasing production of alcohols, isovaleric acid and of a key odorant like γ-decalactone. Under real conditions, the microstructure of the dough matrix significantly affected the metabolites production and cell activity.  相似文献   

12.
The production of volatile compounds by the probiotic strain, Lactobacillus plantarum NCIMB 8826, in cereal-based media (oat, wheat, barley and malt) was investigated. Sixty compounds, including fatty acids and their esters, amides, alcohols, aldehydes, aromatic hydrocarbons, furans, ketones, peroxides and pyrans, were identified. L. plantarum significantly changed the aroma profile of the four cereal broths, and each substrate showed a specific volatiles profile. Oat and barley media were the substrates more influenced by the fermentation process. The most abundant volatiles detected in oat, wheat, barley and malt were oleic acid, linoleic acid, acetic acid, and 5-hydroxymethylfurfural, respectively. Analysis of these products confirmed the heterofermentative pathway of L. plantarum. Maillard compounds were not detected during sterilisation and fermentation. This study is the first to report the volatile composition of probiotic drinks produce with non-supplemented cereal-based media and the results obtained could contribute to the development of new non-dairy probiotic formulations.  相似文献   

13.
Lactic acid bacteria (LAB) antimicrobial peptides typically exhibit antibacterial activity against food-borne pathogens, as well as spoilage bacteria. Therefore, they have attracted the greatest attention as tools for food biopreservation. In some countries LAB are already extensively used as probiotics in food processing and preservation. LAB derived bacteriocins have been utilized as oral, topical antibiotics or disinfectants. Lactobacillus salivarius is a promising probiotic candidate commonly isolated from human, porcine, and avian gastrointestinal tracts (GIT), many of which are producers of unmodified bacteriocins of sub-classes IIa, IIb and IId. It is a well-characterized bacteriocin producer and probiotic organism. Bacteriocins may facilitate the introduction of a producer into an established niche, directly inhibit the invasion of competing strains or pathogens, or modulate the composition of the microbiota and influence the host immune system. This review gives an up-to-date overview of all L. salivarius strains, isolated from different origins, known as bacteriocin producing and/or potential probiotic.  相似文献   

14.
In the study, the ability of two potentially probiotic strains Lactobacillus plantarum 14 and Lactobacillus fermentum 4a to milk fermentation and the possibility to use them in yogurt production were investigated. The strains did not acidify milk during 24 h and 72 h fermentation at 37C, but grew well and remained at the level of 108 colony-forming units (CFU)/mL during 21 days of cold storage. Their application to yogurt production along with commercial starter culture consisted on L. delbrueckii ssp. bulgaricus and S. thermophilus allowed to obtain products with typical sensory properties, pH values and numbers of potentially probiotic bacteria at desired level 107 CFU/mL.  相似文献   

15.
The growth of six probiotic commercial strains of lactobacilli was assessed in reconstituted dried whey and buttermilk supplemented with yeast extract, meat peptone, soy peptone, tryptone or casein acid hydrolysate at 0.3%, 0.6% or 1%. The addition of 1% glucose was also tested. Growth and acidification kinetics were determined at 37°C using MRS broth and a commercial culture medium as references. The suitability of whey and buttermilk as cryoprotectants at –20°C and –70°C was also assessed. Whey and buttermilk with 0.3% yeast extract were chosen for the growth of probiotic lactobacilli, since no satisfactory growth was observed without an external nitrogen source, whereas glucose did not improve the growth of any of the strains assayed. In general, buttermilk performed as satisfactorily as the reference media. The effectiveness of these media as cryoprotectants was strain dependent: skimmed milk and whey were the most suitable ones, especially for long-term storage at –20°C. However, at –70°C, no significant differences were observed between the culture media assessed. The use of whey or buttermilk as culture media for the production of probiotic lactic acid bacteria and for their cryopreservation implies a novel use of these low-cost products, offering an alternative way of utilizing the by-products of the dairy industry, helping to minimize their negative impact on the environment.  相似文献   

16.
Resistance to gastrointestinal conditions is a requirement for bacteria to be considered probiotics. In this work, we tested the resistance of six different Lactobacillus strains and the effect of carbon source to four different gastrointestinal conditions: presence of α-amylase, pancreatin, bile extract and low pH. Novel galactooligosaccharides synthesized from lactulose (GOS-Lu) as well as commercial galactooligosaccharides synthesized from lactose (GOS-La) and lactulose were used as carbon sources and compared with glucose. In general, all strains grew in all carbon sources, although after 24 h of fermentation the population of all Lactobacillus strains was higher for both types of GOS than for glucose and lactulose. No differences were found among GOS-Lu and GOS-La. α-amylase and pancreatin resistance was retained at all times for all strains. However, a dependence on carbon source and Lactobacillus strain was observed for bile extract and low pH resistance. High hydrophobicity was found for all strains with GOS-Lu when compared with other carbon sources. However, concentrations of lactic and acetic acids were higher in glucose and lactulose than GOS-Lu and GOS-La. These results show that the resistance to gastrointestinal conditions and hydrophobicity is directly related with the carbon source and Lactobacillus strains. In this sense, the use of prebiotics as GOS and lactulose could be an excellent alternative to monosaccharides to support growth of probiotic Lactobacillus strains and improve their survival through the gastrointestinal tract.  相似文献   

17.
The objective of this study was to monitor the viability during storage of Lactobacillus acidophilus LA-5 (A), Bifidobacterium animalis ssp. lactis BB-12 (B), and Streptococcus thermophilus CHCC 742/2130 (T) in probiotic cultured dairy foods made from pasteurized camel, cow, goat, and sheep milks fermented by an ABT-type culture. The products manufactured were stored at 4°C for 42 d. Microbiological analyses were performed at weekly intervals. Streptococcus thermophilus CHCC 742/2130 was the most numerous culture component in all 4 products both at the beginning and at the end of storage. The viable counts of streptococci showed no significant decline in fermented camel milk throughout the entire storage period. The initial numbers of Lb. acidophilus LA-5 were over 2 orders of magnitude lower than those of Strep. thermophilus CHCC 742/2130. With the progress of time, a slow and constant decrease was observed in lactobacilli counts; however, the final viability percentages of this organism did not differ significantly in the probiotic fermented milks tested. The cultured dairy foods made from cow, sheep, and goat milks had comparable B. animalis ssp. lactis BB-12 counts on d 0, exceeding by approximately 0.5 log10 cycle those in the camel milk-based product. No significant losses occurred in viability of bifidobacteria in fermented camel, cow, and sheep milks during 6 wk of refrigerated storage. In conclusion, all 4 varieties of milk proved to be suitable raw materials for the manufacture of ABT-type fermented dairy products that were microbiologically safe and beneficial for human consumption. It was suggested that milk from small ruminants be increasingly used to produce probiotic fermented dairy foods. The development of camel milk-based probiotic cultured milks appears to be even more promising because new markets could thus be conquered. It must be emphasized, however, that further microbiological and sensory studies, technology development activities, and market research are needed before such food products can be successfully commercialized.  相似文献   

18.
Electroporation enhances the ability of lactobacilli to remove cholesterol   总被引:1,自引:0,他引:1  
The objective of the present study was to evaluate the effect of electroporation on the membrane properties of lactobacilli and their ability to remove cholesterol in vitro. The growth of lactobacilli cells treated at 7.5 kV/cm for 4 ms was increased by 0.89 to 1.96 log10 cfu/mL upon fermentation at 37°C for 20 h, the increase being attributed to the reversible and transient formation of pores and defragmentation of clumped cells. In addition, an increase of cholesterol assimilation as high as 127.2% was observed for most cells electroporated at a field strength of 7.5 kV/cm for 3.5 ms compared with a lower field strength of 2.5 kV/cm. Electroporation also increased the incorporation of cholesterol into the cellular membrane, as shown by an increased cholesterol:phospholipids ratio (50.0–59.6%) upon treatment at 7.5 kV/cm compared with treatment at 2.5 kV/cm. Saturation of cholesterol was observed in different regions of the membrane bilayer such as upper phospholipids, apolar tail, and polar heads, as indicated by fluorescence anisotropy using 3 fluorescent probes. Electroporation could be a useful technique to increase the ability of lactobacilli to remove cholesterol for possible use as cholesterol-lowering adjuncts in the future.  相似文献   

19.
Different species of Lactobacillus involved in dairy product fermentation and ripening were considered in order to study the effect of high pressure homogenization (HPH) on: (i) fermentation kinetics of HPH treated cells inoculated in milk; (ii) metabolic profiles; (iii) release of intracellular proteolytic enzymes; and (iv) enhance of the activity of extracellular or cellular wall located proteolytic enzymes. The HPH treatments applied were 50, 100, 150 MPa, 2 cycles at 50 and at 100 MPa. The viability loss did not exceed 1.3 log cfu/ml after the higher treatments applied. The electrophoretic profiles of α- or β-casein incubated with the different cell free filtrates shown that HPH positively affected the proteolytic activity of some strains. Moreover, HPH affected the acidification rates of the milk inoculated with the processed cells and the primary metabolism of some strains. Regarding volatile compounds, ethanol, acetoin and 2-methyl butyric acid were subjected to the major changes when the inoculum had been processed.  相似文献   

20.
The characterisation of 24 lactic acid bacteria (LAB) isolates from Nigerian traditional fermented dairy foods, including some cow's intestine isolates, was conducted in order to select isolates for potential use as probiotics. LAB isolates were identified by partial sequencing the 16S rRNA gene as belonging to the species Lactobacillus paracasei, Lactobacillus brevis and mainly Weissella confusa. At the end of a characterisation process, 2 L. paracasei and 2 W. confusa isolates were selected, and their resistance to a simulated gastrointestinal digestion and their ability to adhere to eukaryotic cell lines were assessed. The survival to the simulated gastrointestinal passage was higher when bacterial suspensions were made in skimmed milk (2.0 ± 0.8 log units reduction) or at the simulated gastric juice pH 3 (2.7 ± 0.9 log units reduction) than at pH 2.0 (5.5 ± 0.7 log units reduction). Adhesion of LAB to both intestinal and vaginal epithelial models was comparable or higher than that of the reference Lactobacillus rhamnosus GG. However, some of the isolates increased the adhesion of the pathogen Escherichia coli LMG2092 to HT-29 and HeLa monolayers. Overall, isolates L. paracasei UI14 and W. confusa UI7 are good candidates for further studying potential benefits that support their use as probiotics. This is one of the few articles reporting the characterisation and the probiotic potential of Weissella, although more studies are needed in order to establish their safety for potential probiotic applications.  相似文献   

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