The Differences in Protein Degradation and Sensitization Reduction of Mangoes between Juices and Pieces Fermentation.

Given the allergic reaction caused by mangoes, nonthermal food technologies for allergenicity reduction are urgently desired. This study aimed to assess the impact of kombucha fermentation on the allergenicity of mangoes. The total proteins, soluble proteins, peptides, amino acid nitrogen, the SDS-PAGE profiles of the protein extracts, and immunoreactivity of the sediment and supernatant were measured in two fermentation systems (juices and pieces fermentation). Throughout the fermentation, the pH decreased from about 4.6 to about 3.6, and the dissolved oxygen reduced about 50% on average. However, the protein degradation and sensitization reduction of mangoes were different between the two fermentation systems. In juices fermentation, there was a drop in proteins and peptides but an increase in amino acids, due to the conversion of proteins and peptides into amino acids both in the supernatant and sediment. The allergenicity decreased both in the solid and liquid phases of juices fermentation. In pieces fermentation, proteins and peptides were decreased in the solid phase but increased in the liquid phase. This was due to the fact that proteins and peptides were partly transported into the culture liquid, resulting in a decrease of allergenicity in fruit pieces and an increase in culture liquid. The principal component analysis results showed that the fermentation type had significant effects on the protein degradation and sensitization reduction, while mango variety had no significant effect. These results demonstrate that kombucha fermentation can reduce the allergenicity of mangoes, and it is more effective in juices fermentation than in pieces fermentation. The present study provides a theoretical basis for developing hypoallergenic mango products.

Protective effects and mechanism of Paecilomyces cicadae TJJ1213 intracellular polysaccharide against H2 O2 -induced PC12 cells damage.

Oxidative stress is a key process in the development of neurodegenerative diseases. More attention is needed to screen natural antioxidants and explore pharmacological mechanisms. Natural product polysaccharides with no toxic side effects have powerful antioxidant activity. Two purified intracellular polysaccharide fractions (IPS1 and IPS2) from Paecilomyces cicadae TJJ1213 was isolated. Then, a model of H2 O2 -induced oxidative stress in PC12 cells was established to investigate the neuroprotective role of IPS and elucidate the potential protection mechanism. Results showed that IPS1 and IPS2 reduced reactive oxygen species (ROS) production, inhibited the leakage of lactate dehydrogenase (LDH) and Ca2+ and attenuated the expression of apoptotic proteins. In addition, western blots displayed that IPS1 and IPS2 significantly inhibited mitophagy induced by H2 O2 in PC12 cells via PINK/Parkin pathway. Therefore, IPS1 and IPS2 deserved further investigation as protective agents against neurodegenerative diseases.

Solid-state fermentation alters the fate of red kidney bean protein during buccal and gastrointestinal digestion: Relationship with cotyledon cell wall integrity.

The relationship between legume cotyledon cell wall and macromolecular nutrient digestibility has attracted increased attention. In this study, the effect of solid-state fermentation by Rhizopus oligosporus RT-3 on the digestibility of red kidney bean protein and its relationship with cotyledon cell integrity were investigated. Buccal digestion and gastrointestinal digestion were performed to compare the fate of protein between unfermented (F0) and fermented samples. Results showed a remarkable disruption in cotyledon cell integrity at the late fermentation period, and it was accompanied by a possible migration/degradation of protein matrix. Buccal and gastrointestinal digestion barely affected cell wall integrity at F0 but notably disintegrated cell morphology at 29 h of fermentation (F29). As this fermentation time, gastrointestinal digestion resulted in higher contents of soluble proteins, peptides, and free amino acids by 1.4-, 1.8-, and 2.5-fold, respectively. Therefore, solid-state fermentation facilitated the structural breakdown of cotyledon cell walls, thereby further improving protein digestibility.

Characterization and Immunological Activity of Exopolysaccharide from Lacticaseibacillus paracasei GL1 Isolated from Tibetan Kefir Grains.

Two exopolysaccharide fractions (GL1-E1 and GL1-E2) of Lacticaseibacillus paracasei GL1 were isolated with the molecular weights of 3.9 × 105 Da and 8.2 × 105 Da, respectively. Both fractions possessed mannose, glucose, and galactose in molar ratios of 1.16:1.00:0.1, and 3.81:1.00:0.12, respectively. A structural arrangement of two fractions was proposed by methylation, one-dimensional and two-dimensional nuclear magnetic resonance experiments. The backbone of GL1-E1 consisted of →4)-α-D-Glcp(1→, →3,4)-α-D-Manp(1→, →3,6)-α-D-Manp(1→, →6)-α-D-Manp(1→, and →6)-α-D-Galp(1→ with α-D-Glcp at branching point. The backbone of GL1-E2 consisted of →4)-α-D-Glcp(1→, →3,4)-α-D-Manp(1→, →3,6)-α-D-Manp(1→, →6)-α-D-Manp(1→, →6)-α-D-Galp(1→, and →4)-ß-D-Manp(1→, and the side chain also consisted of α-D-Manp residue. In addition, the differential scanning calorimetry (DSC) analysis indicated that both GL1-E1 and GL1-E2 had good thermal stability. Furthermore, the two fractions could promote the viability of RAW264.7 cells and exert an immunomodulatory role by enhancing phagocytosis, increasing nitric oxide (NO) release and promoting the expression of cytokines.

Mechanochemical preparation of triptolide-loaded self-micelle solid dispersion with enhanced oral bioavailability and improved anti-tumor activity.

Triptolide (TP), a compound isolated from a Chinese medicinal herb, possesses potent anti-tumor, immunosuppressive, and anti-inflammatory properties, but was clinically limited due to its poor solubility, bioavailability, and toxicity. Considering the environment-friendly, low-cost mechanochemical techniques and potential dissolution enhancement ability of Na2GA, an amorphous solid dispersion (Na2GA&TP-BM) consisting of TP and Na2GA were well-prepared to address these issues. The performance of Na2GA&TP-BM was improved through ball milling, such as from crystalline state to an amorphous solid dispersion, suitable nano micelle size and surface potential, and increased solubility. This change had a significant improvement of pharmacokinetic behavior in mice and could be able to extend the blood circulation time of the antitumor drug. Moreover, in vitro and in vivo anti-tumor study showed that Na2GA&TP-BM displayed more potent cytotoxicity to tumor cells. The work illustrated an environment-friendly and safe preparation of the TP formulation, which was promising to enhance the oral bioavailability and antitumor ability of TP, might be considered for efficient anticancer therapy.

In situ exopolysaccharides produced by Lactobacillus helveticus MB2-1 and its effect on gel properties of Sayram ketteki yoghurt.

In order to study the mechanism of high viscosity of Sayram ketteki yoghurt, the growth, acidification properties, in situ exopolysaccharides (EPS) production of Lactobacillus helveticus MB2-1 in milk medium were investigated. The microstructure of the yoghurt was analyzed. The characteristics of in situ EPS produced by this strain in yoghurt were studied by high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) analysis. The amount of in situ EPS produced could be up to 689.47 mg/L. The micrographs of Sayram ketteki yoghurt demonstrated that the in situ EPS secreted by ropy L. helveticus MB2-1 were closely connected with proteins, effectively filling the three-dimensional network structure of casein clusters, thereby resulting in high viscosity of yoghurt. Besides, the molecular weight of in situ EPS was 9.34 × 104 Da, and the in situ EPS was determined to be a new heteropolysaccharide, containing fucose, which made it unique. Moreover, the set yoghurts added with in situ EPS were demonstrated fine effects on the texture improvement. These results illustrated that L. helveticus MB2-1 could be set as a good starter and the in situ EPS could be considered as a probiotic stabilizer substitute for fermented dairy products.

The Conformational Structural Change of Soy Glycinin via Lactic Acid Bacteria Fermentation Reduced Immunoglobulin E Reactivity.

This study investigated the fermentation of isolated soy glycinin by using the Lactiplantibacillus plantarum B1-6 strain, its reduction effect on immunoglobulin E (IgE) reactivity, the relationship with protein aggregation/gelation state and conformational changes. Fermentation was performed under different glycinin concentrations (0.1%, 0.5%, 1% and 2%, w/v) and varied fermentation terminal pH levels (FT-pH) (pH 6.0, 4.5, 4.0 and 3.5). L. plantarum B1-6 showed potency in reducing immunoreactivity to 0.10-69.85%, as determined by a sandwich enzyme-linked immunosorbent assay. At a FT-pH of 6.0 and 4.5, extremely low IgE reactivity (0.1-22.32%) was observed. Fermentation resulted in a great increase (2.31-6.8-fold) in particle size and a loss of intensity in A3 and basic subunits. The conformation of glycinin was altered, as demonstrated by improved surface hydrophobicity (1.33-7.39-fold), decreased intrinsic fluorescence intensity and the α-helix structure. Among the four selected concentrations, glycinin at 1% (w/v, G-1) evolved the greatest particles during fermentation and demonstrated the lowest immunoreactivity. Principal component analysis confirmed that particle size, intrinsic fluorescence intensity, α-helix and ionic bond were closely related to immunoreactivity reduction.

Structural Characterization and Antioxidant Activity of Exopolysaccharide from Soybean Whey Fermented by Lacticaseibacillus plantarum 70810.

Soybean whey is a high-yield but low-utilization agricultural by-product in China. In this study, soybean whey was used as a substrate of fermentation by Lacticaseibacillus plantarum 70810 strains. An exopolysaccharide (LPEPS-1) was isolated from soybean whey fermentation by L. plantarum 70810 and purified by ion-exchange chromatography. Its preliminary structural characteristics and antioxidant activity were investigated. Results show that LPEPS-1 was composed of mannose, glucose, and galactose with molar ratios of 1.49:1.67:1.00. The chemical structure of LPEPS-1 consisted of →4)-α-D-Glcp-(1→, →3)-α-D-Galp-(1→ and →2)-α-D-Manp-(1→. Scanning electron microscopy (SEM) revealed that LPEPS-1 had a relatively rough surface. In addition, LPPES-1 exhibited strong scavenging activity against DPPH and superoxide radicals and chelating ability on ferrous ion. This study demonstrated that soybean whey was a feasible fermentation substrate for the production of polysaccharide from L. plantarum 70810 and that the polysaccharide could be used as a promising ingredient for health-beneficial functional foods.

The correlation of serum Vaspin, S100A12 and PCT levels with the severity of ulcerative colitis and its clinical significance.

OBJECTIVE: This study aimed to investigate the correlation between Vaspin, S100A12 and PCT levels and ulcerative colitis (UC). METHODS: This study included 104 patients with UC from November 2018 to June 2020 as the experimental group, including 37 cases in remission and 67 cases in an active phase; patients in an active phase were classified into 17 cases of mild, 37 cases of moderate and 13 cases of severe according to Modified Mayo Endoscopic Score (MMES). There were 104 patients as healthy controls during the same period who were enrolled as the control group. Serum levels of Vaspin, S100A12, PCT, inflammatory factors and immunoglobulins were compared between two groups and the correlation between serum levels of each index and the severity of UC was analyzed. RESULTS: Compared with the control group, serum Vaspin, S100A12, and PCT levels were higher in the experimental group, and serum Vaspin, S100A12, and PCT levels were higher in the active phase than in the remission phase (P < 0.05). Serum Vaspin, S100A12, PCT, IL-6, IL-17, TNF-α levels: Severe patients > moderate patients > mild patients; Serum IgA, IgG levels: Severe < moderate < mild (P < 0.05). As shown by Spearman analysis, serum Vaspin, S100A12, PCT, IL-6, IL-17, and TNF-α levels were positively correlated with (r=0.317, P=0.021) while serum IgA and IgM were negatively correlated with the severity of UC disease (r=-0.418, P=0.007). CONCLUSION: Serum Vaspin, S100A12, PCT and inflammatory factor levels were positively correlated with the severity of UC disease, and they showed significance in the assessment of the severity and prognosis of UC.

Simulated digestion and fecal fermentation behaviors of exopolysaccharides from Paecilomyces cicadae TJJ1213 and its effects on human gut microbiota.

This study aimed to explore the in vitro simulated digestion and fecal fermentation behaviors of two purified exopolysaccharide fractions (EPS1 and EPS2) from Paecilomyces cicadae TJJ1213 and its effects on human gut microbiota composition. Results showed that EPS1 and EPS2 could not be digested by saliva-gastrointestinal. After fecal fermentation, however, the molecular weight of EPS1 and EPS2 significantly decreased, and the molar ratios of the monosaccharide composition remarkably changed, indicating that EPS1 and EPS2 could be degraded and consumed by human gut microbiota. Notably, EPS1 and EPS2 could significantly modulate the composition, via increasing the relative abundances of Bacteroides and Phascolarctobacterium and decreasing the pathogenic bacteria Escherichia-Shigella, Klebsiella and Fusobacterium. In addition, EPS1 and EPS2 also could promote the production of short-chain fatty acids during fermentation for 24 h. These results suggested that EPS from Paecilomyces cicadae TJJ1213 can be used as a functional food to improve health and prevent diseases by promoting gut health.

Structural characterization and immunomodulatory activity of intracellular polysaccharide from the mycelium of Paecilomyces cicadae TJJ1213.

Two intracellular polysaccharide fractions (IPS1 and IPS2) were obtained from the mycelium of Paecilomyces cicadae TJJ1213, and the structures were conducted. Results showed that they were homogenous with the average molecular weight of 2.40 × 106 Da and 6.79 × 105 Da. Two fractions were composed of mannose, glucose and galactose with molar ratios of 1.35: 6.93: 1.0 and 2.04: 1.0: 1.87, respectively. The backbone of IPS1 was â†’ 4)-α-D-Glcp (1 â†’ and â†’ 3,4)-α-D-Manp (1 â†’ residues with a side chain consisted of T-α-D-Galp. IPS2 was consisted of â†’ 4)-α-D-Glcp-(1→, →3,4)-α-D-Manp-(1 â†’ and â†’ 2,6)-α-D-Manp-(1 â†’ residues and the branches were also consisted of T-α-D-Galp. In addition, the scanning electron microscope and atomic force microscope images presented different features of IPS1 and IPS2, respectively. Furthermore, two fractions exhibited better immunomodulatory effects. They could markedly promote the proliferation of RAW264.7 cells and enhance phagocytosis, nitric oxide release and cytokines production. These results indicated that IPS1 and IPS2 had potential to enhance immune responses.

Mechanochemical preparation of chrysomycin A self-micelle solid dispersion with improved solubility and enhanced oral bioavailability.

BACKGROUND: Chrysomycin A (CA) has been reported as numerous excellent biological activities, such as antineoplastic and antibacterial. Though, poor solubility of CA limited its application in medical field. Due to good amphiphilicity and potential anticancer effect of disodium glycyrrhizin (Na2GA) as an excipient, an amorphous solid dispersion (Na2GA/CA-BM) consisting of CA and Na2GA was prepared in the present study by mechanochemical technology (roll mill ML-007, zirconium balls, 30 rpm, 2.5 h) to improve the solubility and oral bioavailability of CA. Then, Na2GA/CA-BM was self-assembled to micelles in water. The interaction of CA and Na2GA in solid state were investigated by X-ray diffraction studies, polarized light microscopy, and scanning electron microscope. Meanwhile, the properties of the sample solution were analyzed by dynamic light scattering and transmission electron. Furthermore, the oral bioavailability and antitumor ability of Na2GA/CA-BM in vivo were tested, providing a theoretical basis for future application of CA on cancer therapy. RESULTS: CA encapsulated by Na2GA was self-assembled to nano-micelles in water. The average diameter of nano-micelle was 131.6 nm, and zeta potential was - 11.7 mV. Three physicochemical detections showed that CA was transformed from crystal into amorphous form after treated with ball milling and the solubility increased by 50 times. Na2GA/CA-BM showed a significant increase of the bioavailability about two time that of free CA. Compared with free CA, the in-vivo antitumor studies also exhibited that Na2GA/CA-BM had an excellent inhibition of tumor growth. CONCLUSIONS: Na2GA/CA-BM nanoparticles (131.6 nm, - 11.7 mV) prepared by simple and low-cost mechanochemical technology can improve oral bioavailability and antitumor efficacy of CA in vivo, suggesting a potential formulation for efficient anticancer treatment.

Isolation, structural characterization and neuroprotective activity of exopolysaccharide from Paecilomyces cicada TJJ1213.

Two exopolysaccharide fractions (EPS1 and EPS2) were obtained from Paecilomyces cicadae TJJ 1213, and their structures were elucidated. The EPS1 and EPS2 were mainly composed of mannose and galactose with molar ratios of 3.2: 1.0 and 2.7: 1.0, respectively. They possessed average molecular weights of 1.69 × 106 and 8.06 × 105 Da, respectively. Structural characterization indicated that the backbone of EPS1 was consisted of →4)-α-D-Manp (1→, →3,4)-α-D-Manp (1 → and →2,6)-α-D-Manp (1→, →6)-α-D-Galp (1→, →6)-ß-D-Galp (1→, and side chain was consisted of α-D-Manp residue. The backbone of EPS2 was composed of →6)-ß-D-Galp-(1→, →4)-α-D-Manp-(1→, →2,6)-α-D-Manp-(1 → and →6)-α-D-Galp-(1→, and the branching point was also consisted of α-D-Manp residue. In addition, EPS1 and EPS2 had potential in protective effects of PC12 cells against hydrogen peroxide induced oxidative stress by inhibiting the production of ROS, reducing LDH leakage and alleviating mitochondrial damage. These results indicated that EPS1 and EPS2 might serve as therapeutic agents for neuronal disorders.

Biosynthesis of exopolysaccharide and structural characterization by Lacticaseibacillus paracasei ZY-1 isolated from Tibetan kefir.

Exopolysaccharide (EPS) was produced by Lacticaseibacillus paracasei ZY-1 isolated from Tibetan kefir grains, and the preliminary structure of two EPS fractions (EPS1 and EPS2) was investigated. NMR analysis revealed that the backbone of higher producing EPS1 was consisted of →6)-α-D-Manp-(1→, →2,6)-α-D-Glcp-(1→, α-D-Manp-(1→, →2)-α-D-Glcp-(1→, →3)-α-D-Manp-(1→, →6)-α-D-Glcp-(1→. Furthermore, an eps gene cluster that encodes the glycosyltransferase and relevant proteins for EPS biosynthesis was identified on the basis of bioinformation analysis of the complete genome. RT-qPCR results indicated that wzd (ZY-1_2260) and wze (ZY-1_2259) might be essential genes involved in EPS production. Meanwhile, the synthetic mechanism of EPS1 in L. paracasei ZY-1 was further proposed. Besides, the crude and purified EPS showed certain scavenging activities against DPPH, hydroxyl and ABTS radicals. Results provided a better understanding of EPS biosynthesis in L. paracasei ZY-1 at the gene level.

Anticancer potential of an exopolysaccharide from Lactobacillus helveticus MB2-1 on human colon cancer HT-29 cells via apoptosis induction.

This study aimed at investigating the anticancer activity of an exopolysaccharide (EPS) isolated from Lactobacillus helveticus MB2-1. The crude EPS from L. helveticus MB2-1 (LHEPS) was fractionated into three fractions, namely LHEPS-1, LHEPS-2 and LHEPS-3. LHEPS-1 exhibited the most effective anti-proliferative activity, which was associated with a stronger inhibition rate and increased lactate dehydrogenase leakage of human colon cancer HT-29 cells. Flow cytometry analysis and colorimetric assay revealed that LHEPS-1 induced cell cycle arrest by preventing G1 to S transition and increased the apoptosis rate. Furthermore, LHEPS-1 enhanced the production of intracellular reactive oxygen species (ROS) and the activity of caspases-8/9/3, increased the levels of pro-apoptotic Bax and mitochondrial cytochrome c, while decreased the anti-apoptotic Bcl-2 level, indicating that LHEPS-1 might induce the apoptosis of HT-29 cells through a ROS-dependent pathway and a mitochondria-dependent pathway. These findings suggest that LHEPS-1 may be developed as an effective food and/or drug for the prevention and therapeutics of cancer, especially human colon cancer.

Assessment of the effect of lactic acid fermentation on the gastroduodenal digestibility and immunoglobulin E binding capacity of soy proteins via an in vitro dynamic gastrointestinal digestion model.

Fermentation by lactic acid bacteria is helpful in reducing soy protein immunoreactivity. However, how lactic acid fermentation influences the gastroduodenal digestibility and immunoglobulin E (IgE) binding capacity of soy proteins remains unclear. In this study, the protein digestion of a fermented soybean protein isolate (FSPI) was investigated and compared with that of a soybean protein isolate (SPI). The effect on their respective IgE binding capacities at the gastric and duodenal phases was also explored by using a novel in vitro dynamic gastrointestinal digestion model (Bionic Rat Model II+). Medium pH was measured, microstructural analysis was performed, peptide distribution and free amino acid content were determined, and SDS-PAGE analysis was performed to assess the differences between SPI and FSPI. The results showed that FSPI had lower pH (3.76), larger protein aggregates (>60 µm), and higher low-molecular-weight peptides than SPI. During the first 30 min of gastric and duodenal digestion, the extent of hydrolysis of FSPI was higher than that of SPI, and the gastric transition time of the former was longer than that of the latter. Conversely, differences tended to be narrower in the next 30-180 min of gastric and duodenal digestion. As a result, the IgE binding capacity of FSPI was significantly lower than that of SPI at 30 min of gastric and duodenal digestion. Therefore, fermentation by lactic acid bacteria affected the digestibility rate of soy proteins, especially at the initial phases of gastric and duodenal digestion, thereby reducing the exposure of intact epitopes in the duodenum. This study helped to elucidate how lactic acid fermentation affected the digestive behavior of soy proteins and its implication in IgE immunoreactivity reduction.

Isolation, purification, characterization and immunostimulatory activity of an exopolysaccharide produced by Lactobacillus pentosus LZ-R-17 isolated from Tibetan kefir.

In this study, three strains of lactic acid bacteria isolated from Tibetan kefir grains, including two strains of Lactobacillus pentosus LZ-R-17 and L. helveticus LZ-R-5, and one strain of Lactococcus lactis subsp. lactis LZ-R-12. The ability of three strains to produce exopolysaccharide (EPS) was tested, and L. pentosus LZ-R-17 was found to have the highest EPS yield. One EPS (R-17-EPS) was isolated from the fermented milk by L. pentosus LZ-R-17 and purified by DEAE-52 anion exchange chromatography. Furthermore, R-17-EPS preliminary structure and macrophage immunomodulatory activity in vitro were investigated. On the basis of the analytical results of ultraviolet-visible spectrum, Fourier transform-infrared spectrum, monosaccharide composition analysis and one-dimensional and two-dimensional nuclear magnetic resonance (NMR) spectra, R-17-EPS was found to have an average molecular weight of 1.20 × 106 Da and was composed of galactose and glucose residues with a molar ratio of 1.00:3.15. NMR analysis revealed that the R-17-EPS was a linear hetero-galactoglucan containing repeating units of →2)-α-D-Galp-(1 â†’ 4)-ß-D-Glcp-(1 â†’ 4)-ß-D-Glcp-(1 â†’ 4)-ß-D-Glcp-(1→. In addition, R-17-EPS could effectively enhanced the proliferation, phagocytosis, nitric oxide and cytokines production of RAW264.7 cells, suggesting that R-17-EPS had potent immunostimulatory activity and could be explored as immunomodulator in functional food and/or medicine fields.

Influences of drying methods on the structural, physicochemical and antioxidant properties of exopolysaccharide from Lactobacillus helveticus MB2-1.

In this study, in order to evaluate influences of different drying methods on the structural characteristics, physicochemical properties and antioxidant activities of exopolysaccharides (EPS) from Lactobacillus helveticus MB2-1, three drying methods, including spray-drying (SD), freeze-drying (FD) and spray freeze-drying (SFD), were applied to dry EPS. Results showed that different drying procedures had no significant influence on the primary structure and constituent monosaccharides of EPSs. However, the surface morphology of the three dried EPSs varied greatly in size and shape due to different drying processes. Among three dried EPSs, the particle size distribution of spray freeze-dried EPS (SF-EPS) was relatively narrower and uniform. Additionally, SF-EPS behaved better apparent viscosity and emulsifying property than spray-dried EPS (S-EPS) and freeze-dried EPS (F-EPS). SF-EPS exhibited stronger antioxidant activities when compared with S-EPS and F-EPS, according to the results of scavenging activities on different radicals and chelating activity on ferrous ion. Overall, SFD was the appropriate method for industrial production of EPS from Lactobacillus helveticus MB2-1 with better physicochemical properties and antioxidant activities.

Structural characterization and immunomodulatory activity of an exopolysaccharide produced by Lactobacillus helveticus LZ-R-5.

Exopolysaccharide (R-5-EPS) was isolated from the fermented milk of Lactobacillus helveticus LZ-R-5 and purified by DEAE-52 cellulose anion-exchange column, and characterization of the structure was conducted. Results showed that R-5-EPS was a heteropolysaccharide containing linear repeating units of →6)-ß-D-Galp-(1→3)-ß-D-Glcp-(1→3)-ß-D-Glcp-(1→3)-ß-D-Glcp-(1→3)-ß-D-Glcp-(1→ with an average Mw of 5.41 × 105 Da. Furthermore, at a cellular level, R-5-EPS showed immunostimulatory activity due to its strong effect on increasing proliferation of RAW264.7 macrophages and enhancing phagocytosis, acid phosphatase activity, nitric oxide production and cytokines production in macrophages. These results suggest that R-5-EPS have a potent immunostimulatory activity and may be explored as a potential immunomodulatory agent.

In vitro digestion and fermentation of released exopolysaccharides (r-EPS) from Lactobacillus delbrueckii ssp. bulgaricus SRFM-1.

The aim of this study was to investigate the in vitro digestion and fermentation prebiotic properties of three released-exopolysaccharide fractions (r-EPS1, r-EPS2 and r-EPS3) from Lactobacillus delbrueckii ssp. bulgaricus SRFM-1. There were no free oligosaccharides and/or monosaccharides for r-EPS1 before and after simulated buccal, gastric and small intestinal (GSI) digestion in vitro. In contrast, r-EPS2 (13.4 %) and r-EPS3 (10.6 %) generated a few monosaccharides after digestion. Additionally, r-EPS1 and r-EPS2 seemed to present a strong bifidogenic effect comparing to inulin, as they exhibited high values of selectivity index (13.17 and 12.84, respectively). Furthermore, the fermentation with r-EPS1 produced the highest contents of acetic acid and lactic acid (56.3 mM and 44.29 mM, respectively), which resulted in the highest amounts of total short chain fatty acid (145.51 mM) followed by r-EPS2 (135.57 mM) and inulin (99.28 mM). These results indicated that r-EPS from L. delbrueckii ssp. bulgaricus SRFM-1 could be a good potential candidate for new functional food prebiotic.