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1.
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   

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3.
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   

4.
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   

5.
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   

6.
Green tea has been credited with providing a wide variety of health benefits like higher total antioxidant, cancer prevention, and anti-irritant etc. Microencapsulation technology is used to prevent antioxidant loss during processing which involves entrapment of active material into carrier material. The experiments were designed using response surface methodology based on three level two factor (green tea extract, 10–25 % and drying inlet air temperature, 120, 130 and 140°C) central composite design. The feed emulsion was prepared with green tea extract as core material and 40 % maltodextrin concentration as wall material with the ratio of core to wall (1:2) and it was fed into the spray dryer at varied drying inlet air temperature to get encapsulated green tea extract powder. The quality characteristics were analysed such as moisture content, total antioxidant activity and total phenolic content and the process conditions were optimized using desirability function methodology. At optimum spray drying condition moisture content, total antioxidant activity and total phenolic content were found to be 3.1 % w.b., 72.91 % free radical scavenging activity by DPPH method, 57.81 mg/g of dry matter, expressed as gallic acid equivalent respectively with desirability value of 0.92.  相似文献   

7.
The influence of operational conditions (pH, stirrer speed, and temperature) used in the process of xanthan production by Xanthomonas axonopodis pv vesicatoria (XCVA3-1) isolated from pepper plant were evaluated through yield of xanthan and compared with control strain Xanthomonas campestris NRRL-B 1459. Different conditions used during the fermentation affected the xanthan production. In this study the best combination of yield was obtained, reaching 1.325 g/100 mL with the use of pH 7.0, 30°C, and 250 rpm during fermentation. Increased yield of xanthan production can be obtained at high agitation values, with the maximum at 400 rpm. Higher yields of gum production can be obtained at 30°C and the optimum pH was found 7.0. This results were similar for the X. campestris NRRL-B 1459.  相似文献   

8.
Wholemeal samples were obtained from five durum wheat cultivars at two different bug (Eurygaster spp.) damage levels (medium and high damage). The samples were incubated (60 and 120 min) and used in size exclusion high performance liquid chromatography (SE-HPLC) analyses. The results showed that the amount of larger polymeric protein (TP1) and smaller polymeric protein (TP2) obtained from total (sodium dodecyl sulfate soluble) proteins decreased significantly in the bug-damaged samples, while the amount of total larger monomeric proteins (TP3) increased. The polymeric/monomeric protein ratio of all cultivars decreased at 60 min of incubation with increasing damage level. For all cultivars, the ratio of unextractable polymeric protein (UPP%) significantly decreased at 60 min of incubation except cv. Diyarbakir. The results suggested that bug protease caused depolymerization and/or disaggregation of polymeric proteins to lower their average molecular size. The changes in protein structure as determined using SE-HPLC supported by the decreases in gluten content and gluten index values which decreased with suni-bug damage. Deteriorative effects of bug damage on durum wheat quality were found to be quite similar to those on bread wheats.  相似文献   

9.
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   

10.
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   

11.
This study dealt with the production and characterization of gelatin nanospheres and encapsulation with Momordica charantia, commonly known as bitter gourd fruit vegetable extract (BGE). The impact of encapsulation and increasing the encapsulate loading on various physiochemical characteristics of gelatin polymeric entities as well as antioxidative attributes of BGE was studied. Nanospheres were formed via an electrospraying process conducted at 20 kV, 0.5 mL/h, and 10 cm of voltage, flow rate, and emitter/collector distance, respectively. The spherical beads were encapsulated with BGE at 5 to 15% (w/w%) loading rate. Morphological analysis through scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated that nanospheres could be successfully produced. Furthermore, nanosphere encapsulation of the extract was demonstrated in transmission electron microscope (TEM) micrographs. Spectroscopic analysis indicated no chemical interactions between core and wall materials. The thermal stability of encapsulated nanoparticles slightly increased and the glass transition temperature (Tg) disappeared due to increased crystallinity. Thermogravimetric graphs of encapsulated spherical beads, at all core loadings, showed an additional phase ranging from 138 to 249 °C, overlapping with the BGE’s main TGA degradation phase. The presence of this phase, which was absent from empty bead thermograms, confirmed encapsulation occurrence during electrospraying process. Furthermore, an average of 80% of antioxidative content and potency of the extract was conserved during the encapsulation process. Moreover, phenolic content and antioxidative activity of the encapsulated extract showed higher stability than extracts while stored at refrigerated and ambient conditions.  相似文献   

12.
Response surface methodology was used to predict optimum conditions for hot air roasting of barley grains (temperature, time, and amount). Antioxidant capacity in the grains was highest under optimum conditions of 250 °C, 63.5 min and 42 g (one and a half layers). A correlation of R 2 = 0.74 (p < 0.05) was found between 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and total phenolic contents. Ethanol and aqueous extracts were prepared from grains roasted under optimum conditions and assessed for antioxidant capacity. Antioxidative compounds in the extracts were then identified using GC–MS. The IC50 value of ethanol extract was significantly lower (11.45 μg mL–1) than that of aqueous extract (33.54 μg mL–1) and α-tocopherol (12.6 μg mL–1) but higher than BHT (9.59 μg mL–1). The same trend was observed in linoleic acid assay. In reducing power, the ethanol extract and α-tocopherol were not significantly different. Phenolic acids p-hydroxybenzaldehyde, vallinic and gallic acids were identified as the major compounds in the extracts. The results obtained from this study show that it is possible to optimize antioxidant capacity in barley grains during roasting.  相似文献   

13.
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   

14.
Antagonistic activity of the mixtures Rahnella aquatilis–Rhodotorula glutinis and R. aquatilis–Cryptococcus laurentii was assessed against Penicillium expansum (cause of blue rot) and Botrytis cinerea (cause of grey rot) on apple fruit at 4 °C and 95% relative humidity (RH). Under these cold-storage conditions, the mixture R. aquatilis–R. glutinis inhibited the development of B. cinerea and P. expansum in apples stored for 40 days and reduced the incidence of disease produced by these moulds to nearly zero. The other mixture, R. aquatilis–C. laurentii, was less effective; the incidences of the grey rot and the blue rot were about 25% and 15%, respectively. Population dynamics of the mixtures showed that the growth of R. aquatilis was strongly stimulated by the presence of the yeast R. glutinis, but in the case of the mixture R. aquatilis–C. laurentii, the same effect could not be observed. In this study, it was demonstrated that the combination of two microorganisms with different requirements and antagonistic abilities resulted in a successful mixture against the two pathogen molds, B. cinerea and P. expansum. In addition, it was also proved that it is possible to improve the biocontrol of these pathogens without increasing the inoculum size of the antagonist (alone or in mixtures), which was always 106cell/ml, despite the high concentration of the pathogen (106 conidia/ml) utilized.  相似文献   

15.
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   

16.
The anthocyanins present in black carrot were extracted with pressurized water acidified with sulfuric, citric and lactic acids. Anthocyanin degradation became significant above 100 °C and there was no improvement when extraction pressure was increased to 100 bar. Therefore, the extraction from black carrot was carried out at temperatures 50, 75 and 100 °C under 50 bar pressure. The extraction efficiencies in terms of acylated and non-acylated anthocyanins were comparable for all three acids used to acidify water at 50 °C, while similar results were observed at 75 °C for both citric and lactic acids. Water acidified with lactic acid showed significantly higher extraction efficiency at 100 °C compared to water acidified with sulfuric and citric acids. Highest degree of polymerization together with increasing degree of browning was observed within extracts when sulfuric acid was used. On the other hand, when organic acids were used to acidify water, a higher extraction efficiency of anthocyanins, accompanied with a relatively low polymerization and browning was observed, with lactic acid giving the best results.  相似文献   

17.
Polysaccharides from Auricularia auricula-judae (AP) have unique functionalities. The influence of AP-blending ratios (0.1–0.8%), temperature, pH, and ionic strength on the rheological interactions of yam starch (YS)–AP blends (YA, 6%) was investigated. YA gels showed shear-thinning behavior with flow-behavior indices of 0.28–0.37 and greater pseudoplasticity in the presence of 0.8% AP. With incremental AP addition, the viscosity and consistency indices significantly increased, whereas the activation energy decreased from 7.55 to 5.12 kJ/mol (p < 0.05). YA gels exhibited excellent thickening and heat tolerance and behaved as weak gels over an AP concentration range of 0.1–0.4% but as true gels at higher concentrations (e.g. 0.8%). The viscosity/elasticity of the combinations weakened with NaCl addition or extreme pH values. A complex 3-dimensional network structure of the YA system was confirmed by scanning electron microscopy. These results indicated that AP has great potential for functional applications in the starchy food industry.  相似文献   

18.
To evaluate individual variations in broccoli VOLTA F1 plants, the bioactive components of 15 florets that were cultivated in identical agricultural and climatic conditions were analyzed. Glucosinolates were analyzed by HPLC; total phenolic compounds, ascorbic and dehydroascorbic acids (vitamin C) and the DPPH and OH radical-scavenging activities of samples were also determined. Florets were characterized by particularly high glucoraphanin content, 17.95 μmol/g dry weight on average, which comprised about 50% of total glucosinolates. High individual variation was observed for several bioactive compounds, as well as for DPPH and OH radical-scavenging activity. Coefficients of variability (CVs) were high, and except for one case, exceeded 10%. Among glucosinolates, the highest CVs were noted for progoitrin (34.22%), 4-hydroxyglucobrassicin (27.32%) and neoglucobrassicin (24.44%). High CVs were also observed for vitamin C (29.11%), including dehydroascorbic acid (26.72%), and for OH (25.76%) and DPPH (21.77%) radical-scavenging activities. Smaller variations were found for glucoraphanin (CV = 14.84%) and polyphenols (CV = 14.95%).  相似文献   

19.
This study aimed to assess the effect of sous vide cooking on the total and resistant starch content, color, and shear force in three potato cultivars (Agria, Agata, and Carrera). Potato strips were also cooked by three common treatments (boiling, frying, and microwaving) to evaluate the differences between the methods. According to principal component analysis (PCA), sous vide-processed cv. Agria and Agata potato strips were grouped with boiled samples, in contrast, cv. Carrera sous vide samples were grouped with microwaved samples. Higher water losses were associated with microwaved potatoes due to the diffusion of water inside the tuber. In addition, a significant decrease in shear force was obtained after microwaving and sous vide cooking (p < 0.05) irrespective of the treatment strength. The three cultivars became less bright, and the intensity of the color decreased; however, variations in the cook value (C 100, min) between treatments did not affect the lightness and hue angle. Regardless of the initial value of resistant starch and the intensity of the cooking process, all of the cultivars reached a final content of less than 5%. From our results, in-pack sterilization may be considered for application in the food industry as a technology that has a similar impact to conventional cooking treatments used on potato products.  相似文献   

20.
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   

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