Microbial Diversity and Volatile Flavor Changes during Gayangju Fermentation, a Traditional Korean House Rice Wine.

Physicochemical changes in fermented alcoholic beverages are significantly related to microbial community development during fermentation. Due to its unusually long fermentation, Gayangju, a traditional Korean house rice wine fermented with nuruk as the traditional starter, gives rise to a strong yeast community and, therefore, a high ethanol concentration and different flavors. However, no detailed analysis has been examined. Changes in microbial community structure during Gayangju fermentation were examined using both culture-dependent and culture-independent methods. During fermentation, Saccharomyces cerevisiae and Saccharomycopsis fibuligera were dominant during all stages of the fermentation. In contrast, Candida parapsilosis, Hanseniaspora guilliermondii, Pichia anomala, Malassezia cuniculi and P. fermentans were identified as minor. P. anomala appeared after the second brewing and then remained constant. Among the 19 compounds identified in this study as order-active compounds, 2-methyl-1-butanol (isoamyl alcohol) was the major compound that increased during the long fermentation stage. Most of the odor-active compounds such as 2,3-butanediol, 3-methyl-1-butanol, ethyl tetradecanoate, ethyl decanoate, ethyl dodecanoate, butanoic acid, 3-methylbutanoic acid (isovaleric acid), 2-methylbutanoic acid, 2-methyl-1-propanol, ethyl acetate, ethyl caprylate, 2-phenylethanol, and 3-methylbutyl acetate increased as the fermentation progressed during 68 days of fermentation, which showed significant differences in the concentrations of odor-active compounds of commercially fermented makgeolli.

Evaluation of Probiotic Properties of Pediococcus acidilactici M76 Producing Functional Exopolysaccharides and Its Lactic Acid Fermentation of Black Raspberry Extract.

This study aimed to determine the probiotic potential of Pediococcus acidilactici M76 (PA-M76) for lactic acid fermentation of black raspberry extract (BRE). PA-M76 showed outstanding probiotic properties with high tolerance in acidic GIT environments, broad antimicrobial activity, and high adhesion capability in the intestinal tract of Caenorhabditis elegans. PA-M76 treatment resulted in significant increases of pro-inflammatory cytokine mRNA expression in macrophages, indicating that PA-M76 elicits an effective immune response. When PA-M76 was used for lactic acid fermentation of BRE, an EPS yield of 1.62 g/L was obtained under optimal conditions. Lactic acid fermentation of BRE by PA-M76 did not significantly affect the total anthocyanin and flavonoid content, except for a significant increase in total polyphenol content compared to non-fermented BRE (NfBRE). However, fBRE exhibited increased DPPH radical scavenging activity, linoleic acid peroxidation inhibition rate, and ABTS scavenging activity of fBRE compared to NfBRE. Among the 28 compounds identified in the GC-MS analysis, esters were present as the major groups. The total concentration of volatile compounds was higher in fBRE than that in NfBRE. However, the undesirable flavor of terpenes decreased. PA-M76 might be useful for preparing functionally enhanced fermented beverages with a higher antioxidant activity of EPS and enhanced flavors.

Rose Petal Extract (Rosa gallica) Exerts Skin Whitening and Anti-Skin Wrinkle Effects.

We sought to investigate the effect of extracts from Rosa gallica petals (RPE) on skin whitening and anti-wrinkle activity. Tyrosinase activity was attenuated by RPE treatment, concomitant with the reduction of melanin accumulation in human B16F10 melanoma. Treatment of the facial skin of volunteers in a clinical trial with an RPE-containing formulation enhanced skin brightness (L* value) significantly. The underlying mechanism responsible was determined to be associated with mitogen-activated protein kinase (MAPK) activation. In addition, RPE exhibited anti-wrinkle formation activity of human dermal fibroblasts by suppressing matrix metalloproteinase (MMP)-1 level. In vivo study, RPE also inhibited solar ultraviolet-stimulated MMP-1 level by c-Jun regulation. Overall, our findings indicate that RPE evokes skin whitening and anti-wrinkle formation activity by regulating intracellular signaling, supporting its utility as an ingredient for skin whitening and anti-wrinkle cosmetic products.

Acute Oral Toxicity and Genotoxicity of Polysaccharide Fraction from Young Barley Leaves (Hordeum vulgare L.).

Polysaccharides isolated from various plants are considered precious bioactive materials owing to their potent biological activities. Previously, we prepared a polysaccharide fraction (BLE0) isolated from young barley leaves (Hordeum vulgare L.), demonstrating its anti-osteoporotic and immunostimulatory activities. However, data regarding BLE0 toxicity is lacking. To establish its safety, in vitro genotoxicity (chromosomal aberration and bacterial reverse mutation assays) and acute oral toxicity assays were conducted. In the in vitro genotoxicity assays, bacterial reverse mutation and chromosomal aberration assays showed that BLE0 possessed no mutagenicity or clastogenicity. Furthermore, the median lethal dose (LD50) of BLE0 was higher than 5000 mg/kg in female and male Sprague-Dawley (SD) rats and no adverse effects were observed in terms of mortality and abnormal changes in clinical signs (body weight and necropsy). Based on these results, BLE0 was found to be safe with regards to genotoxicity under our test conditions, demonstrating no acute oral toxicity up to 5000 mg/kg in SD rats.

Polysaccharides isolated from lotus leaves (LLEP) exert anti-osteoporotic effects by inhibiting osteoclastogenesis.

Nelumbo nucifera, more commonly known as the Indian lotus, is an important plant that has been incorporated into traditional herbal remedies along the years. Even today, lotus leaves are considered reservoirs for bioactive compounds that can be used as nutritional supplements to treat various human diseases. However, despite the wide ranging biological activities of lotus polysaccharides, limited information is available regarding the anti-osteoporotic effects of these substances. The aim of this study was to investigate the beneficial effects of pectinase-assisted extractable polysaccharides from lotus leaves (LLEP) on estrogen deficiency-induced bone loss and osteoclast differentiation in bone marrow-derived macrophages. We found that LLEP markedly inhibited receptor activator of the nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation in a dose-dependent manner. It also revoked RANKL-induced activation of osteoclastogenic signals such as the expression of key transcription factors (i.e., c-Fos and nuclear factor of activated T cells cytoplasmic 1), resulting in a decrement in osteoclast-specific marker gene expressions. Microcomputed tomography and morphometric analysis revealed that a four-week oral administration of LLEP notably decreased trabecular bone loss. Taken together, our results suggest that LLEP can mitigate estrogen deficiency-induced bone loss by suppressing osteoclastogenesis, which makes it an excellent candidate for combating osteoporosis.

Effect of enzyme-assisted extraction on the physicochemical properties and bioactive potential of lotus leaf polysaccharides.

Lotus leaf polysaccharides were extracted by enzyme-assisted extraction using α-amylase (LLEP-A), cellulose (LLEP-C), pectinase (LLEP-P) or protease (LLEP-PR). Their physicochemical properties and immunostimulatory activities were compared with those of hot-water extracted polysaccharides (LLWP). HPAEC-PDA and HPSEC-RI profiles indicated that variations in their molecular weight patterns and chemical compositions. Moreover, their effects on proliferation, phagocytic activity, and cytokine production in macrophages could be ordered as LLEP-P > LLEP-C > LLEP-A > LLWP > LLEP-PR, suggesting that LLEP-P by pectinase-assisted extraction was the most potent enhancer of macrophage activation. LLEP-P was further purified by gel filtration, and the main fraction (LLEP-P-І) was obtained to elucidate the structural and functional properties. LLEP-P-І (14.63 × 103 g/mol) mainly consisted of rhamnose, arabinose, galactose, and galacturonic acid at molar percentages of 15.5:15.8:20.1:32.8. FT-IR spectra indicated the predominant acidic and esterified form, suggesting the pectic-like structure. Above all, LLEP-P-І exerted greater stimulation effects on NO and cytokines production and the phagocytic activity in macrophages. Transcriptome analysis also demonstrated that LLEP-P and LLEP-P-І could upregulate macrophage immune response genes, including cytokines, chemokines, and interferon via TLR and JAK-STAT signaling. Thus, these results suggest that pectinase application is most suitable to obtain immunostimulatory polysaccharides from lotus leaves.

Immunostimulatory effects of polysaccharides isolated from young barley leaves (Hordeum vulgare L.) with dual activation of Th1 and Th2 in splenic T cells and cyclophosphamide-induced immunosuppressed mice.

Botanical polysaccharides have been widely known to possess immunological activity. The objective of this study was to investigate the molecular mechanisms underlying the immunostimulatory properties of polysaccharides isolated from barley leaf (Hordeum vulgare L.) (BLE0) in splenocytes and cyclophosphamide (CYP)-induced immunosuppressed mice. BLE0 showed cell proliferative activity and markedly increased the secretion of both Th1-cytokines (IFN-γ and IL-2) and Th2-cytokines (IL-4 and IL-10) in CD3/CD28-activated splenocytes. Molecular data revealed that BLE0 up-regulated the expression of T-bet with enhanced phosphorylation of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) 1 signaling pathway. BLE0 also increase the phosphorylation of GATA3 via toll-like receptor (TLR) 2-mediated signaling pathway with nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and activator protein 1 (AP-1) activation. Oral administration of BLE0 effectively improved CYP-induced decrease of body weight, splenocyte proliferation, and natural killer (NK) cell cytotoxic activity and significantly increased Th1 and Th2 cytokines, T-bet, and GATA3 mRNA expression. Dietary intake of BLE0 improves the immunological manifestations by stimulating both Th1 and Th2 responses via JAK/STAT1/T-bet and TLR2/GATA3, respectively.

Extraction conditions for Rosa gallica petal extracts with anti-skin aging activities.

The anti-skin inflammatory activities of rose petal extracts have been described in our previous study. Because skin inflammation is closely linked to skin aging, our study investigated the effects of Rosa gallica petals on skin aging-related activities such as skin whitening and anti-wrinkle properties. Each sample was prepared via extraction using different ethanol ratios with the objective of evaluationg optimal extraction conditions for industrial application. Aqueous 50% (v/v) EtOH extract of R. gallica petal significantly suppressed tyrosinase activity, melanin production, and solar UV-induced matrix metalloproteinase-1, a hall mark of wrinkle formation. In addition, the aqueous 50% (v/v) EtOH extract showed the highest antioxidative effect and had highest flavonoid contents, consistent with the reported anti-aging effects. Overall, our findings suggest that R. gallica petals extracts exhibit anti-aging effects. Furthermore, 50% EtOH extraction, in particular, was optimal for the highest anti-aging, and anti-oxidative effects as well as to obtain the highest flavonoid content.

Isolation, purification, and characterization of novel polysaccharides from lotus (Nelumbo nucifera) leaves and their immunostimulatory effects.

In this study, a crude water-soluble polysaccharide (LLWP-C) was extracted from lotus leaves and further purified by size exclusion chromatography, to obtain the two main polysaccharides, LLWP-1 and LLWP-3. Physical and chemical analyses showed that they were homogeneous polysaccharides in ß-type glycosidic linkage. LLWP-1 was devoid of helical conformation, had a molecular weight of 85.1 kDa and was mainly composed of Rha, Ara, Gal, Glu, and GalA in a molar ratio of 7.0:24.8:28.0:6.0:26.4. LLWP-3 showed a helical conformation, had a molecular weight of 12.5 kDa and consisted mainly of Rha, Ara, Gal, Glu, Man, and GalA in a molar ratio of 6.6:9.8:15.0:8.9:6.1:47.2. It was demonstrated that LLWP-C and both purified LLWP-1 and LLWP-3 could effectively enhance the proliferation, phagocytosis, nitric oxide (NO), and cytokine secretions by activating corresponding mRNA expression in macrophages, via MAPK and NF-κB pathways. LLWP-3 displayed the greatest immunostimulatory potential, followed by LLWP-1 and LLWP-C. These findings suggest that polysaccharides extracted from lotus leaf exert immunostimulatory activity that could be further investigated to develop functional foods and natural immunopotentiating therapeutic agents.

Discrimination of Structural and Immunological Features of Polysaccharides from Persimmon Leaves at Different Maturity Stages.

In this study, we investigated changes in the structural and immunological features of polysaccharides (S1-PLE0, S2-PLE0, and S3-PLE0) extracted from persimmon leaves at three different growth stages. Physicochemical analyses revealed that their chemical compositions, molecular weight distributions, and linkage types differed. High-performance size-exclusion chromatograms showed that the molecular weights of the polysaccharides increased during successive growth stages. In addition, seasonal variation of persimmon leaves affected the sugar compositions and glycosidic linkages in the polysaccharides. S2-PLE0 was composed of comparatively more galactose, arabinose, rhamnose, xylose, and galacturonic acid, showing the presence of ß-glucopyranoside linkages. Significant differences also occurred in their immunostimulatory effects on RAW264.7 macrophages, with respect to which their activities could be ordered as S2-PLE0 > S3-PLE0 > S1-PLE0. Evidently, S2-PLE0 showed the greatest immunostimulatory activity by enhancing the phagocytic capacity and promoting nitric oxide (NO) and cytokines secretion through the upregulation of their gene expression in macrophages. These results suggest that differences in the structural features of polysaccharides according to the different maturity of persimmon leaves might impact their immunostimulatory properties. The results also provide a basis for optimizing persimmon leaf cultivation strategies for food and medical uses of the polysaccharides.

Protective effects of a polysaccharide BLE0 isolated from barley leaf on bone loss in ovariectomized mice.

Potent anti-osteoporotic drugs have been developed over the past decades; however, the substantial need for treatments that can effectively and safely manage osteoporosis remains unmet. Barley leaf-derived products are one of best functional foods that can be used as nutritional supplements and detoxifiers in humans and are beneficial in improving bone disease. However, little information is available regarding the anti-osteoporotic effects of polysaccharides as the main component of barley leaf. This study aimed to clarify the beneficial effects of barley leaf (BLE0) polysaccharides on bone loss in ovariectomized mice and osteoclast differentiation in bone marrow-derived macrophages. BLE0 remarkably inhibited receptor activator of the nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation in a dose-dependent manner. It also blocked RANKL-induced activation of osteoclastogenic signals including ERK and p38 and the expression of nuclear factor of activated T cells cytoplasmic 1, as a master regulator of osteoclast differentiation, leading to decreased expression of osteoclast-specific marker genes such as Atp6v0d2, DC-STAMP and cathepsin K. Micro-computed tomography revealed that a seven-week oral administration of BLE0 dramatically improved ovariectomy-induced trabecular bone loss. Anti-osteoporotic effects were confirmed using morphometric analysis. Taken together, BLE0 is a bioactive polysaccharide; it mitigates estrogen deficiency-induced bone loss by directly inhibiting osteoclast differentiation.

The Effect of Pectinase-Assisted Extraction on the Physicochemical and Biological Properties of Polysaccharides from Aster scaber.

The edible and medicinal perennial herb Aster scaber is known to have anticancer, antioxidant, and immunomodulatory properties. However, the biological effects of its polysaccharides are not well understood. Here, we aimed to extract novel polysaccharides with enhanced biological properties from Aster scaber using enzyme-assisted methods. Amylase, cellulase, and pectinase were used to extract enzyme-assisted polysaccharide (ASEP)-A, ASEP-C, and ASEP-P, respectively. The yields, physicochemical properties, and immunostimulatory activities of the polysaccharides were investigated and compared with those of hot water extracted polysaccharide (ASWP). The highest yield (3.8%) was achieved for ASEP-P extracted using pectinase digestion. Fourier-transform infrared spectroscopy (FT-IR) and chemical composition analysis revealed that ASWP and three ASEPs were typical acidic heteropolysaccharides, mainly comprising rhamnose, arabinose, galactose, glucose, and galacturonic acid. Immunostimulatory activity assays on RAW264.7 macrophages showed ASEP-P to have the greatest immunostimulatory potential in terms of nitric oxide (NO) and cytokine productions and phagocytic activity. ASEP-P administration improved immune-enhancing effects in normal mice by improving the spleen index and splenic lymphocyte proliferation, and in immunosuppressed mice by modulating lymphocyte proliferation, natural killer (NK) cell activity, and leukocyte counts. The ASEP-P derived from pectinase hydrolysate of Aster scaber demonstrated efficacious immunostimulatory properties and has potential applications as an immune stimulator.

Inhibitory Effect of Opuntia humifusa Fruit Water Extract on Solar Ultraviolet-Induced MMP-1 Expression.

Opuntia humifusa is a type of cactus whose fruits have been used in folk medicine for the treatment of several diseases. In the present study, we aimed to determine whether O. humifusa fruit water extract (OHE) has inhibitory effects against solar ultraviolet (sUV)-induced matrix metalloproteinase-1 (MMP-1) expression. In ex vivo human skin, we found that OHE suppressed sUV radiation-induced MMP-1 expression. The inhibitory effect of OHE was confirmed in human dermal fibroblasts. OHE treatment reduced sUV-induced MMP-1 expression by suppressing reactive oxygen species (ROS) generation and phosphorylation of c-Jun, a component of transcription factor activator protein 1 (AP-1). On the other hand, OHE recovered the tissue inhibitor of matrix metalloproteinase 1 (TIMP-1) and type 1 collagen production attenuated by sUV. As upstream signaling pathways for AP-1, MKK4-JNK, MEK-ERK, and MKK3/6-p38 phosphorylation were downregulated by OHE treatment. In addition, OHE exhibited DPPH radical scavenging activity. These findings demonstrate that OHE has a preventive effect against sUV-induced skin damage via suppression of pathways triggered by ROS.

Anti-Osteoporotic Effects of Polysaccharides Isolated from Persimmon Leaves via Osteoclastogenesis Inhibition.

Persimmon (Diospyros kaki L.f.) leaves have traditionally been used as a phytomedicine, in health beverages to treat cardiovascular and respiratory disease and to promote maternal health in East Asia. In particular, polysaccharides from persimmon are known to have anti-coagulant, anti-oxidant, and immune-stimulatory activities. However, their beneficial effects against osteoporosis have not been reported. In the present study, we investigated the anti-osteoporotic effects of polysaccharides from persimmon leaves (PLE0) using an in vivo model of ovariectomy (OVX)-induced bone loss and an in vitro system of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation. In the OVX mouse model, PLE0 remarkably improved OVX-induced trabecular bone loss by suppressing osteoclast activity. In primary bone marrow-derived macrophages (BMMs), PLE0 dose-dependently inhibited osteoclast differentiation. In addition, PLE0 down-regulated RANKL-induced activation of mitogen-activated protein kinases (MAPKs) such as p38, ERK, and JNK resulting in suppression of nuclear factor of activated T cells cytoplasmic 1 (NFATc1) expression. Our results indicate that PLE0 has anti-osteoporotic effects in OVX-induced bone loss via inhibition of osteoclast differentiation. Taken together, PLE0 from persimmon may prevent postmenopausal bone loss and osteoporotic bone fragility.

Enzyme-assisted extraction, chemical characteristics, and immunostimulatory activity of polysaccharides from Korean ginseng (Panax ginseng Meyer).

In this study, enzyme-assisted extraction was used to isolate functional polysaccharides from Korean ginseng (Panax ginseng Meyer) and the physicochemical and biological properties of the extracted polysaccharides were investigated, comparing with those from traditional hot-water extraction (FGWP). In macrophages, their effects on cytokines production could be ordered as FGEP-CA ≥ FGEP-A > FGEP-C > FGWP, suggesting that FGEP-CA (combined cellulase- and α-amylase-extracted polysaccharide) is a potent immunostimulator. In addition, enzymatic digestion led to differences in the monosaccharide profile of the extract. FGWP mainly consisted of rhamnose, arabinose, galactose, galacturonic acid, and glucose in molar percentages of 1.8:10.1:9.2:17.8:60.6, whereas FGEP-CA was 3.2:11.4:16.5:22.3:45.8, respectively, suggesting that enzyme-assisted extraction of ginseng polysaccharides produces a higher proportion of pectin polysaccharides. The HPLC profile of FGEP-CA also showed lower and more heterogeneous molecular weights than FGWP did. In cyclophosphamide-induced immunosuppressed mice, FGEP-CA administration ameliorated decreased spleen and thymus indices (200 mg/kg), lymphocyte proliferation, natural killer cell activity, leukocyte counts, and the serum cytokines, interleukin-2, interleukin-6, and interferon-γ (100 and 200 mg/kg). These results suggest that enzyme-assisted extraction using cellulase and α-amylase is an effective method for the preparation of functional polysaccharides from fresh Korean ginseng, and FGEP-CA could be utilized as a potential immune-stimulatory agent.

Mixing ratio optimization for functional complex extracts of Rhodiola crenulata, Panax quinquefolius, and Astragalus membranaceus using mixture design and verification of immune functional efficacy in animal models.

We aimed to identify the optimum mixing ratio for various ingredients to obtain complex extracts with high extract yields and immune-enhancing activity in animals. The extract yield and amounts of nitric oxide (NO) and interleukin (IL)-6 were set to maximum for modeling predictions. The predicted optimum values for the mixing ratio were 49.5% for Rhodiola crenulata, 26.1% for Astragalus membranaceus, and 24.4% for Panax quinquefolius, and the predicted response values were 31.5% yield, 13.4% NO production, and 6.1% IL-6 production; actual values were 35.3% yield, 14.7% NO, and 6.6% IL-6. The optimum mixing ratio extract (OMRE) was used for the animal experiments. Treating mice with OMRE at 200 mg/kg produced significant increases in spleen indexes and T-cell/B-cell proliferation. OMRE treatment increased IL-10 and IL-6 production in concanavalin A- and lipopolysaccharide-induced T- and B- lymphocytes, respectively. These results provide a basis for the development of functional extracts and drinks.

Molecular cloning, purification, and characterization of a novel thermostable cinnamoyl esterase from Lactobacillus helveticus KCCM 11223.

A gene encoding cinnamoyl esterase (CE), which breaks down chlorogenic acid (ChA) into caffeic and quinic acids, was cloned from Lactobacillus helveticus KCCM 11223. The gene with an open reading frame of 759 nucleotides was expressed in Escherichia coli, which resulted in a 51.6-fold increase in specific activity compared to L. helveticus KCCM 11223. The recombinant CE exists as a monomeric enzyme having a molecular weight of 27.4 kDa. Although the highest activity was observed at pH 7, the enzyme showed stable activity at pH 4.0-10.0. Its optimum temperature was 65°C, and it also possessed a thermophilic activity: the half-life of CE was 24.4 min at 65°C. The half-life of CE was 145.5, 80.5, and 24.4 min at 60, 62, and 65°C, respectively. The Km and Vmax values for ChA were 0.153 mM and 559.6 µM/min, respectively. Moreover, the CE showed the highest substrate specificity with methyl caffeate among other methyl esters of hydroxycinnamic acids such as methyl ferulate, methyl sinapinate, methyl p-coumarate, and methyl caffeate. Ca2+, Cu2+, and Fe2+ significantly reduced the relative activity on ChA up to 70%. This is the first report on a thermostable CE from lactic acid bacteria that can be useful to hydrolyze ChA from plant cell walls.

Monitoring of Yeast Communities and Volatile Flavor Changes During Traditional Korean Soy Sauce Fermentation.

Flavor development in soy sauce is significantly related to the diversity of yeast species. Due to its unique fermentation with meju, the process of making Korean soy sauce gives rise to a specific yeast community and, therefore, flavor profile; however, no detailed analysis of the identifying these structure has been performed. Changes in yeast community structure during Korean soy sauce fermentation were examined using both culture-dependent and culture-independent methods with simultaneous analysis of the changes in volatile compounds by GC-MS analysis. During fermentation, Candida, Pichia, and Rhodotorula sp. were the dominant species, whereas Debaryomyces, Torulaspora, and Zygosaccharomyces sp. were detected only at the early stage. In addition, Cryptococcus, Microbotryum, Tetrapisispora, and Wickerhamomyces were detected as minor strains. Among the 62 compounds identified in this study, alcohols, ketones, and pyrazines were present as the major groups during the initial stages, whereas the abundance of acids with aldehydes increased as the fermentation progressed. Finally, the impacts of 10 different yeast strains found to participate in fermentation on the formation of volatile compounds were evaluated under soy-based conditions. It was revealed that specific species produced different profiles of volatile compounds, some of which were significant flavor contributors, especially volatile alcohols, aldehydes, esters, and ketones.

Effects of indigenous yeasts on physicochemical and microbial properties of Korean soy sauce prepared by low-salt fermentation.

This study deals with understanding the effects of salt reduction on both the physicochemical and microbiological properties of soy sauce fermentation and also the application of indigenous yeast starters to compensate for undesirable changes occurring in salt-reduced processes. Fermentation was tested in situ at a Korean commercial soy sauce processing unit. Salt reduction resulted in higher acidity as well as lower pH and contents of residual sugar and ethanol. Moreover, undesired flavor characteristics, due to a lack of distinctive compounds, was observed. In addition, putrefactive Staphylococcus and Enterococcus spp. were present only during salt-reduced fermentation. To control these adverse effects, a single or mixed culture of two indigenous yeasts, Torulaspora delbrueckii and Pichia guilliermondii, producing high ethanol and 3-methyl-1-butanol, respectively, were tested. Overall, all types of yeast applications inhibited undesirable bacterial growth despite salt reduction. Of the starter cultures tested, the mixed culture resulted in a balance of more complex and richer flavors with an identical flavor profile pattern to that obtained from high salt soy sauce. Hence, this strategy using functional yeast cultures offers a technological option to manufacture salt-reduced soy sauce while preserving its typical sensory characteristics without affecting safety.

Exopolysaccharide produced by Pediococcus acidilactici M76 isolated from the Korean traditional rice wine, makgeolli.

This work is aimed to increase knowledge of the functional exopolysaccharide (EPS) from lactic acid bacteria (LAB) in makgeolli, a Korean fermented rice wine. Among LAB strains isolated from makgeolli, strain M76 was selected as a functional strain producing a bioactive EPS, based on its antioxidative activity on the DPPH radical. The 16S rRNA gene sequencing analysis showed a high sequence similarity (99.0%) with P. acidilactici, but had different biochemical properties with the already known P. acidilactici type strains in the aspect of carbohydrates utilization. The obtained P. acidilactici M76 produced a soluble EPS above 2 g/l. One-step chromatography using gel filtration after ethanol precipitation from the supernatant of P. acidilactici M76 was enough to obtain purified EPS with a single peak, showing a molecular mass of approximately 67 kDa. Componential and structural analyses of EPS by TLC, HPLC, and FT-IR indicated that the EPS is a glucan, consisting of glucose units. The purified EPS had antioxidant activity on the DPPH radical of 45.8% at a concentration of 1 mg/ml. The purified EPS also showed proliferative effect on the pancreatic RIN-m5F cell line and remarkable protection activity on alloxan-induced cytotoxicity. This potent antioxidant and antidiabetic EPS by LAB in makgeolli may contribute to understanding the functionality of makgeolli.