Enrichment of bioactive isoflavones in soymilk fermented with β-glucosidase-producing lactic acid bacteria

This study was undertaken to investigate the possible application of β-glucosidase-producing lactic acid bacteria as a functional starter cultures to obtain the bioactive isoflavones, genistein and daidzein, in fermented soymilk. Four strains – Lactobacillus plantarum KFRI 00144, Lactobacillus delbrueckii subsp. lactis KFRI 01181, Bifidobacterium breve K-101 and Bifidobacterium thermophilum KFRI 00748 – among the 31 lactic acid bacteria tested for β-glucosidase activity using ρ-nitrophenyl-β-d-glucopyranoside as the substrate were selected. Acid development, viable populations, and quantification of isoflavones using HPLC were performed at 0, 24, and 48 h of incubation at 37 °C. The significant bioconversion (P < 0.001) of the glucoside isoflavones into their bioactive aglycones in soymilk fermented with four β-glucosidase-producing strains, with an average 7.1-fold increase of aglycones (daidzein + genistein) was observed. There appeared to be correlations between the level of growth and β-glucosidase activity of each strain, and the hydrolysis of conjugated isoflavones in soymilk fermentation. Lactobacillus sp. were able to readily proliferate in soymilk than Bifidobacterium sp. (P < 0.05) and therefore completed more rapidly the hydrolysis of glucoside isoflavones.The present study indicates that four β-glucosidase-producing lactic acid bacteria have great potential for the enrichment of bioactive isoflavones in soymilk fermentation.     

Effect of Lactobacillus-fermented adlay-based milk on lipid metabolism of hamsters fed cholesterol-enriched diet

The aim of this study was to investigate the effect of adlay milk and adlay-soymilk fermented with Lactobacillus plantarum or Lactobacillus paracasei on lipid metabolism in hamsters fed with a cholesterol-enriched diet. Adlay milk and fermented adlay milk with or without soymilk administered to hamsters significantly decreased (p < 0.05) serum cholesterol levels and ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol, when compared to a high-cholesterol diet group; there was also a significant (p < 0.05) increase in the level of fecal cholesterol and triglycerides. The group administered adlay milk fermented with L. plantarum or L. paracasei presented increased superoxide dismutase and total antioxidant status activity in the blood, thus relieving the levels of thinobarbituric acid reactive substances as compared to other treatment groups. Adlay milk and Lactobacillus-fermented adlay milk with or without a soymilk supplement, could be used as a potential cholesterol-lowering ingredient; it could also relieve hyperlipidemia-induced oxidative stress to improve hypercholesterolemia.     

Effect of Lactobacillus plantarum on the survival of acid‐tolerant non‐O157 Shiga toxin‐producing E. coli (STEC) strains in fermented goat's milk

The ability of goat's milk fermented with a Lactobacillus plantarum strain B411, and in combination with commercial starter culture, to inhibit acid‐adapted (AA) and non‐acid‐adapted (NAA) environmental non‐O157 STEC strains was investigated. Acid‐adapted and NAA non‐O157 STEC strains were not inhibited in the L. plantarum‐fermented goat's milk, while the goat's milk fermented with the combination of L. plantarum and starter culture inhibited AA more than NAA non‐O157 STEC strains. Environmental acid‐tolerant non‐O157 STEC strains were not inhibited by L. plantarum, starter culture or combination of starter culture with L. plantarum unless they were subjected to prior acid adaptation such as backslopping.     

Effects of different coagulants on coagulation behavior of acid-induced soymilk

Divalent calcium ions can be used into the coagulation procedure of tofu-producing. The different calcium salts also have the difference coagulation process. This paper reports an investigation on the effects of counterions of calcium salts on the coagulation process of soymilk protein by the variation of viscosity. The same amount of Lactobacillus plantarum 70810 was added because of its acid reduction effects, which plays a synergistic effect with calcium salts. Coagulation process of soymilk containing various coagulants was characterized by viscosity under a shear rate of 2 s⁻¹ at 37 °C. The textural properties and pH of tofu prepared from different coagulants were also determined. Results indicated that there are two successive first-order reactions by viscosity analysis, and the coagulation rate constant in the second stage was 4–6 times higher than that the first stage. The coagulation rate among the coagulants followed the anion series: formate > acetate > chloride > lactate. The textural properties also have correlation with the final viscosity of soybean milk mixture after 4.5 h coagulation, whereas the pH has nothing to do with the coagulants behaved. Evidence emerged that counterions of calcium source salts affect the coagulation process of soymilk protein. This fact clearly opens up many possibilities for soymilk coagulation.     

Effects of oligosaccharides on the fermentation properties of Lactobacillus plantarum

In the present work, we studied the effects of different oligosaccharides on Lactobacillus plantarum ATCC14917, focusing on growth and adhesion characteristics and fermented milk flavor. The results showed that mannan-oligosaccharide (MOS) had the greatest proliferative effect on L. plantarum ATCC14917 in vitro. In terms of adhesive properties, the autoaggregation rate of L. plantarum cultured in MOS was 23.76%, adhesion to mucin was 24.65%, and adhesion to Caco-2 cells was 14.71%. These results for L. plantarum cultured with MOS were higher than those for L. plantarum cultured in fructo-oligosaccharides (FOS) or galacto-oligosaccharides (GOS). Furthermore, the surface consistency and viscosity scores of fermented milk of the MOS group was higher than that of milks cultured with FOS or GOS, although MOS had the lowest scores for fermented milk flavor.     

Influence of Lactobacillus plantarum on yogurt fermentation properties and subsequent changes during postfermentation storage

This study aimed to evaluate the influence of 9 Lactobacillusplantarum with broad-spectrum antibacterial activity on fermented milk, including changes to the fermentation characteristics (pH, titration acidity, and viable counts), texture profile, relative content of volatile compounds, and sensory evaluation during 28-d storage at 4°C. First, L. plantarum IMAU80106, IMAU10216, and IMAU70095 were selected as candidates for further study because of their excellent coagulation and proteolytic activities. Subsequently, these L. plantarum strainswere supplemented to fermented milk produced by commercial yogurt starters (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) and a panel of parameters reflecting product quality was subsequently monitored during 28 d of postfermentation storage. The pH value and titration acidity of the fermented milk mildly fluctuated, whereas the L. plantarum viable counts remained stable along the storage period. Fourteen key volatile compounds were detected in the fermented milk by gas chromatography-mass spectrometry, and some flavor compounds were uniquely present in the L. plantarum-supplemented fermented milk (including 2,3-pentanedione, acetaldehyde, and acetate). No significant difference was shown in the sensory evaluation scores between samples with or without L. plantarum supplementation, but a gradual decrease was observed over storage in all samples. However, when L. plantarum was added, apparent shifts were observed in the overall quality of the fermented milk based on principal component analysis and multivariate ANOVA, particularly in the texture (adhesiveness) and volatile flavor compound profiles (acetaldehyde). Compared with L. plantarum IMAU80106 and IMAU10216, both the texture and volatile flavor profiles of IMAU70095 were closest to those of the control without adding the adjunct bacteria, suggesting that IMAU70095 might be the most suitable strain for further application in functional dairy product development. The current work has explored the potential of applying L. plantarum in fermented milk by performing thorough physical and chemical characterization. Our work is of intense interest to the dairy industry.     

Isolation and identification of high viscosity-producing lactic acid bacteria from a traditional fermented milk in Xinjiang and its role in fermentation process

Forty-four lactic acid bacteria (LAB) isolated from traditional Sayram ropy fermented milk (SRFM) in southern Xinjiang of China. Further two strains were selected based on their high viscosity-producing activity. Based on the API 50 CHL strip and 16S rDNA sequence analysis, strain MB 2-1 was a Gram-positive, rod-shaped Lactobacillus helveticus and strain MB 5-1 was identified as Streptococcus thermophilus. Both the two LAB strains were grown in the milk fermentations for pure and mixed cultures and were evaluated for their growth, acidification properties, EPS production, and ability to increase the apparent viscosity of fermented milk, respectively. L. helveticus MB 2-1 displayed a high increasing in viable cell counts and the acidifying capacity in pure cultures, whereas the relatively high EPS production and viscosity-producing capacity detected in pure culture with S. thermophilus MB 5-1 as starter culture. In addition, the mixed culture of the two strains showed a higher cell growth, EPS production, and high viscosity-producing capacity at 37?°C. Values of apparent viscosity were 4.03- and 2.41-fold higher in mixed culture than for pure cultures of L. helveticus MB 2-1 and S. thermophilus MB 5-1, respectively. There was a positive correlation between the viscosity and high molecular weight EPS production with pure and mixed cultures. Our data showed two strains combination, with high viscosity-producing and acidifying capacity, can be used in mixed cultures for the manufacture of fermented milk with improved functional properties.     

Influence of native lactic acid bacteria on the microbiological,biochemical and sensory profiles of Serra da Estrela cheese

Cheesemaking from batches of raw ewe's milk was carried out via inoculation with wild strains of Lactococcus lactis subsp. lactis ESB110019 and Lactobacillus plantarum ESB5004 independently, or combined with each other. Those two strains had been isolated from the native microflora of typical Serra da Estrela cheese. One control batch was processed in parallel without addition of any starter. The evolution in viable counts of the main micro-organisms (viz. lactic acid bacteria, Enterobacteriaceae, staphylococci and yeasts), as well as in secondary proteolysis (WSN, 2% TCASN, 12% TCASN and 5% PTASN), was monitored throughout ripening time (over a 63-day period) in cheeses from each batch. The sensory features of the fully ripened cheeses were also assessed. Cheeses manufactured with starter showed significantly lower levels of viable Enterobacteriaceae than those manufactured without starter; viable counts of enterococci and staphylococci did significantly increase after addition of L. lactis or Lb. plantarum, respectively. Proteolysis in terms of WSN and 5% PTASN was not significantly affected by the lactic acid bacteria tested when compared to the control, but L. lactis played a significant role toward increasing the 2% TCASN content of cheeses; both strains led to a statistically significant increase of the 12% TCASN. The scores for flavor and texture of the control cheeses were somewhat above those for the experimental cheeses manufactured with starter.     

Isolation and identification of an exopolysaccharide-producing lactic acid Bacterium strain from Chinese Paocai and biosorption of Pb(II) by its exopolysaccharide

Lactic acid bacteria isolated from various traditional Chinese fermented foods were screened for the production of exopolysaccharides (EPS). The strain 70810 from Chinese Paocai, which was identified as Lactobacillus plantarum (HQ259238) by morphological, physiological, biochemical, and 16S rDNA tests, was selected due to its highest EPS production capability (0.859 g/L) for further study. Biosorption of Pb(II) from aqueous solutions by 70810 EPS was studied with parameters of initial pH, contact time, initial Pb(II) concentration, adsorbent dosage, and temperature, respectively. Maximum adsorption of Pb(II) was observed at pH 5, 30 °C, and 6 h, respectively. The adsorption capacity was also found to be dependent upon initial Pb(II) concentration and adsorbent dosage. Surface adsorption of the metal at surface of 70810 EPS was confirmed through scanning electron microscopy. Fourier transform infrared spectroscopy spectra analysis indicated that some functional groups (for example, -OH, COO-, C = O, and -NH) of 70810 EPS were involved in Pb(II) biosorption process. PRACTICAL APPLICATION: Lactobacillus plantarum 70810 can be used as a starter culture for the production of some fermented foods (for example, yoghurt or fermented soybean milk) and the production of EPS that can meet consumer's demand for products with low levels of additives. The EPS may be used as a potential biosorbent for the removal of heavy metal from environment and these fermented foods maybe have the potential effect to excrete lead from human body.     

Effect of Synbiotic Interaction of Fructooligosaccharide and Probiotics on the Acidification Profile, Textural and Rheological Characteristics of Fermented Soy Milk

Preparation of yoghurt-like product from non-dairy raw material, such as soy with probiotic and prebiotic is a novel development in the field of fermented functional foods. This research work aimed at finding the new combinations of probiotics Lactobacillus acidophilus, Lactobacillus plantarum and Lactobacillus rhamnosus, which can give good product characteristics to fermented soy milk. Fructooligosaccharide was added in an attempt to reduce the after-taste of soymilk, improve acidification rates and growth of probiotics. Acidification rate was enhanced with L. acidophilus–L. plantarum and L. acidophilus–L. plantarum–L. rhamnosus, resulting in a shorter time to reach pH 4.5. Hardness was significantly (P?<?0.05) higher for soy yoghurt fermented by binary co-culture followed by mixed cultures. All the samples showed higher G′ (1,279.70–1405 Pa) and lower tan δ (0.273–0.346) values which signifies firmer and solid-like character of the gel formed by probiotic bacteria. Soy yoghurt made with L. acidophilus–L. plantarum resulted in improved product characteristics with shorter t _pH 4.5 (4.28 h). Soy yoghurt fermented with L. acidophilus–L. plantarum showed more than 9 log cfu/ml count which is required for probiotic functional food.     

植物乳杆菌ST-Ⅲ在豆乳中的发酵特性及发酵豆乳的贮藏稳定性

通过测定植物乳杆菌ST-Ⅲ在发酵豆乳过程中的生长曲线、酸化曲线、蛋白水解能力和豆乳表观黏度、终产品感官分值,以及发酵豆乳在不同贮藏温度下植物乳杆菌ST-Ⅲ菌数、pH值、持水力和感官变化,研究植物乳杆菌ST-Ⅲ在豆乳中的发酵特性和发酵豆乳产品的贮藏稳定性。结果显示,植物乳杆菌ST-Ⅲ在豆乳中生长良好,到达发酵终点时的菌数为6.1×108 CFU/mL(对数值为8.78),表观黏度可达0.24Pa·s,感官品质较佳;发酵豆乳在低温(4℃)条件下各指标变化差异较小,贮藏稳定性明显优于常温(25℃)时。表明植物乳杆菌ST-Ⅲ具有发酵豆乳制品的优势与潜力。     

Impact of fermentation conditions and refrigerated storage on microbial quality and biogenic amine content of sauerkraut

White cabbage (Brassica oleracea L. var. capitata cv. Bronco) was fermented, at 0.5% and 1.5% NaCl, using Lactobacillus plantarum or Leuconostoc mesenteroides as starter cultures and, subsequently, sauerkraut was stored at 4 °C for 3 months. Microbial populations and six biogenic amines (putrescine, cadaverine, histamine, tyramine, spermine and spermidine) were investigated. Fermentation and storage increased aerobic mesophilic bacteria and LAB populations in sauerkrauts, and this was accompanied by a rise in biogenic amine content. L. plantarum sauerkrauts produced with 0.5% NaCl had the highest microbial counts, whilst no differences between salt contents were found with L. mesenteroides. Total biogenic amine amount was lower at 0.5% NaCl than at 1.5% in both induced fermentations and L. mesenteroides produced a lower content than did L. plantarum. Spermidine was the major contributor to the total biogenic amine content, followed by putrescine, whilst histamine was present at the lowest level. The individual and total biogenic amine levels in the experimental sauerkrauts stored at 4 °C for 3 months were below the upper limits reported in the literature for fermented products, indicating good quality and safety of the sauerkrauts. L. mesenteroides starter and 0.5% NaCl were the optimal fermentation conditions for producing sauerkrauts with the lowest biogenic amine contents.     

Effect of selected autochthonous starter cultures on processing and quality characteristics of Greek fermented sausages

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.     

Lactobacillus pentosus dominates spontaneous fermentation of Italian table olives

Culture-dependent and -independent approaches were applied to identify the bacterial species involved in Italian table olive fermentation. Bacterial identification showed that Lactobacillus pentosus was the dominant species although the presence of Lactobacillus plantarum, Lactobacillus casei, Enterococcus durans, Lactobacillus fermentum and Lactobacillus helveticus was observed. Rep-PCR allowed to obtain strain-specific profiles and to establish a correlation with table olive environment. PCR-DGGE (Denaturing Gradient Gel Electrophoresis) confirmed the heterogeneity of bacterial community structure in fermented table olives as well as the prevalence of L. pentosus. The strains were characterized on the basis of technological properties (NaCl tolerance, β-glucosidase activity and the ability to grow in synthetic brine and in presence of 1 g/100 mL oleuropein). L. pentosus showed a high capacity of adaptation to the different conditions characterizing the olive ecosystem. This species showed the highest percentage of strains able to grow in presence of 10 g/100 mL NaCl, oleuropein and in the synthetic brine. Moreover, all the strains belonging to L. pentosus and L. plantarum species showed a β-glucosidase activity. This study allowed both to identify the main species and strains associated to Italian table olives and to obtain a lactic acid bacteria collection to apply as starter culture in the process of olive fermentation.     

Synergistic effects of combinatorial Lactiplantibacillus plantarum fermentation and vegetable oils supplementation on the lycopene level,antioxidant capacities and flavor volatiles of tomato pulp

The objective of this study was to investigate the effects of Lactiplantibacillus plantarum (L. plantarum) fermentation and three types of vegetable oils (corn oil, peanut oil, and olive oil) supplementations on the physicochemical properties, bioactive components, and flavor volatiles of tomato pulp. Tomato pulp supplemented with oils was excellent food matrices for L. plantarum growth, and the colony counts remained above 8.3 log CFU/mL at the end of fermentation. The contents of total phenol, carotenoids and lycopene were dramatically increased after fermentation, and oils supplementation exhibited a synergistic promotion effect, especially for the combination of L. plantarum fermentation and 3% olive oil supplementation exhibiting the highest lycopene level (30 mg/mL), the strongest DPPH radical scavenging activity (84.24%) and FRAP (16.45 mmol Trolox/L). Furthermore, synergistic L. plantarum fermentation and oils supplementation decreased aldehydes content, and increased alcohols, esters, and ketones formation, meaning the improved flavor characteristics of fermented tomato pulp.Industrial relevanceIn this study, a functional beverage of tomato pulp was prepared by the combination of L. plantarum fermentation and vegetable oils supplementation. Colony counts, lycopene level, antioxidant capacities, and flavor characteristics were dramatically improved at the end of fermentation. This study provides an innovative technology to improve the release of lycopene from plant tissue and provide a functional beverage of tomato pulp with high health benefits.     

Physicochemical,textural and volatile characteristics of fermented milk co-cultured with Streptococcus thermophilus,Bifidobacterium animalis or Lactobacillus plantarum

Fermented milks were prepared with various culture combinations of Lactobacillus plantarum or Bifidobacterium animalis with Streptococcus thermophilus, and the impact of microbes combinations on acidification, proteolysis, lipolysis, texture, volatiles and sensory quality of fermented milk was investigated during 21-day storage at 4 °C. The results showed that products from the co-cultures displayed higher titratable acidity, more peptides, higher proteolytic activity and lipolysis capacity compared with that from the pure strains of S. thermophilus. When L. plantarum and B. animalis combined in a ratio of 2:1 with S. thermophilus, the products maintained relatively more viable cell counts of the 3 strains, strong proteolysis ability and lipolysis capacity during the storage. Milk fermented by co-cultures of the 3 strains exhibited higher cohesiveness, more volatiles and better sensory quality compared with these fermented by S. thermophilus only or in co-cultures with either B. animalis or L. plantarum based on principal component analysis.     

Isolation and characterization of acid-sensitive Lactobacillus plantarum with application as starter culture for Nham production

The aim of this study was to derive new starter culture variants that are unable to grow below pH 4.6, the desirable pH of the Thai fermented pork sausage, Nham, specified by Thailand Food Standard, and apply them in Nham fermentation. Several acid-sensitive mutants of one of the commercial Nham starter cultures, Lactobacillus plantarum BCC 9546, were isolated as spontaneous neomycin-resistant mutants. The growth of three representative mutants was characterized in MRS broth, which revealed that their cell numbers and acid production were lower than that of the wild-type. The H⁺-ATPase activities of the three mutants were found significantly lower than that of the wild-type under either neutral or acidic conditions. Consequently, internal pH values of the mutants appeared to be lower, especially in acidic environment (pH 5). The most acid-sensitive mutant was applied in experimental Nham production and the pH of Nham fermented with the mutant had significantly higher pH at the end of fermentation (3 days) and after an additional 4 days of storage at 30 °C. These results indicate that the use of acid-sensitive L. plantarum as starter culture can reduce the severity of post-acidification and increase the shelf life of Nham at ambient temperature.     

Use of a starter culture of lactic acid bacteria in plaa-som, a Thai fermented fish

Plaa-som is a Thai fermented fish prepared from freshwater fish and various ingredients. In this study, two strains of lactic acid bacteria (LAB) isolated from natural plaa-som fermentation were used as starter cultures: Lactobacillus plantarum IFRPD P15 and Lactobacillus reuteri IFRPD P17. These strains were used as a mixed starter culture for plaa-som using an air-drying method (laminar airflow) with sterilized rice grains as the filler. This method produced a suitable starter culture, which was maintained at 4 °C for more than 20 weeks. LAB were the dominant bacteria in the starter culture and produced high acidity from 24 h until the end of fermentation. This resulted in decreased pH in plaa-som. L. plantarum IFRPD P15 was dominant as an acidity producer, whereas L. reuteri IFRPD P17 showed an ability to suppress and eliminate pathogenic bacteria such as Escherichia coli within 24 h. The use of a single starter culture for plaa-som resulted in incomplete suppression of pathogenic bacteria and elimination of E. coli. Thus, L. plantarum IFRPD P15 and L. reuteri IFRPD P17 have great potential for use as a mixed starter culture in plaa-som fermentation and may possibly help to reduce fermentation time.     

Selection of Lactobacillus plantarum strains to use as starters in fermented table olives: Oleuropeinase activity and phage sensitivity

Fermented table olives (Olea europaea L.) are largely diffused in the Mediterranean area. Olives are picked at different stages of maturity and after harvesting, processed to eliminate the characteristic bitterness caused by the presence of the oleuropein glucoside and to become suitable for human consumption. The spontaneous fermentation of table olives mainly depends on lactic acid bacteria (LAB), and in particular on Lactobacillus plantarum which plays an important role in the degradation of oleuropein. The hydrolysis of oleuropein is attributed to the β-glucosidase and esterase activities of the indigenous LAB microflora. This study investigated the potential of L. plantarum strains isolated from dairy products and olives to be used as starters for fermented table olives. Forty-nine strains were typed by RAPD-PCR and investigated for the presence of the β-glucosidase (bglH) gene. The full sequence of the bglH gene was carried out. All the 49 L. plantarum strains were also tested for phage resistance. A total of six strains were selected on the basis of genotypic polymorphism, bglH gene sequence analysis, and phage resistance profile. These strains were further characterized to assess the acidifying capability, the growth at different temperatures, the tolerance to different NaCl concentrations, and the oleuropeinolytic activity. Although further characterizations are required, especially concerning the influence on sensory properties, L. plantarum proved to have the potential to be used as a debittering and fermentative agent in starter culture for fermented table olives.     

Production of exopolysaccharides by Lactobacillus and Bifidobacterium strains of human origin, and metabolic activity of the producing bacteria in milk

This work reports on the physicochemical characterization of 21 exopolysaccharides (EPS) produced by Lactobacillus and Bifidobacterium strains isolated from human intestinal microbiota, as well as the growth and metabolic activity of the EPS-producing strains in milk. The strains belong to the species Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus plantarum, Lactobacillus vaginalis, Bifidobacterium animalis, Bifidobacterium longum, and Bifidobacterium pseudocatenulatum. The molar mass distribution of EPS fractions showed 2 peaks of different sizes, which is a feature shared with some EPS from bacteria of food origin. In general, we detected an association between the EPS size distribution and the EPS-producing species, although because of the low numbers of human bacterial EPS tested, we could not conclusively establish a correlation. The main monosaccharide components of the EPS under study were glucose, galactose, and rhamnose, which are the same as those found in food polymers; however, the rhamnose and glucose ratios was generally higher than the galactose ratio in our human bacterial EPS. All EPS-producing strains were able to grow and acidify milk; most lactobacilli produced lactic acid as the main metabolite. The lactic acid-to-acetic acid ratio in bifidobacteria was 0.7, close to the theoretical ratio, indicating that the EPS-producing strains did not produce an excessive amount of acetic acid, which could adversely affect the sensory properties of fermented milks. With respect to their viscosity-intensifying ability, L. plantarum H2 and L. rhamnosus E41 and E43R were able to increase the viscosity of stirred, fermented milks to a similar extent as the EPS-producing Streptococcus thermophilus strain used as a positive control. Therefore, these human EPS-producing bacteria could be used as adjuncts in mixed cultures for the formulation of functional foods if probiotic characteristics could be demonstrated. This is the first article reporting the physicochemical characteristics of EPS isolated from human intestinal microbiota.