1,721,024 research outputs found
Optimal Culture Conditions on the Tyrosinase Inhibitor Production by Actinomycetes F-97
No full textA Actinomycetes F-97 producing tyrosinase inhibitor was isolated from soil samples. The optimum culture condition for tyrosinase inhibitor production was investigated and the results were as follows. The best carbon source for tyrosinase inhibitor production was shown as soluble starch, the optimum concentration was 3.0%. The best nitrogen source for tyrosinase inhibitor production was shown as peptone, the optimum concentration was 0.36%. As effect of metal ions on the production of tyrosinase inhibitor, K2HPO4 was shown the best and the optimum concentration was 0.1 mM. The optimum pH and temperature was shown 7.0 and 30℃, respectively. And the highest tyrosinase inhibitor production was observed at 70 hr cultivation under optimum conditions in jar fermentor scale.open
Influences of culture medium components on the production poly(gamma-glutamic acid) by Bacillus subtilis GS-2 isolated Chungkookjang
No full textA bacterium strain GS-2 isolated from the Korean traditional seasoning food, Chungkookjang and was determined to produce large amounts of γ-PGA with high productivity when provided with simple nutrients (L-glutamic acid 2.0%, glucose 1.0%, NH4Cl 0.5%, KH2PO4 0.05%, MgSO4, 7H2O 0.01%, pH 7.0). In this study, the culture medium for this strain was optimized for the production of γ-PGA. The Bacillus subtilis GS-2 required supplementation with L-glutamic acid and other nutrients for maximal production of γ-PGA. The optimal culture conditions for γ-PGA production were a 48 hr culture time, a temperature of 33℃ and initial pH of 6.5 by rotary shaking (220 rpm). A maximum γ-PGA production of 31.0 g/ℓ was obtained with L-glutamic acid (30 g/ℓ), sucrose (the main carbon source, 30 g/ℓ), NH4Cl (the main nitrogen source, 2.5 g/ℓ), KH2PO4 (1.5 g/ℓ) and MgSO4, 7H2O (0.15 g/ℓ) in the culture medium.open
Quality evaluations of cookies containing mugwort powder
No full textThis study investigated the quality characteristics of cookies containing mugwort powder, which is well known for its
various functions and biological activity. Cookie samples were made by adding the mugwort powder at different levels
of 0%, 1%, 3% and 5%. In this study, moisture, pH, color, spread factor, hardness, antioxidant activity and sensory evaluation
of cookies were examined. The pH and moisture were increased when increasing levels of mugwort powder were used.
The L, a and b color values were significantly (p<0.001) decreased when increasing levels of mugwort powder were used.
The spread factor of the cookies was significantly (p<0.01) decreased when increasing levels of mugwort powder were used..
The hardness and DPPH radical scavenging activity of cookies were significantly (p<0.001) increased when increasing levels
of mugwort powder were used. Cookies containing 3% of mugwort powder showed the highest taste and texture scores.
The scores for Flavor and color decreased when more mugwort powder was added.open
Quality characteristics of cookies with Aloe vera L. powder
No full textAloe is an attractive potential food source because it has functional uses. It has been widely used as a well-being food
and drink. The antioxidant activity was estimated by measuring DPPH free radical scavenging activity. We investigated the
quality characteristics of cookies prepared by adding various concentrations of aloe powder (0%, 1%, 3%, 5%, all w/w)
as a substitute for flour. In this study, the DPPH free radical scavenging activity, moisture content, and hardness of cookies
significantly increased with increasing aloe powder, while the pH, spread factor and L and b values slightly decreased.
Sensory evaluation scores in terms of texture were shown to be very similar statistically, but color, flavor, taste, and overall
acceptability scores were lower than the control. As a result of this study, the quality of cookies with the addition of 1%
aloe powder were the most suitable in terms of taste, flavor, texture, and sensory properties.open
Purification and characteristics of tyrosinase inhibitor produced by actinomycetes F-97
No full textAn actinomycetes F-97 producing tyrosinase inhibitor was isolated from soil samples. Isolation and purification of tyrosinase inhibitor produced by F-97 was performed as follows: IRC-120 (NH4+ type) column chromatography, silica gel column chromatography, C18 column chromatography and Sephadex LH-20 column chromatography were used successively after the centrifuged supernatant was adjusted to pH 4.0. To identify the purity of the inhibitor, octadecylsilyl(ODS) HPLC was carried out with 5% methanol as a mobile phase. Finally, the purification yield of a tyrosinase inhibitor was 5.24%. The inhibitor was very soluble in water, methanol and ethanol but insoluble in acetone, butanol, ethylacetate and chloroform. The lambda(max) value of this inhibitor in water was 194 nm under UV light. The biochemical test of the inhibitor was positive in Molish, Benedict, cone. H2SO4, and KMnO4 tests but negative in iodine, ninhydrin, Million, Sakaguchi, xanthoproteic and Emerson tests. The tyrosinase inhibitor was stable against heat treatment of 100 degrees C for 50 minutes and pH 4 similar to 9. The IC50 value of this inhibitor was 19.2 mu g/ml for mushroom tyrosinase. In 1,000 mu g/ml inhibitor concentration, inhibition zone was 27 mm for Streptomyces bikiniensis NRRL B-1049. The inhibition of F-97 against mushroom tyrosinase was competitive with tyrosine.open
Dermabacter vaginalis sp. nov., isolated from human vaginal fluid
No full textA novel actinobacterial strain, AD1-86T, was isolated from the vaginal fluid of a Korean female and was characterized by a polyphasic approach. The strain was a facultatively anaerobic, Gram-stain-positive, non-spore-forming, non-motile, catalase-positive and oxidase-negative short rod. Colonies were creamy white, of low convexity and 1-2 mm in diameter after growth on DSM 92 agar plates at 37 °C for 2 days. The most closely related strains were Dermabacter hominis DSM 7083T and Helcobacillus massiliensis 6401990T (98.3 and 96.3 % 16S rRNA gene sequence similarity, respectively). The isolate grew optimally at 37 °C and pH 7 in the presence of 0.5 % (w/v) NaCl. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the cell-wall hydrolysates contained ribose, galactose and glucose. The DNA G+C content was 62.6 mol% and the mean DNA-DNA relatedness value of the isolate to D. hominis DSM 7083T was 31.1 ± 3.0 % (reciprocal: 48.2 ± 5.3 %). The major cellular fatty acids (>10 %) were anteiso-C17: 0, anteiso-C15: 0 and iso-C16: 0, and the menaquinones were MK-9, MK-8 and MK-7. The polar lipid profile of strain AD1-86T consisted of diphosphatidylglycerol, phosphatidylglycerol, two aminolipids and a glycolipid. Data from this polyphasic study indicate that strain AD1-86T represents a novel species of the genus Dermabacter, for which the name Dermabacter vaginalis sp. nov. is proposed; the type strain is AD1-86T (=KCTC 39585T=DSM 100050T).open
Production and characteristics of Hongkuk-ju using Monascus anka
No full textTo reproduce the brewing process of Hongkuk-ju and to identify the functional properties of it, Hongkuk-ju was brewed
using different additions of Hongkuk (100%, 90%, 70%, 50%) and Nuruk (0%, 10%, 30%, 50%). The quality elements,
including pH, total acidity, reducing sugar content, alcohol content and pigments (yellow, red, monacolin K and citrinin),
were measured. The pH values of Hongkuk-ju showed a slight difference (pH 4.08～4.58) right after the 1st stage mash;
further, the pH on all groups (H1, H2, H3 and H4) in the terminal of the 2nd stage mash (9 days in fermentation) were
similar, ranging approximately at pH 3.70. The total acidity change did not show a difference directly the 1st stage mash
(nearby 0.2 %); however, it began to show a slight difference at the terminal of the 2nd stage mash between the range
of 0.69～0.76%. The residual reducing sugar of the content was decreased with the increased Nuruk content. The alcohol
concentrations of the treatment brew with Nuruk ranging from 12.3% to 13.7% were higher than Hongkuk on its own. The
yellow and red pigment contents of Hongkuk-ju ranged from 7.2～8.8 O.D. units (yellow pigment) and from 4.4～5.1 O.D.
units (red pigment). The production of monacolin K and citrinin was the highest (9.48 ㎎/㎏ and 10.14 ㎎/㎏) when the
treatment solely brewed Hongkuk. The concentration of Nuruk and the preparation of the seed mash from it were critical
factors compared to the treatment of rice in brewing Hongkuk-ju.open
Sinirhodobacter hankyongi sp. nov., a novel denitrifying bacterium isolated from sludge
No full textA novel Gram-reaction-negative, facultative-aerobic, motile, non-spore-forming, oval-shaped and denitrifying bacterium, designated BO-81T, was isolated from sludge sampled in the Republic of Korea. This bacterium was investigated via a polyphasic approach to reveal its taxonomic position. The results of phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain BO-81T belonged to the family Rhodobacteraceae and was related to the closest species Sinirhodobacter ferrireducens (98.8？% sequence similarity), 'Sinorhodobacter hungdaonensis' (98.4 %), Rhodobacter lacus (97.8？%), Sinorhodobacter populi (96.8？%) and Rhodobacter maris (96.2？%). The average nucleotide identity and DNA-DNA hybridization values between strain BO-81T and its closely related strains were 77.7-94.2？% and 20.1-55.9？%, respectively, indicating that BO-81T represents a novel species of the genus Sinirhodobacter. Growth occurred at 18-40？°C on Reasoner's 2A medium in the presence of 0-7？%？NaCl (w/v) and at pH 6.0-9.0. Strain BO-81T was characterized chemotaxonomically as having ubiquinone 10 as its predominant respiratory quinone, summed feature 8 (C18？:？1 ω6c and/or C18？:？1 ω7c) as its major fatty acid and phosphatidylglycerol and phosphatidylethanolamine as its predominant polar lipids. The G+C content of the genomic DNA was 68.3？mol%. The results of physiological and biochemical tests allowed phenotypic differentiation of strain BO-81T from other Sinirhodobacter species with validly published names. Therefore, the isolate represented a novel species, for which the name Sinirhodobacter hankyongi sp. nov. (type strain BO-81T=KACC 19677T=LMG 30808T) is proposed.
Quality characteristics of cookies added with capsaicin powder
No full textThis study investigated the quality characteristics of cookies containing capsaicin, the main source of spicy taste in pepper,
which is well known for its various functions such as anti-oxidant, anti-cancer, anti-inflammatory, and anti-obesity activities,
as well as pain-relief effect. Cookie samples were made by adding the capsaicin powder at different levels, including 40
mg% (C1), 85 mg% (C2), and 150 mg% (C3). In this study, measurement of the moisture, pH, color, spread factor, hardness,
anti-oxidant activity, and sensory evaluation of the cookies was carried out. The results showed that the anti-oxidant activity
increased when more capsaicin powder was added to the cookies (p<0.001). The moisture also increased with increasing
capsaicin powder content (p<0.05), while the pH did not show any significant changes. As for the colors, the L value and
b value decreased as more capsaicin powder was added, while the a value increased. The spread factor also increased
significantly with the increase of capsaicin powder p<0.01). Although the hardness increased with capsaicin powder content,
no statistically significant differences were observed among the various cookies. In the sensory evaluation, Cookies
containing 40 mg of capsaicin obtained the highest score in color, while cookies containing 150 mg of capsaicin showed
the highest score in taste, texture, and overall acceptability.open
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