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1.
The various extracts from chamdanggui (Angelica gigas Nakai) and sogdan (Phlomis umbrosa Turcz) were evaluated for estrogenic activity and characterized according to HPLC profile. Chamdanggui and sogdan were individually extracted with 4 solvents (hot water, 70% ethanol, n-butanol, and dichloromethane) of differing polarities. Estrogenic activity was determined by E-screen using an estrogen-dependent MCF-7 BUS cell. Although almost all extracts showed estrogenic effects in a concentrationdependent manner, the hot water extract from chamdanggui (250 μg/mL) had the higher effect (138%). Among 90 fractions using HPLC separation of the hot water extract from chamdanggui, fraction 21 and 28 produced the highest estrogenic effects of 178 and 163% at 10 μg/mL, respectively. The results imply that the hot water extract from chamdanggui could be useful as an alternative hormone replacement therapy.  相似文献   

2.
The pH of red ginseng extracts fermented with Saccharomyces cerevisiae and Saccharomyces carlsbergensis decreased rapidly during 3 days of fermentation, with no further significant change thereafter. After 20 days of fermentation, a relatively small difference remained in the acidity of extracts fermented with S. cerevisiae (0.54%) and S. carlsbergensis (0.58%). Reducing sugar in the S. cerevisiae and S. carlsbergensis extracts decreased from 258.6 to 45.4 and 43.2 mg/mL glucose equivalents, respectively; and ethanol contents increased from 1.5% at day 0 to 16.0 and 15.0%, respectively, at day 20. Ginsenosides Rb1, Rb2, Rc, Re, Rf, and Rg1 decreased during the fermentation with S. cerevisiae, but Rd and Rg3 increased by day 12. Ginsenosides Rb1, Rb2, Rc, Re, and Rg1 decreased gradually in the extract with S. carlsbergensis, but Rd and Rg3 were increased at day 6 and 9, respectively.  相似文献   

3.
Bacillus species were screened to be used as starters for jeotgals, salted and fermented Korean sea foods. A strain, JS2, showing strong fibrinolytic activity was isolated from saeu (small shrimp) jeotgal, and identified as Bacillus subtilis. Bacillus subtilis JS2 grew well at 20% (w/v) NaCl concentration. SDS-PAGE of culture supernatant from JS2 showed 3 major bands of 27, 29, and 60 kDa in size. Fibrin zymography showed that the 27 kDa band was the major fibrinolytic protein. The gene, aprEJS2, was cloned and introduced into B. subtilis WB600 using pHY300PLK. A B. subtilis transformant harboring pHYJS2 showed higher fibrinolytic activity than B. subtilis JS2. aprEJS2 was overexpressed in Escherichia coli BL21 (DE3). The optimum pH and temperature for AprEJS2 were pH 8.0 and 40 °C, respectively. Km and Vmax values were determined. AprEJS2 has strong α-fibrinogenase activity and moderate β-fibrinogenase activity.  相似文献   

4.
The aim of this paper was to study the biogenic amines (histamine, tyramine, putrescine, cadaverine, agmatine, spermine and spermidine) production of selected technological important lactic acid bacteria (strains of the genera Lactococcus, Lactobacillus and Streptococcus). Three methods (ion-exchange chromatography (IEC), PCR and cultivation method with pH indicator) were used. Within the 39 strains of lactic acid bacteria tested, the production of tyramine (formed by tyrosine decarboxylase) was detected in eight strains (3 strains of Lactococcus lactis subsp. lactis, three strains of Lactococcus lactis subsp. cremoris, 1 strain of Streptococcus thermophilus and 1 strain of Lactobacillus delbrueckii subsp. bulgaricus). The other tested biogenic amines were not detected. Cultivation in decarboxylation broth seems to be the least accurate method for the detection of biogenic amines due to enhanced risk of false-positive reactions. Therefore, in order to detect bacteria producing biogenic amines, the combination of PCR and chromatographic methods (e.g. IEC) can be recommended.  相似文献   

5.
Probiotic characteristics of Bacillus subtilis P223 isolated from kimchi were investigated in this study. Spore cells of B. subtilis P223 showed high tolerance to artificial gastric juice (pH 2.5, 0.3% pepsin, 3 h) and bile salts (0.3% oxgall, 24 h). Spore cells of B. subtilis P223 showed more adherence to intestinal cells (HT-29 cells) than vegetative cells. In addition, B. subtilis P223 showed high autoaggregation ability, similar to a commercial strain (Bacillus clausii ATCC 700160). Moreover, its coaggregation abilities with pathogens were strong. The adherence of three pathogens (Salmonella enteritidis ATCC 13076, Listeria monocytogenes ATCC 15313, and Escherichia coli ATCC 25922) to HT-29 cells was inhibited by B. subtilis P223. It was found that B. subtilis P223 could not produce β-glucuronidase, a carcinogenic enzyme. However, it had amylase and protease activities. Antibiotic susceptibility was measured using disk diffusion assay. It was revealed that B. subtilis P223 was only resistant to streptomycin among eight kinds of antibiotics. In addition, B. subtilis P223 showed no hemolysis activity. It did not have enterotoxin genes. Results of this study suggest that B. subtilis P223 isolated from kimchi has potential as a probiotic strain.  相似文献   

6.
In the present study, the disinfection efficacy of slightly acidic electrolyzed water (SAEW) and strongly acidic electrolyzed water (AEW) was tested on three bacteria, Escherichia coli, Staphylococcus aureus, and Bacillus subtilis and the disinfection mechanism was discussed. The results showed that SAEW had a stronger antibacterial efficacy against these tested bacteria in comparison with AEW. The results also showed that both SAEW and AEW treatments could damage the cell membrane, which was demonstrated microcosmically by scanning electron microscopy (SEM), thus causing leakages of protein, DNA, RNA, and ATP, resulting in the death of microbes. Moreover, AEW treatment could not cause the degradations of DNA and RNA, and nucleic acids including DNA and RNA are not the target point of its bactericidal efficacy. However, SAEW could maybe cause the degradation of RNA, and RNA may be the target in its antibacterial activity. We suggested that the differences in antibacterial efficacy between SAEW and AEW could be explained by the different impacts on RNA of tested strains.  相似文献   

7.
Single-layered particleboards were produced from granulated Quercus cerris bark containing cork and phloem granules using standard hot-press equipment and phenol–formaldehyde resin. The experimental boards were tested for thickness swelling, mechanical strength and thermal properties. Scanning electron microscopy observations were carried out to analyze the panel structure. The results showed that Q. cerris bark particleboards had low thickness swelling in water, high resistance to thermal degradation and high calorific values but their mechanical strength was below that of commercial wood particleboards. The produced Q. cerris bark particleboards were adequate for exterior applications where mechanical strength is not the key factor. Potential for process and feedstock optimization was acknowledged.  相似文献   

8.
Food allergy has becoming the serious threat in the world for which the search of an effective anti-allergic drug is the demand of time. Keeping in view of the potentiality of seaweeds, the ethanol extracts from Sargassum tenerrimum (ST), Sargassum cervicorne (SC), and Sargassum graminifolium turn (SG) have been studied in vivo for its antiallergenicity through passive cutaneous anaphylaxis (PCA) and active cutaneous anaphylaxis (ACA) in female BALB/c mice. Intraperitoneal administration of these ethanol extracts inhibit mouse PCA and ACA in a dose-dependent manner using ovalbumin (OVA) and shrimp allergen as triggering agents to induce allergenicity over mice. The extract of ST containing phlorotannin has been found most active over the suppression of PCA triggered by OVA and shrimp with IC50 values of 25.64 and 40.98 mg/kg, respectively and an efficacy comparable to that of an anti-allergic drug disodiumcromoglycate. Similarly, ST inhibits ACA triggered by ova and shrimp allergen in the mouse, with 50% suppression at 25.5 and 43.53 mg/kg, respectively. The results presented here show that these extracts are active on the studied models among which ethanol extract of ST was the most potent, leading toward the promising development of a new class of anti-allergic drugs.  相似文献   

9.
Lactic acid bacteria (LAB) are key for the fermentation of sourdoughs to improve the quality and nutritive value of bread. The aim of this study was to isolate the LAB starter for sourdough fermentation from Jeung-pyun, a Korean traditional rice cake. Among the twenty two LAB screened, five isolates were selected based on exo-polysaccharide production. Among them, three isolates showed cell growth greater than 8.5 Log CFU/g, maximum increase in the volume of dough, and dextran concentration up to 0.16%. During the sourdough fermentation, pH and total titratable acidity (TTA) were changed, as the three isolates synthesized lactic acid and acetic acid with fermentation quotients less than 2.0. They were identified as Leuconostoc lactis EFEL005, Lactobacillus brevis EFEL004, and Le. citreum EFEL006. They displayed good fermentation properties (growth, dextran production, pH, and TTA) in dough and they are regarded as potential starters to be used in sourdough fermentation.  相似文献   

10.
The diversity of 87 Lactobacillus paracasei and Lactobacillus plantarum/paraplantarum strains, previously identified from different autochthonous dairy products, was investigated by phenotypic and genotypic approaches. The increased resolution obtained using phenotypic and genotypic characterization allowed the level of strain heterogeneity detection to be widened. Phenotypic diversity was evaluated by studying biochemical characteristics of technological interest, including antimicrobial and proteinase activities, resistance to nisin, aggregation ability, production of exopolysaccharides, acetoin and diacetyl, citrate utilization, and antibiotic susceptibility. Genotypic diversity was generally evaluated by PCR amplification of repetitive bacterial DNA element fingerprinting using the (GTG)5 primer [(GTG)5-PCR]. Moreover, in cases where strains were not discriminated by (GTG)5-PCR combined with phenotypic analysis, pulsed-field gel electrophoresis (PFGE) analysis was performed. The results indicate that L. plantarum/paraplantarum and L. paracasei natural isolates from artisanal dairy products are a gold mine in terms of diversity of strains and could be potentially interesting to dairy companies for the formulation of functional starter cultures in the production of innovative foods.  相似文献   

11.
The aim of this study was to investigate the fermentation behaviour, antioxidant activity and rheological behaviour of the sourdoughs prepared with Lactobacillus helveticus and Kluyveromyces marxianus. The final acidity of the sourdough after 18 h of fermentation was higher at higher temperatures (40 °C) and for the formulations with whole rye flour. The highest lactic/acetic acid ratios were obtained in case of more fluid sourdoughs fermented at 40 °C. The antioxidant properties of the sourdoughs are correlated with metabolic activity of the microorganisms, the DPPH radical scavenging activity being higher for optimum conditions of Lactobacillus helveticus growth. On the other hand, the rheological properties of the sourdoughs are not significantly influenced by the temperature. Sourdoughs formulations with whole flour are more viscous, as well as the controls fermented by the spontaneous microflora. The results of the bread-making process simulation by means of Mixolab indicate differences between dough formulations mainly depending on flour type.  相似文献   

12.
Structural and rheological characterization of reconstituted hydrogels developed from A. vera non-fibrous alcohol insoluble residue (NFAIR) powder using different methods [viz., shaking (S), heating-shaking (HS), and heating (H)] and concentrations (viz., 0.2–1.6 %, w/v) was carried out. Functional group distribution by FTIR spectroscopy and Congo red (CR) method revealed the presence of acetylated acemannan in A. vera powder. Dynamic oscillation studies of A. vera (NFAIR) fluids at all concentrations of 0.2–1.6 %, w/v, showed gel strength in the order of H > HS > S method. However, in H method, increase in concentration from 0.2 to 1.6 %, w/v showed the conformational transition from semi-diluted solution to weak gel nature. Rheological models described the effect of heating temperatures (HT); 30–90 °C, and times (Ht); 15–60 min on viscoelastic behavior in reconstituted A. vera fluids. The reconstituted A. vera hydrogel prepared with a concentration of 1.6 %, w/v using 50 °C (HT) and 30 min (Ht) condition showed a good agreement with the Power law (storage modulus, G′) and Weak gel model (complex modulus, G*) fitted data (R2 > 0.94) resulting higher viscoelastic moduli intercepts; G0 (71.5 Pa s n), G0 (33.5 Pa s n), lower slopes; n′ (0.22), n″ (0.06), higher network strength (A F , 121.3 Pa s1/z ) and number of network (z, 5.3) values. The obtained results suggested that heating at 50 °C/30 min can develop aqueous weak gel networks of A. vera with enhanced gel strength which may be utilized as a novel gelling agent for wide variety of targeted applications in food and pharmaceutical sectors.  相似文献   

13.
A new rapid method based on real-time PCR was developed to detect four thermophilic Campylobacter species (Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis) in food samples. The assay targeted the bipA gene for C. upsaliensis and C. lari, whereas the gene encoding the ATP-binding protein CJE0832 was used to detect C. coli and C. jejuni. These genes were chosen for this assay due to their low variability and mutation rate at a species level. The multiplex PCR showed 100% inclusivity for all 25 thermophilic Campylobacter strains tested and 100% exclusivity for 38 non-targeted strains belonging to closely related species. The newly developed real-time PCR could detect down to 102 genomes/reaction and displayed efficiency above 97% for all species except for C. upsaliensis (90.1%). The method proved to be a reliable tool for food analysis, showing 100% sensitivity, 96% efficiency, and 92.45% specificity when validated against the gold standard method UNE-EN ISO 10272:2006 using 200 diverse food samples (meat, fish, fruits and vegetables, and raw milk). In artificially spiked samples, the detection limit of the method was 10 cfu/g in salad, 5 cfu/g in turkey meat, and 1 cfu/g in the rest of meat samples tested. Consequently, the newly designed molecular tool represents a quick and safe alternative to obtain reliable results concerning the presence/absence of the main thermophilic Campylobacter in any food sample.  相似文献   

14.
Thermal inactivation of quality-related enzymes in both cauliflower crude enzyme extracts and fresh tissue samples was studied in temperature range 50–100 °C. For crude enzyme extracts, several parameters, reaction rate constants (k) and activation energy (E a) as well as decimal reduction time (D) and (z) values, were used to characterize the thermal stability. The rates of inactivation were found to follow first-order inactivation kinetics. Activation energies varied between 101.18 and 208.42 kJ mol−1 with z values of 10.59–24.09 °C. The examined kinetics indicated that lipoxygenase was the most heat resistant followed by peroxidase, polyphenol oxidase, pectin methyl esterase and ascorbic acid oxidase. Furthermore, the obtained results from the blanched fresh tissues indicated that inactivation of lipoxygenase secured disappearing of any other enzyme activities. Therefore, this study recommends using lipoxygenase as an indicator enzyme to optimize the thermal treatments of cauliflower products.  相似文献   

15.
16.
The histidine decarboxylating activity and production of biogenic amines by Morganella morganii (NCIMB, 10466), Klebsiella pneumoniae (NCIMB, 673) and Hafnia alvei (NCIMB, 11999) were investigated using a rapid HPLC method. Derivatisation of the bacterial samples was carried out using benzoyl chloride. A gradient elution system was used for analysis with a mixture of acetonitrile and HPLC grade water. Bacterial strains not only produce histamine in histidine-enriched broth but also the other biogenic amines. The chromatographic results show that bacterial strains are also capable of producing spermine and spermidine in histidine-enriched broth. Bacterial ammonia production by all three strains was clearly detected since ammonia is generated during the degradation of histidine. The study demonstrates that the highest histamine production was obtained by Morganella morganii, followed by Klebsiella pneumoniae, and the lowest with the Hafnia alvei. Therefore, Morganella morganii and Klebsiella pneumoniae have strong histidine decarboxylase activity since they are prolific histamine-forming bacteria  相似文献   

17.
The prevalence, genetic diversity, and antibiotic susceptibility of Cronobacter species (Enterobacter sakazakii) isolated from sunshik products, its ingredients, and root vegetable farm’s soils were investigated to analyze main reservoirs and contaminated sources of Cronobacter spp. Cronobacter spp. was isolated from 9 of 15 sunshik products, 26 of 72 its ingredients, and 2 of 39 soils. The root vegetables such as sweet potato and carrot showed higher contamination rate (70%) than the other sunshik ingredients. All isolates showed 929 bp band amplified from 16S rRNA and resistant to ampicillin, amoxicillin/clavulanic acid, and cefazolin. All isolates showed diverse random-amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) band patterns. However, 3 cases of RAPD banding patterns between clinical strains and isolates from sunshik products and root vegetables (yam, carrot) were related with similarities level of 80%. These studies indicated that root vegetables can be an important contamination source of Cronobacter spp. in sunshik products. Thus, the preparation of root vegetables for manufacturing sunshik products used as a weaning diet was handled with more care than the other sunshik ingredients.  相似文献   

18.
The effect of the potentially probiotic bacteria strain of Lactobacillus acidophilus Bauer and probiotic bacteria Bifidobacterium animalis ssp. lactis BB12 on proteolytic changes of proteins in dry-cured loins during fermentation and cold storage was studied. Results of the conducted tests demonstrated that the use of probiotic bacteria for the production of dry-cured meats impacts the generation of products of protein proteolysis with high antioxidant activity. The highest antioxidant activity of peptides after fermentation and cold storage was observed in the loin with the strain B. animalis ssp. lactis BB12 and the loin with the mixture of strains L. acidophilus Bauer and B. animalis ssp. lactis BB12. Qualitative analysis of peptides demonstrated that peptides with weight below 3.5 kDa are characterized by the highest capacity of quenching the ABTS cation radical, including the peptides in loins with the strain B. animalis ssp. lactis BB12.  相似文献   

19.
The objective of this study was to select and identify yeasts and molds isolated from traditional nuruk and to investigate their brewing characteristics for Cheongju production. The yeast strains Y190 (Accession ID-KACC 93251P), Y263 (Accession ID-KACC 93252P), and Y270 (Accession ID-KACC 93253P) showing high alcohol and flavor productivity were isolated and identified by phylogenetic inference based on an internal transcribed spacer 2 region sequence analysis. In addition, Aspergillus oryzae 83-10 (Accession ID-KACC 93254P) showing the highest enzyme activity was isolated. This study provides basic data for the production of Korean Cheongju and assesses the applicability of these three yeast strains and A. oryzae 83-10 isolated from traditional nuruk.  相似文献   

20.
Fagopyrum esculentum (buckwheat) soksungjang is one of the traditional soybean pastes in Korea. This study profiled and compared volatile compounds between traditionally manufactured (TBS) and commercially modified buckwheat soksungjang (CBS) according to their fermentation periods. More volatile compounds were generated and non-uniform increases or decreases in volatiles were more common during TBS fermentation. In addition, the changes in and differences between the volatiles from TBS and CBS during the fermentation process (after 0, 1, 2, and 5 weeks) were investigated in partial least squares-discriminant analysis models. The changes were accelerated during CBS fermentation in comparison with TBS fermentation. Several major volatile compounds, such as methyl decanoate, 3-hydroxy-2,6-dimethylpyran-4-one, and methyl heptanoate were found in the final stage of fermentation in TBS, in contrary, tridecane, (Z)-hex-3-en-1-ol, furan-2-carbaldehyde, and ethyl tetradecanoate were contributed to the latest of fermentation in CBS.  相似文献   

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