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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 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   

3.
Four types of meju were made from 100%(w/w) defatted soybean (DFS), a mixture of 80%(w/w) defatted soybean, and 20%(w/w) glasswort (DFS-G), a mixture of 80%(w/w) defatted soybean and 20%(w/w) rice (DFS-R), and a mixture of 60%(w/w) defatted soybean, 20%(w/w) glasswort, and 20%(w/w) rice (DFS-GR). Four types of Korean traditional soy sauce were prepared from the 4 types of meju. Mineral and antioxidant contents in the soy sauce made of DFS-G and DFS-GR were significantly higher than others. Citric, malic, succinic, lactic, and pyroglutamic acid contents in soy sauce made of DFS-R and DFS-GR were 1.3–1.5 times higher than others. Total nitrogen and free amino acid contents in soy sauce were correlated with DFS concentration in the meju. The bacterial community in the non-fermented meju-making ingredients was replaced largely by Bacillus sp. in the fermented meju. The use of glasswort and rice in the meju-making process did not alter the bacterial community responsible for the fermentation of meju.  相似文献   

4.
Long-term aging of Yakju, a traditional Korean liquor made of rice and Nuruk (a fermentation agent), causes browning and odor and flavor development. This study investigated the effects of heat-treated Nuruk (50–80 °C, 30 min) on Yakju quality. The saccharogenic powers and glucoamylase, α-amylase, and carboxypeptidase activities were similar in non-heat-treated Nuruk and that treated at 50 °C. However, acidic protease and alcohol dehydrogenase decreased above 50 °C. The content of nitrogen-containing compounds was inversely proportional to the heat-treatment temperature. Compounds that cause off-flavors decreased at 50–60 °C, but increased at 70–80 °C, whereas compounds that provide fragrance increased at 50–60 °C. Sensory evaluation indicated that bad taste attributes were higher in Yakju produced using non-heat-treated Nuruk. Therefore, heat treatment of Nuruk at 50 °C can be adopted as a method for improving Yakju quality, as enzymatic activities that affect color, aroma, and taste are regulated.  相似文献   

5.
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   

6.
Isotherms of shiitake mushroom (Lentinus edodes) at 25 and 40°C were determined and drying kinetics of whole and sliced shiitake mushrooms were tested using a convective air drying method at different drying temperature of 40, 50, 60, and 70°C. The monolayer moisture contents of the mushroom were 7.23 and 5.44 g water/100 g of dry solids at 25 and 40°C, respectively. Both mushroom samples showed falling drying rate periods with increasing drying rates with increases in drying temperature, and the drying rate of the sliced mushrooms was faster than that of the whole mushrooms at the same drying conditions. The kinetic parameters for dehydration of the mushrooms were determined using the Newton model and the Classical diffusion model. Activation energy (E a ) values as determined using the Newton model were 22.58 and 20.48 kJ/mol for the whole and sliced mushrooms, respectively.  相似文献   

7.
The heavy metal contents and chemical compositions among mackerel species were investigated. Atlantic and chub mackerel had higher mercury, but lower lead than blue mackerel. Chub mackerel had the highest crude fat (18.62%) and the lowest moisture (58.29%), whereas blue mackerel had the highest moisture (70.10%) and the lowest crude fat (2.89%). Atlantic and blue mackerel had total saturated fatty acids (SFA)>polyunsaturated fatty acids (PUFA)>monounsaturated fatty acids (MUFA), whereas chub mackerel had PUFA>SFA>MUFA. The main SFA of the 3 mackerels were 16:0 and the main PUFAs were 22:6n-3 and 20:5n-3. The total amino acid contents in Atlantic, blue, and chub mackerel were 190.63, 169.49, and 172.97 mg/g, respectively. The major amino acids of the 3 mackerels were glutamic acid, aspartic acid, lysine, and leucine.  相似文献   

8.
‘Lemon Myrtle’ is becoming increasingly popular in Europe both for use in cuisine and phytotherapy. However, this common name covers two completely different species, Backhousia citriodora F. Muell. and Leptospermum citratum Challinor, Cheel & A.R.Penfold. These species differ with respect to secondary compounds and even can cause, if mixed up and applied in high dose, toxic effects. We describe how the two species can be discriminated microscopically making use of differences in the morphology of leaf pavement cells and the relative size of palisade parenchyma. Based on the large subunit of ribulose-1,5-bisphosphate carboxylase oxygenase (rbcL) as molecular marker, the phylogenetic position of the two species within the Myrtaceae could be clarified. This sequence information was used to develop a simple assay to discriminate the two species even in dried and highly fragmented mixtures as typically occurring in commercial samples. This assay utilises the occurrence of single-nucleotide exchanges between those species that produce different fragments when the rbcL amplificates are restricted with Sac II.  相似文献   

9.
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   

10.
11.
The aim of this study was to investigate the effect of low-pressure cold plasma (LPCP) on the inactivation of Escherichia coli and Listeria innocua on fresh-cut apple skin and its influence on wettability. Cold plasma treatments have shown to be effective to decontaminate foods, but their effect on the wettability has not been well studied. Surface-inoculated apple samples were treated with argon (Ar), nitrogen (N2), oxygen (O2), and argon-oxygen (Ar-O2) cold plasma using a commercial LPCP unit. Three different models were used to fit bacterial survival curves after the LPCP treatments. Changes in surface wettability were also determined by measuring the contact angle. The LPCP treatments using Ar, O2, or Ar-O2 mixture for 20 min were the most effective to inactivate E. coli with O2, while the LPCP treatment with N2 for 20 min reduced L. innocua the most for (p?<?0.05). The highest increase in surface wettability was observed in samples treated for 20 min with O2 and Ar-O2. Different LPCP treatments have not great effectivity on the inactivation of E. coli and L. innocua on fresh-cut apple surface, but the all treatments changed the surface wettability of apples, making it more hydrophilic. This can be considered as a negative effect of the LPCP treatment because it can facilitate the adhesion and proliferation of re-contaminating microorganisms. More research should be undertaken to explore the use of other gases and complex surfaces.  相似文献   

12.
To acquire the effectiveness of oral treatments, aqueous extracts of Anodonta woodiana (HB) were incorporated into liposome and its antitumor activities evaluated in vivo. The HB-loaded liposomes (HBL) were prepared at a mean size of 14.85 μm by reverse-phase evaporation method. Referring to the maximum tolerated doses test, mice with orally administrated HBL, at a 3 g/kg body weight dosage, showed no obvious acute toxic sign. Furthermore, the tumoricidal activities of HBL against C26 murine colon carcinoma, Lewis lung tumor, human QGY hepatic carcinoma and MKN-45 gastric tumor were examined, respectively. In contrast to free HB, HBL possessed remarkable antitumor activity. Simultaneously, the effect of HBL was observed in a dose-dependent manner. For C26 murine colon carcinoma and Lewis lung tumor, the inhibitory ratios of HBL were 54.36 and 51.97% at a dose of 400 mg/kg, respectively. The suppression of tumor growth and the reduction in body weight were more pronounced in human QGY hepatic carcinoma and MKN-45 gastric tumors inoculated mice by treatment of HBL during 30 days. All these promising results implied that liposome-incorporated aqueous extracts of Anodonta woodiana had a more potential application as a natural antitumor and immunomodulator formulation.  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.
Fish protein hydrolysates (FPHs) were prepared from freshwater carps (Catla catla, Labeo rohita, and Cirrhinus mrigala) using flavorzyme at different degrees of hydrolysis (DHs) ranging from 5 to 20%. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging activity of the FPHs prepared from the three species were in the range of 50–82%; the ferric reducing power of the FPHs prepared from catla was the highest. The linoleic acid peroxidation inhibition activity of the prepared FPHs varied from 71 to 91%. The emulsion activity index of the FPHs prepared from catla and rohu decreased significantly with an increase in the DH (p < 0.05). The emulsion stability index of the FPHs prepared from the three species was the highest at 20% DH. FPHs prepared from freshwater carps possess good antioxidant and surface-active properties and are therefore suitable to be used as natural antioxidants in health-food formulation and as water-soluble antioxidants in the food-processing industry.  相似文献   

15.
We investigated the composition of muscle tissue from 30 untreated striped catfish (Pangasianodon hypophthalmus) and 40 untreated pikeperch (Sander lucioperca). The analyzed fillets had a mean moisture level of 77.5 % in striped catfish and 78.7 % in pikeperch. The mean level of protein content was 19 % in striped catfish and 20.5 % in pikeperch; the pH was 6.5 in striped catfish and 6.8 in pikeperch. Our data provide a first basis on a legal opinion concerning fishery products that are suspected to contain high amounts of added water. These data can also be used for the calculation of added water regarding the regulation of the European Union (EU) No 1169/2011, provision of food information to consumers.  相似文献   

16.
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   

17.
The aim of this research was to investigate the levels of phenolic compounds and antioxidant activities in different tissues including leaves, stems, and roots from baekseohyang (Daphne kiusiana). The highest contents of total phenolics (43.59 mg gallic acid equivalent, GAE/g) and flavonoids (15.73 mg rutin equivalents, RE/g) were observed in the 75% methanol extract of leaves. Moreover, this extract had the predominant antioxidant capacity, DPPH (85.91%) and ABTS (92.57%) radical scavenging activities as well as reducing power (7.20%) at a concentration of 5 mg/mL. The highest content of phenolic compounds was also exhibited in this extract with an increasing order in leaves, roots, and stems and their major components were vanillic acid (6.37 mg/g), tannic acid (1.91 mg/g), and p-hydroxybenzoic acid (3.96 mg/g). Thus, the strong antioxidant activities of the 75% methanol extract are correlated with high phenolic compound contents. This study suggests that baekseohyang leaves may potentially be used as an accessible source of natural antioxidants.  相似文献   

18.
S. cerevisiae proteinase A (PrA) is a member of the aspartic proteinase superfamily. The roles of PrA in S. cerevisiae physiology and cell metabolism are controversial. The objective of the current study was to elucidate the effects of the absence of PrA on key enzymes with regard to the glycolytic flux in industrial S. cerevisiae. The observed activities of hexokinase (HK), phosphofructokinase (Pfk) and pyruvate kinase (PYKi) in PrA-modified S. cerevisiae strains (SC2 and SC3) were lower than that of the wild-type strain (p < 0.01). Compared to other strains, SC3 revealed the lowest activity of three key glycolytic enzymes. Current results imply that PrA in industrial S. cerevisiae may control the glycolytic enzymes expression (HK, Pfk and PYKi) in the direct or indirect manner and thus lead to the delay of cell metabolism. The observed intracellular ATP levels between the wild-type strain and PrA-modified strains (SC1 and SC2) were significantly different (p < 0.01). The pronounced differences of key glycolytic enzymes between the wild-type and PEP4-modified strains were as well characterized by SDS–PAGE. The intracellular protein concentration in the presence of PrA is higher than those of the PrA-modified strains. As a result, the interaction mode of PrA and the glycolytic enzymes was postulated in this work. The findings herein suggest that the glycolytic flux direction and rate may be regulated by vacuolar PrA in industrial S. cerevisiae. The present data obtained provide insights into understanding the roles of PrA in industrial S. cerevisiae.  相似文献   

19.
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   

20.
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   

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