• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.562-567
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• 2008

The primary objective of this study was to select a probiotic starter for cheonggukjang using 60 strains isolated from rice straw. Among isolated strains, only 8 strains including strain B-59 evidenced proteolytic, amylolytic and soybean activity. These 8 strains were all gram-positive, spore-forming rods. The B-59 strain evidenced antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Pseudomonas fluorescens, and Vibrio parahaemolyticus. The antimicrobial activity of isolated B-59 was verified by its ability to inhibit the growth of S. aureus, L. monocytogenes, P. fluorescens, and V. parahaemolyticus. The selected B-59 strain was indentified as Bacillus licheniformis, as shown by a result of 99.0% homology upon API kit analysis. The selected B-59 strain also displayed viability in pH 2.5 artificial gastric juice, artificial bile acid, NaCl (2, 4, 8, 16, 32%), and ethanol (4, 8, 16, 32%). The antioxidative activity of the strain B-59 culture was assessed via a DPPH free radical scavenging activity assay. The activity increased with an increasing in the fermentation time of strain B-59 for 20 hours.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.542-547
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• 1998

Polyamine type polymer flocculants were synthesized and their characterization, viscosity and flocculation studies were conducted. In order to increase the molecular weight of polyamine flocculant which was prepared by polycondensation reaction from dimethylamine and epichlorohydrin, a small amount of 1,6-hexanediamine was employed. The incorporation of 1,6-hexanediamine up to 5.5 mole % replacing corresponding part of dimethylamine gave a branched type polyamine sample with increased intrinsic viscosity ([${\eta}$]=0.46 in 1 wt % aqueous NaCl solution). The amount of 1,6-hexanediamine above 5.5 mole %, however, resulted in gelation during polymerization. Utilizing raw water from Maegok potable water treatment plant, it was found that the addition of polyamine flocculant at a concentration of 1 mg/L level could reduce the amount of polyaluminum chloride (PAC) inorganic flocculant by half (15 mg/L). It was also observed that the incoporation of polyamine flocculant at 1 mg/L level was effective in the higher pH raw water, while PAC inorganic flocculating agent alone was not effective.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.464-472
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• 1996

The mechanism of thin-film formation by Ionized Cluster Beam Deposition(ICBD) was investigated. A simulation program based on the Monte-Carlo method was developed in order to investigate the effects of the acceleration voltage, substrate temperature, activation energy for the surface migration, and critical nuclei size on grain size and surface roughness. Studies of the effect of kinetic energy of clusters on the film formation processes revealed that high acceleration voltage enhanced the surface-migration of adatoms and made it easier for an epitaxial film to be formed. The relaxation time of kinetic energy of adatoms increased with the substrate temperature, which in turn increased the grain size of the crystalline film. This effect was more clearly distinguished when the critical nuclei size was large. The surface-migration activation energy was found to affect the interaction between the adatoms and the substrate and thus the relaxation time of kinetic energy. Investigations of the surface roughness revealed that the acceleration voltage, the substrate temperature, and the surface-migration activation energy exerted a collective effect on the morphology of the film surface.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.45-51
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• 2007

The Collected 70 samples from 5 sandwich shops were analysed for the pathogenic bacteria such as Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus. As a result of Listeria monocytogenes and Saphylococcus aureus were detected in 1 sample, 11 samples, respectively. However, Escherichia coli O157:H7 and Salmonella spp. were not detected in anywhere. The antibiotics test of isolated bacteria was pelformed by the disk diffusion method from NCCLS. The resistance rate of Listeria monocytogenes isolates was confirmed 38.5% to 10 species such as Am, B, P, and Va for antibiotics of 26 species. MRSA was determinated 4 strains in S. aureus isolates. The resistance pattern of Staphylococcus aureus isolates were confirmed 36.4% to P Am OX B K E CXM, 18.2% to P Am B K E CXM B, 9.1% to P Am B K, 27.3% to P Am B, and 9.1% to Te B Nb. Therefore, continuous surveillance and monitoring for antibiotic resistance strains are demanded for prevention of increases in multiple antibiotic resistance strains.

• Journal of Dairy Science and Biotechnology
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• v.34 no.4
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• pp.231-237
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• 2016

Kefir is a probiotic food. Probiotics have shown to be beneficial to health, and are currently of great interest to the food industry. Hence, this study was carried out to evaluate the lactase activity of kefir-isolated lactic acid bacteria. Three strains, Lactobacillu kefiri DH5 isolated from the kefir grains and Bifidobacterium animalis subsp. Lactis and Bifidobacteria longum 720, commercial probiotic LAB, were fermented in 10% reconstituted nonfat dry milk suspensions and incubated at $37^{\circ}C$ for 48 h, and then analyzed for various saccarides by HPLC. The results showed that changes in the concentrations of lactose and galactose were significantly decreased and increased, respectively (p<0.05), but all 3 probiotic strains tested in this study showed no increase in glucose concentration during 48 h of incubation. Both DH5 and BL720 showed high lactase activities (p<0.05), whereas BLC exhibited the lowest activity. Additionally, all three lactic acid bacteria showed high tagatose, but did not show high xylose and sedoheptulose. Finally, DH5, a kefir-isolated LAB, may have similar characteristics and properties to typical Bifidobacterium spp. and showed higher lactase activity than commercial Bifidobacterium spp.

• Korean Journal of Food Science and Technology
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• v.15 no.3
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• pp.231-237
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• 1983

In order to develop the commercial storage method of chestnut by irradiation combined with natural low temperature, a chestnut variety Ok-gwang was stored in a natural low temperature storage room ($450{\times}650{\times}250$ cmH; year-round temperature change, $2-17^{\circ}C$; R.H., 80-85%) on batch scale followed by irradiation with optimum dose level. Sprouting rate of chestnut was 100% after seven month storage in control whereas that of 20-25 Krad irradiated group was only 5-15%. In comparison of rotting rate, weight loss and texture, 25 Krad irradiated group was better than that of control. Moisture and reducing sugar were increased in contrast with the decrease of total sugar during nine month storage and these changes were more remarkable in control. Ascorbic acid content was slightly decreased both in control and irradiated group; more decrement was noticed in control.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.1-17
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• 1997

Tetracycline is known to be effective in eliminating periodontopathogens and have collagenolytic activity. This study was performed to observe the desorption kinetics and structural changes of tetracycline-treated barrier membranes for guided tissue regeneration. Four kinds of barrier membranes were tested : $Tefgen^{(R)}$(American Custom Medical, USA) and $Gore-Tex^{(R)}$(W.L. Gore & Associates Inc., USA) as nonresorbable membranes ; Resolut(polyglycolide & polylactide copolymer, W.L. Gore & Associates Inc., USA) and $Biomend^{(R)}$(collagen, Collatec Co., USA) as resorbable membranes. The membranes were cut into discs(diameter : 4mm) and were immersed in 5% tridodecylmethylammonium chloride(TIMAC) ethanol and air-dried. The membrane discs were absorbed with $100{\mu}g/ml tetracycline solution(pH8) for one minute and dried. For desorption kinetics, TC treated discs were immersed in phosphate buffered saline solution (PBS, pH 7.4). PBS was exchanged daily and TC concentration was measured by absorbance at 276nm on UV spectrophotometer. To measure remaining antibacterial activity, discs of 1 day to 4 weeks after desorption were placed on Mueller Hinton agar containing Bacillus cereus and incubated aerobically in $37^{\circ}C$ for twelve hours and the inhibition diameters were measured. To observe the structural change of membranes after TIMAC treatment or immersion in PBS, the membrane discs were examined under SEM. The results were as follows : 1. Total amounts of TC absorbed into membrane discs($0.7536mm^2$) were $2000{\mu}g$, $1800{\mu}g$, $2625{\mu}g$ and $2499{\mu}g$ for $Tefgen^{(R)}$, $Gore-Tex^{(R)}$, $Biomend^{(R)}$ and $Resolut^{(R)}$. 2. The concentration of TC released from barrier membrane discs was maintained over $4{\mu}g/ml$ until the fifth day in nonresorbable membranes and $Resolut^{(R)}$, but until the fourth day in $Biomend^{(R)}$, Until the ninth day in nonresorbable membranes and until the seventh day in resorbable membranes, the TC concentration was maintained over $1{mu}g/ml$. 3. The four membrane discs in the first day showed similar size of inhibition zone. One to four weeks later, the inhibition zone was much smaller in resorbable membrane discs than nonresorbable membrane discs. 4. Any structural change due to treatment of TIMAC was not observed on the nonresorbable membranes. $Resolut^{(R)}$ did not show any structural change except fibrillar loosening during immersion period, but Biomend showed destruction of membrane structure from the first week of immersion. This study indicates that tetracycline treated barrier membranes lead to the sustained release of tetracycline for over 7 days. This slow release pattern of tetracycline may contribute to the favorable clinical outcome of guided tissue regeneration.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.8-23
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• 1981

Color is one of the most important quality factors of red ginseng (Hong-sam) which is processed from fresh ginseng (Panax ginseng C. A. Meyer). Therefore, a study of characteristics of browning mixtures of aqueous fresh ginseng extracts, factors which accelerate the browning of the aqueous extracts, and the antioxidant activity of the browning mixtures may contribute to the improvement of the color and other quality of red ginseng and other ginseng products such as ginseng extracts. In the present study, factors which affect the Maillard-type browning reaction of aqueous extracts of fresh ginseng roots were investigated firstly by adding various concentrations (0.001-0.5M) of arginine or glucose solutions, by varying the browning reaction temperatures and durations. Secondly, some characteristics such as brown color intensity, amounts of water-soluble and ether-soluble extracts, amounts of non-dialyzable materials, pH, viscosity, and reactivity with 2,2'- diphenyl -1 - picrylhydrazyl and antioxidant activity of the browning mixtures of the aqueous fresh ginseng extracts with small amounts of 0.1 M arginine, 0.1 M glucose, and distilled water at various browning temperatures and reaction time were studied. The results of the present study are as follows. 1. Color intensity (absorbance at 470 nm) of the browning mixtures was increased by adding various concentrations of arginine solution to the fresh ginseng extract, but the addition of the same amount of glucose solution did not increase the color intensity. 2 The amounts of water- or ether-soluble extracts, amounts of non-dialyzable materials were slightly greater in case of the browning mixtures of the fresh ginseng extract with 0.1M arginine solution than in case of the browning mixtures of the fresh ginseng extract with the same amount of 0.1 M glucose solution. In the process of the browning reaction, the pH of the browning mixtures of the fresh ginseng extract with 0.1 M arginine solution decreased slightly, while that of the browning mixtures with 0. 1 M glucose solution was almost constant. 3. The color intensity (absorbance at 470 nm) of the browning mixtures of the fresh ginseng extract with 0.1 M arginine or 0.1 M glucose solutions did not correlate well with the reducing power or the antioxidant power of the browning mixtures. The antioxidant activity of 90% ethanol extracts from the earlier stages of the browning mixtures of the fresh ginseng extract with the arginine solution was almost comparable to that of the 90% ethanol extracts from the later stages of the corresponding browning mixtures. The browning mixtures of only the fresh ginseng extract or of the fresh ginseng extract with the glucose solution showed considerable antioxidant activity, although both showed less brown color intensity than the fresh ginseng extract with he arginine solution.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.267-283
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• 2011

Endangered species designated by The Ministry of Environment in region of Naejangsan National Park were found Lycoris chinensis var. sinuolata K.H.Tae & S.T.Ko, Iris koreana Nakai, Cymbidium macrorrhizum Lindl and Vexillabium yakushimensis (Yamam.) F.Maek.(4 taxa). The floristic special plants were recorded to a total of 159 taxa; that is, class I species (91 taxa) were containing as Chloranthus fortunei (A.Gray) Solms, Vicia anguste-pinnata Nakai and Euscaphis japonica (Thunb.) Kanitz, etc, class II species (17 taxa) were Pseudostellaria coreana (Nakai) Ohwi, Dryopteris expansa (C.Presl) Fraser-Jenkins et Jermy and Gymnocarpium dryopteris (L.) Newman, etc, class III species (32 taxa) were containing; Cirsium setidens (Dunn) Nakai, Parasenecio pseudotaimingasa (Nakai) B.U.Oh and Saussurea eriophylla Nakai, etc, class IV species (9 taxa) were Deutzia paniculata Nakai, Carex ligulata Nees and Thuja orientalis L., etc, and class V species (10 taxon) were Orobanche filicicola Nakai, Lycoris chinensis var. sinuolata K.H.Tae & S.T.Ko and Lycoris sanguinea var. koreana (Nakai) T.Koyama, etc. Endemic species of korea were identified 40 taxa such as Broussonetia kazinoki var. humilis Uyeki, Pseudostellaria coreana (Nakai) Ohwi and Silene seoulensis Nakai, etc. Plant species designated as Natural Monument were 2 species that Daphniphyllum macropodum forest(No. 91) and Torreya nucifera forest(No. 153) receive protection. The naturalized plants were identified 30 taxa; Fallopia dumetorum (L.) Holub, Persicaria orientalis (L.) Spach and Rumex crispus L., etc. Among them the ecosystem disturbance wild plants was not discovered.

• Korean journal of food and cookery science
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• v.33 no.2
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• pp.162-173
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• 2017

Purpose: The purpose of this study was to evaluate the folate contents and quality characteristics of commercial and fermented Kimchi and compare the correlation between folic acid and quality characteristics. Methods: The contents of total folate and quality characteristics were evaluated in 10 kinds of industrial and local Kimchi and nine kinds of other commonly consumed Kimchi. Changes in folate content and quality characteristics of Kimchi during 14 days of fermentation at $15^{\circ}C$ were compared. Results: Chungnam (L4) Kimchi had the lowest pH of 4.62, and acidity (0.57%) and salinity (3.26%) were highest compared to other areas. The content of total folate of D company (A) was the highest at $73.66{\mu}g/100g$. The content of total folate was significantly higher than those of Sesame leaf Kimchi (O9) and Young leafy radish Kimchi (O5) containing 65.77 and $62.82{\mu}g/100g$, respectively. The pH of fermented Kimchi decreased from 6.09 to 4.11 (p<0.05), and the acidity significantly increased (p<0.001) to 0.32-0.66%. Reducing sugar content decreased rapidly by 4 days and then slowly decreased (p<0.001). Total bacteria and lactic acid bacteria counts significantly increased (p<0.05) with fermentation period. Content of total folate was highest at $69.82{\mu}g/100g$ and $68.16{\mu}g/100g$ on days 0 and 2 of fermentation, after which it decreased to 77.6% at $15.61{\mu}g/100g$ on day 10 of fermentation. Conclusion: As a result, there was no definite trend regarding folate content in commercial Kimchi and other Kimchi. Young leafy radish, Chives, and Welsh onion Kimchi, which are rich in green leaves, are excellent folate source foods. The highest folate content of fermented Kimchi was identified on day 2 of fermentation. Therefore, it is recommended to use raw or immature Kimchi when using Kimchi as a folate source food.