• Journal of Life Science
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• v.28 no.6
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• pp.656-662
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• 2018

Flavin-containing monooxygenases from Corynebacterium (cFMOs) were mutagenized based on homology modeling to develop variants with an enhanced indigoid production capability. The four mutants, F170Y, A210G, A210S, and T326S, which fused to a maltose-binding protein (MBP), were constructed, and their biochemical properties were characterized. Of these, purified MBP-T326S required a higher concentration of exogenous FAD (100 mM) than the wild-type MBP-cFMO for optimal activity and showed a 3.8-fold increase in the $k_{cat}/K_m$ value at $100{\mu}M$ FAD compared to that of MBP-cFMO at $2{\mu}M$ FAD. The indole oxygenase activities of MBP-T326S decreased to 63-77% compared to that of the MBP-cFMO In addition, MBP-T326S displayed a very low level of futile NADPH oxidase activities (21-24%) in the absence of a substrate. Mutant proteins except for T326S displayed similar $K_m$ and increased $k_{cat}/K_m$ values compared to the wild-type. MBP-F170Y and -A210S mutants showed elevated indole oxygenase activity higher than 3.1- and 2.9-fold, respectively, in comparison with MBP-cFMO. When indigoid production was carried out in LB broth with 2.5 g/l of tryptophan, Escherichia coli expressing cFMO produced 684 mg/l of indigo and 104 mg/l of indirubin, while cells harboring T326S produced 1,040 mg/l of indigo and 112 mg/l of indirubin. The results indicate that the production of indigo was 13% higher when compared to a previous report in which an E. coli expressing FMO from Methylophaga produced 920 mg/l of indigo. The protein engineering of cFMO based on homology modeling provided a more rational strategy for developing indigoid-producing strains.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.117-123
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• 2011

The purpose of this study was to evaluate and compare different elution and concentration methods for optimization of human rotavirus (HRV) detection method using real-time RT-PCR and cell culture techniques. The leafy vegetable samples (lettuce, Chinese cabbage) were artificially inoculated with HRV. Viruses were extracted from the vegetables by two different elution buffers, buffer A (100 mM Tris-HCl, 50 mM glycine, 3% beef extract, pH 9.5) and buffer B (250 mM Threonine, 300 mM NaCl, pH 9.5), and the extracted viruses were concentrated by filtration and PEG precipitation sequentially. To determine infectivity of the viruses, the viruses recovered from the samples were infected to the MA-104 cells, and integrated cell culture real-time RT-PCR was performed at 1, 48, 72, 96, 120, 144, 168 h post-infection (p.i.). The elution buffer A was more efficient in extracting the virus from the produce samples tested than the buffer B, 29.54% and 18.32% of recoveries, respectively. The sensitivity of real-time RT-PCR method was markedly improved when the virus was concentrated by the filtration method. When the viruses were eluted and concentrated by buffer A and filtration, respectively, the average recovery rate was approximately 51.89%. When the viruses recovered from samples were infected to MA-104 cell, infectious HRV was detected within 48 h p.i. by ICC/real-time RT-PCR, whereas cytopathic effects were not observed until 72 h p.i. The optimized detection method evaluated in this study could be useful for rapid and reliable detection of HRV in fresh produce products and applied for detection of other food-borne viruses.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.761-767
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• 2007

This study was conducted to determine the effects of exogenous zinc-metallothionein (Zn-MT) on anti-oxidative function and pork quality. After feeding a corn-soybean meal-based diet for two weeks, 48 pigs ($Duroc{\times}Landrace{\times}Chinese\;Black Pig$) were assigned randomly to four groups. Pigs in Group 1 were maintained under non-stress conditions, whereas pigs in Groups 2, 3 and 4 were aggressively handled for 25 min to produce stress. Pigs in Groups 1, 2, 3, and 4 received intramuscular administration of saline (control group; CON), 0 (negative control group; NCON), 0.8 (low dose group; LOW), and 1.6 (high dose group; HIGH) mg rabbit liver Zn-MT per kg body weight, respectively. Pigs were slaughtered at 3 and 6 h post-injection. Zn-MT treatment increased (p<0.05) the activities of superoxide dismutase (SOD) and glutathione-peroxidase (GSH-PX) while decreasing the concentration of malondialdehyde (MDA) in liver. These responses were greater (p<0.05) at 6 h than at 3 h post Zn-MT injection. Zn-MT treatment increased (p<0.05) hepatic SOD mRNA levels in a time and dose-dependent manner and decreased (p<0.05) serum glutamate-pyruvate transaminase and lactate dehydrogenase activities (indicators of tissue integrity). Zn-MT administration decreased (p<0.05) lactate concentration and increased (p<0.05) pH and water-holding capacity in the longissimus thorasis meat. Collectively, our results indicate that intramuscular administration of Zn-MT to pre-slaughter stressed pigs improved tissue anti-oxidative ability and meat quality.

• Journal of Nutrition and Health
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• v.50 no.6
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• pp.645-654
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• 2017

Purpose: The purpose of this study was to investigate the current status of dietary education carried out by dieticians or nutrition teachers at elementary, middle, and high schools in Gyeonggi province. We compared dietary education status not only among school level but also between dieticians and nutrition teachers. Methods: The survey using self-administered questionnaires was conducted by dieticians or nutrition teachers at 91 schools (43 elementary schools, 33 middle schools, and 15 high schools) in Gyeonggi province in December, 2015. The questionnaire consisted of questions regarding general characteristics of respondents, current status of dietary education, opinion about dietary education methods, and cooperation level of persons concerned. Results: The placement rate of nutrition teachers was 50.5% overall. Only 36 out of 91 schools conducted regular dietary education, and the percentage of schools conducting regular dietary education was significantly different according to school level with the lowest percentage in high schools, equivalent to 20% (p = 0.003). The average annual dietary education time was 12.4 hours, and it was very low in high schools (5.1 hours) and in schools without a nutrition teacher (1.6 hours). The levels of cooperation and support from principals, teachers, parents, and students were significantly lower in high schools than elementary and middle schools (all p < 0.001) and in schools without a nutrition teacher than schools with a nutrition teacher (all p < 0.05). Conclusion: The results show that the level of dietary education is not enough and needs to be improved, especially at middle and high schools and at schools without a nutrition teacher. Government support polices need to be implemented to encourage dietary educational activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1448-1453
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• 2012

Fried fish pastes containing different size and amounts of red ginseng powder (RGP) were manufactured, and their physico-chemical and biological properties, including color changes, preservation, weight loss after heating, lipid oxidation, and total colony count were analyzed to improve fish paste quality. Sensory evaluation of fish pastes containing RGP was carried out, and the results showed that 1% and 850 ${\mu}m$ sized RGP additives were most preferred. In the color change test, decreased $L^*$ (lightness), increased $a^*$ (redness), and increased $b^*$ (yellowness) values were observed, which was similar to other additive-containing commercial fish pastes. In the physical properties test, hardness and chewiness significantly increased in the 90 ${\mu}m$ sized RGP group. Weight loss of fish pastes containing RGP after heating was attenuated compared to commercial fish pastes. Fish paste containing RGP showed an inhibitory effect on lipid oxidation. Especially, the 10 ${\mu}m$ sized RGP group showed the most significant inhibitory effect on lipid oxidation and reduced total microbes during storage. Therefore, 1% addition of RGP can give rise to high quality fish pastes through improvement of sensory evaluation and physico-chemical properties. Moreover, functionally and physiologically improved fish pastes can be produced by adding different amounts of RGP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1639-1644
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• 2012

This study analyzed the Importance-Performance Analysis of selective attributes of Home Meal Replacement (HMR). This study was conducted using a primary field survey on department stores and wholesale markets in Seoul and Gyeonggi province. A total of 201 out of 234 questionnaires were analyzed. First, the highest intake frequency was 1~3 times a month (100 respondents: 48%), the most common purchasing place was wholesale market (148 respondents: 73.6%), and the most cited reason for preference was convenience (115 respondents: 57.2%). According to the IPA results, selective attributes with low satisfaction and high importance in the second quadrant were 'quality', 'health', 'hygiene', 'origin of food', and 'safety'. These results suggest that the microbiological and sensory qualities of HMR production should be improved to meet consumer's expectations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1510-1518
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• 2014

This study investigated the effects of calcium citrate on papain-induced osteoarthritis in C57BL/6J mice. Osteoarthritis was induced by injecting $6{\mu}L$ of papain into the knee joints of mice. Calcium citrate was made by crushing the centrifuged precipitate after reacting 0.5 M citric acid with 1 kg of oyster shell extract. The mice were divided into five groups (n=8). The normal group was untreated, whereas the papain group was induced to have osteoarthritis and treated with $200{\mu}L$ of water per day. The papain+DS group was treated with diclofenac sodium. The papain+calcium citrate groups were treated with calcium citrate at 150 and 300 mg/kg/bw for 28 days. Proteoglycan contents in articular cartilages were measured by safranin O/fast green staining and hematoxylin & eosin staining. Histopathological changes in cartilages were analyzed by the Rudolphi score approach. Contents of pro-inflammatory cytokines including TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 in plasma, were measured by the ELISA method. Body weights among the treated groups were not significantly different compared with that of the normal group. Cartilage loss and joint instability in the calcium citrate group improved significantly (P<0.05) in a dose-dependent manner compared with the papain group. Further, proteoglycan content of the calcium citrate group was considerably (P<0.05) higher than that of the papain group. Osteoarthritis scores in the calcium citrate group were considerably (P<0.05) reduced compared with the papain group. In the group treated with calcium citrate, contents of TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 in plasma were significantly (P<0.05) reduced in a dose-dependent manner in comparison with the normal group. Based on these results, we suggest that calcium citrate is effective for treatment of osteoarthritis.

• Korean Journal of Poultry Science
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• v.32 no.2
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• pp.89-96
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• 2005

This studies were conducted to investigated the feeding effects of extruded broiler manure(BMERF) mixture and swine manure(SFERF) mixture on laying performance and egg qualify of laying hens. As a experimental feed, broiler manure, corn and tapioca were mixed in 50, 30 and $20\%$ to use for treated extrusion feed(BMERF, Exp. 1) and food waste(FW), swine manure and com were also mixed in 40, 40 and $20\%$ to use it(SFERF, Exp. 2) and implemented during 12 weeks, four replication and 30 chick of each treatment. The nutritional ingredients(protein, energy and calcium contents) of food waste, broiler manure and swine manure had been significantly improved(p<0.05) when handling extrusion. In the Exp. 1, the feed intake was much higher BMERF $40\%$ and BMERF $20\%$ than control and BMERF $10\%(p<0.05)$, the egg production of control, BMERF $10\%$ and BMERF $20\%$ were not significantly difference(p>0.05), but BMERF $40\%$ was significantly lower(p<0.05). The feed efficiency of control and BMERF $10\%$ were not significantly difference(p>0.05), but BMERF $20\%$ and BMERF $40\%$ were significantly lower(p<0.05). York color, White height and Haugh unit did not affected by BMERF additive. In the Exp. 2, the feed intake of control, FW $20\%$, SFERF $10\%$ and SFERF $20\%$ were not significantly difference(p<0.05), but FW $40\%$ and SFERF $40\%$ were significantly higher(p<0.05). The egg production of SFERF $10\%$ and SFERF $20\%$ were not significantly difference(p>0.05) with control, but FW $20\%$, FW $40\%$ and SFERF $40\%$ were significantly lower(p<0.05). The feed efficiency was similar tendency to the egg production, however, the egg weight, york color, white height and haugh unit were not significantly difference among each treatments(p>0.05).

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.361-370
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• 2010

This study was carried out to establish the analytical method of MCPA residue in brown rice and rice straw by HPLC/UVD. When MCPA was extracted from sample under the pH 3.6 by adding acetone 200 mL and 1N-HCl 100 mL, the extraction efficiency was high by 87%. And purification efficiency was high by 83% when 5 mL of 1% methanol/acetonitrile was eluated by the florisil Sep-pak cartridge column. From spiking of $0.1{\mu}g\;mL^{-1}$ and $0.25{\mu}g\;mL^{-1}$ of MCPA to control sample, respectively, average recovery rate of MCPA in brown rice was 96.0% and 94.9% and that in rice straw was 92.5% and 88.2%, respectively. Precision of experiment was very high by relative standard deviation of 1.5% to 5.7%. In brown rice and rice straw treated with bentazone+MCPA (11+1.2%) of 30 kg and 60 kg per ha at 30 days after rice transplanting, respectively, maximum residue limit was under $0.05{\mu}g\;mL^{-1}$ of the recommended rate of Korean Food and Drug Administration. From the above results, the analytical procedure of MCPA in plants such as hydrolysis, saponification and derivatization were ommited, and retention time was faster and recovery rate was higher than the existed results of HPLC/UVD. Therefore, these results were greatly improved and seemed to be usefully applied for residue analysis of MCPA in plants.

• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.570-577
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• 2000

Korean duok has a many kinds of shape and cooking preparation and they were improved variably Also they were famous for special festival food and theirs demand are becoming popular. Since theirs retrogradation are degraded its taste and texture during the storage which should be resolved in most food industry. There is a possibility that storage temperaure and additives may involve in retrogradation. Recently Shon et al. reported that some sugar alcohols was effective for reducing it. We can search a kinds of additives, trehalose which can protect from shocks by freezing or heating. Furthermore they emphasized the trehalose can act as substitute for bound water in dehydration situation, and trehalose more effective than oligosaccharide or sugar alcohol. Therefore we tried to exam the changes of many characteristics of glutinous and rice duck with 2 levels trehalose in the storage.