• Food Science of Animal Resources
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• v.33 no.1
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• pp.96-102
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• 2013

The possibility of instrumental differentiation of duck breast meat treated with different processing and storage conditions was investigated for industrial application. Duck breast meats, which were 1) refrigerated (fresh) after slaughter, 2) fresh but applied the torching process for the removal of remaining feathers (fresh-torched), and 3) frozen and thawed (frozen-thawed), were prepared and the torrymeter value and other quality factors were assessed. The torrymeter values of both duck breast meat and skin showed the lowest in frozen-thawed sample during the whole storage period. The drip loss of frozen-thawed sample was higher than those of fresh or fresh-torched ones. The number of total aerobic bacteria was lower in fresh-torched than fresh but both were not different from frozen-thawed at day 1 while no difference found thereafter. Sensory score of frozen-thawed sample was the lowest. The correlation analysis among the torrymeter value and quality factors of duck breast meat revealed that the torrymeter value is closely related with the total aerobic bacterial number, lipid oxidation, drip loss, and storage period but not with color. The results indicate that once the duck breast meat was frozen then thawed, drip loss and sensory quality can be affected and the torrymeter value can differentiate frozen-thawed from fresh and freshtorched duck breast meat.

• Journal of Life Science
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• v.20 no.12
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• pp.1777-1783
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• 2010

Plants generate reactive oxygen species (ROS) as a by-product of normal aerobic metabolism or when exposed to a variety of stress conditions, which can cause widespread damage to biological macromolecules. To protect themselves from oxidative stress, plant cells are equipped with a wide range of antioxidant proteins. However, the detailed reaction mechanisms of these are still unknown. Peroxiredoxins (Prxs) are ubiquitous thiol-containing antioxidants that reduce hydrogen peroxide with an N-terminal cysteine. The active-site cysteine of peroxiredoxins is selectively oxidized to cysteine sulfinic acid during catalysis, which leads to inactivation of peroxidase activity. This oxidation was thought to be irreversible. Recently identified small protein sulphiredoxin (Srx1), which is conserved in higher eukaryotes, reduces cysteine.sulphinic acid in yeast peroxiredoxin. Srx1 is highly induced by $H_2O_2$-treatment and the deletion of its gene causes decreased yeast tolerance to $H_2O_2$, which suggest its involvement in the metabolism of oxidants. Moreover, Srx1 is required for heat shock and oxidative stress induced functional, as well as conformational switch of yeast cytosolic peroxiredoxins. This change enhances protein stability and peroxidase activity, indicating that Srx1 plays a crucial role in peroxiredoxin stability and its regulation mechanism. Thus, the understanding of the molecular basis of Srx1 and its regulation is critical for revealing the mechanism of peroxiredoxin action. We postulate here that Srx1 is involved in dealing with oxidative stress via controlling peroxiredoxin recycling in Arabidopsis. This review article thus will be describing the functions of Prxs and Srx in Arabidopsis thaliana. There will be a special focus on the possible role of Srx1 in interacting with and reducing hyperoxidized Cys-sulphenic acid of Prxs.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.8
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• pp.852-859
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• 2006

The novel microbial process such as Anammox(anaerobic ammonium oxidation) and Canon(completely autotrophic nitrogen removal over nitrite) processes is promising biotechnology to remove nitrogen from ammonium-rich wastewater like anaerobic sludge digester liquid. In this research, a new Canon-type nitrogen removal process adopting upflow granular sludge bed type configuration was investigated on its feasibility and process performance, using synthetic wastewater and sludge digester liquids. Air as an oxygen source was provided in an external aeration chamber with flow recirculation. In the first experiment using the synthetic wastewater(up to 110 mg $NH_4$-N $L^{-1}$), the ammonium removal was about 95%(92% for T-N) at effective hydraulic retention time(HRT) for 3.8 days. In the second experiment using the sludge digester liquids($438{\pm}26$ mg $NH_4$-N $L^{-1}$), the total nitrogen removal was $94{\pm}1.7%$ at HRT for 5.4 days and $76{\pm}1.5%$ at HRT for 3.8 days, respectively. Little nitrite and nitrate were observed in the effluent of both experiments. The process revealed quite a lower oxygen($0.29{\sim}0.59$ g $O_2$ $g^{-1}N$) and less alkalinity($3.1{\sim}3.4$ g $CaCO_3$ $g^{-1}N$) consumption as compared to other new technology in microbial nitrogen removal. The process also offers the economical compact reactor configuration with excellent biomass retention, resulting in lower cost for investment and maintenance.

• Food Science and Preservation
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• v.16 no.2
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• pp.198-203
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• 2009

We examined the effects of electron-beam irradiation(0.5, 1, 2, or 5 kGy) on microbiological, physicochemical, and sensory quality characteristics of Myungran Jeotgal, Korean fermented seafood, during subsequent storage at $4^{\circ}C$ for 2 weeks. Viable counts of total aerobic bacteria, yeasts and molds, and total coliforms fell, after irradiation, to below detection limits($10^1CFU/g$). The pH of irradiated Myungran Jeotgal was maintained during storage but that of the non-irradiated control decreased. Sensory quality was not affected by electron-beam irradiation, except that color scores in samples irradiated with 2 and 5 kGy were lower than that of the control. Lipid oxidation tended to rise with increased irradiation dose and longer storage periods. The results suggest that electron-beam irradiation can be used to extend the shelf-life of Myungran Jeotgal without apparent quality attribute deterioration. However, means of preventing lipid oxidation resulting from electron-beam irradiation need consideration if irradiation is to find further applications in the food industry.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.685-694
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• 2010

The present study investigated the combined effects of modified atmosphere packaging (MAP) and organic acid salts on the quality and shelf-life of Hanwoo ground beef patties. The ground beef containing 500 ppm of ascorbic acid was prepared with air-packaging (Air-P), high oxygen-MAP (70% $O_2$+30% $CO_2$/OxyMAP), and nitrogen-MAP (100% $N_2$/NitroMAP), in combination with organic acid salts (1500 ppm of sodium acetate and 500 ppm of calcium lactate). The samples were stored for 11 d at $5^{\circ}C$. The pH value of ground beef patties decreased during storage in all the treatments. The ground beef patties with organic acid salts showed relatively higher level of pH during storage compared with non-added patties (p<0.05). Lipid oxidation was accelerated in OxyMAP while it was delayed in NitroMAP treated with organic acid salts. Nitro-MAP treated with organic acid salts was effective in stabilizing the color characteristics of lightness (CIE $L^*$) and redness (CIE $a^*$) during storage. Oxygen content in MAP was shown to be a more important factor affecting color stability and lipid oxidation of ground beef than organic acid salts. The aerobic and anaerobic bacterial counts were reduced both in OxyMAP and NitroMAP (p<0.05), and the lactic acid bacteria was inhibited by Oxy-MAP (p<0.05). Coliform bacteria decreased during storage as pH value was decreased in all treatments. According to the sensory evaluation, the ground beef patties in NitroMAP showed the best quality among all treatments during storage. Therefore, Hanwoo ground beef patties added with sodium acetate and calcium lactate and packed with NitroMAP showed better quality characteristics than other treatments. This packaging method is recommended and could be utilized for packaging hanwoo ground beef patties for improving quality and extending shelf-life.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.737-743
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• 2013

The aim of this research is to evaluate the effects of cooking time and storage temperature on the quality of home-made retort pouch packed Chuncheon Dakgalbi. The leg meat of broiler is being cut into cubes and is mixed with the Dakgalbi sauce and vegetables. Around 200 g of Chuncheon Dakgalbi is being stuffed into a retort pouch and then vacuumed. The retort pouch packed Chuncheon Dakgalbi is subjected to cooking (autoclaving) at $110^{\circ}C$ and 0.75 Kgf for 10, 20 or 30 min and then transferred to the chilling room at $2^{\circ}C$ for rapid cooling procedures. Subsequently, the samples are stored at $4^{\circ}C$ or $25^{\circ}C$ for 4 wk. According to results of sensory evaluation, the highest sensory scores were found in Chuncheon Dakgalbi which was cooked for 30 min (p<0.05). Prolonged cooking time tends to decrease the pH, CIE $L^*$ and CIE $a^*$ levels, and slightly promote the lipid oxidation and protein deterioration. The Chuncheon Dakgalbi being cooked for 10 min promoted the lipid oxidation and protein deterioration during storage at $25^{\circ}C$. Moreover, the total aerobic and anaerobic bacteria in Chuncheon Dakgalbi being cooked for 10 min started to grow after 3 wk of storage at $25^{\circ}C$. Cooking (autoclaving) at $110^{\circ}C$ for 30 min is able to maintain the quality and shelf-life of retort pouch packed Chuncheon Dakgalbion the market.

• Food Science of Animal Resources
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• v.42 no.5
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• pp.816-832
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• 2022

To evaluate the effects of early postmortem vacuum packaging (VP) on meat quality during postmortem chilled storage, hot-boned lamb was vacuum-packaged at 1, 6, 12, 24, and 48 h postmortem and stored around 2℃ until 168 h postmortem, with lamb packaged in plastic wrap as the control (aerobic packaging). Intramuscular pH decline was delayed when lamb was vacuum packaged at 1, 6, and 12 h postmortem (p<0.05). The lamb vacuum-packaged at 1 h postmortem (VP-1h group) had significantly lower shear force values and purge losses accompanied by lower free thiol group values than other treatments during postmortem storage and was also higher in extractable calpain-1 activity by 6 h postmortem (p<0.05). Free thiol group concentrations were significantly higher after VP at 6 and 12 h postmortem (p<0.05). Packaging lamb under vacuum very early postmortem produced the lowest shear force and purge loss, likely by slowing heat loss and muscle temperature decline, implying that lamb quality is improved by VP when applied very early postmortem. This was at the expense of protein oxidation, which was unrelated to other meat quality measurements, most likely because potential contracture during hot boning confounded its impact. Further research is required to understand the implications of the interaction between protein oxidation, VP, and hot boning on the acceptability of lamb.

• Journal of the Korean Applied Science and Technology
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• v.40 no.1
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• pp.1-12
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• 2023

It was investigated whether a combination of PPARα activator fenofibrate and swimming exercise (H/F/S) would have a beneficial synergistic effect on improving inflammation of white adipose tissue compared to the single prescription of fenofibrate (H/F) and swimming exercise (H/S) in male mice that fed high fat diet. The body weight, weight of white adipose tissue and total cholesterol levels in the serum increased in mice-fed high fat diets (H) compared to mice-fed low fat diets (L). Compared to H, both H/F and H/S decreased these. These levels reduced by fenofibrate were more effectively reduced by the combination of fenofibrate and swimming exercise (H/F/S). As a result of examining the expression of inflammatory cytokines genes and fatty acid oxidation genes in white adipose tissue, H increased compared to L, both H/F and H/S decreased compared to H, and H/F/S decreased further compared to H/F. Thus, this study revealed that the combination of fenofibrate and swimming exercise in male mice fed high-fat diet suppresses inflammation of white adipose tissue caused by obesity through promoted fatty acid oxidation more effectively than the fenofibrate alone, and suggested a practical way to improve inflammation of adipose tissue caused by obesity.

• Journal of Applied Biological Chemistry
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• v.57 no.4
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• pp.287-294
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• 2014

To improve the shelf life of low-salt Kochujang, Korean hot pepper paste, antimicrobial materials were added at different times before and after aging. The kochujang was then packaged and stored at $30^{\circ}C$ for 15 weeks, and changes in microbiological and physiochemical properties were evaluated. Hunter a- and b-values decreased considerably during storage. The total color difference (${\delta}E$) was greater in the ethanol-chitosan (EC) treatment than in the control and after pasteurization (A-P) treatment. Gas was produced until the seventh week of storage. The control and the A-P treatments produced more gas than the other treatments, and these had the largest number of yeasts and aerobic bacteria. The pH of the EC treatment was higher than that of the other treatments, and the A-P treatment had the highest level of titratable acidity. During storage, the oxidation-reduction potential was lower in the EC and ethanol-mustard-chitosan (EMC) treatments. The reducing sugar content decreased remarkably in the control and A-P treatments, with high production of ethanol. There was a significant change in the content of amino-type nitrogen in the control and A-P treatments, and the content of ammonia-type nitrogen was lowest in the EMC treatment. In the sensory test of kochujang, the ethanol-mustard (EM) and ethanol (E) treatments were significantly higher than the EC, control, and A-P treatments (p <0.05). EM or E alone was effective in extending the shelf life of kochujang when added before aging.

• Journal of Animal Environmental Science
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• v.6 no.3
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• pp.185-190
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• 2000

TAO system and solid-liquid separation (28mesh filter and 200mesh filter) were applied in processing piggery slurry to see the reduction of N and P and to draw the efficiency in reducing manure application area. The results are as follows; 1. The amount of N and P in slurry of $4.6m^3/day$ was 22.5kg/day ($4,893mg/{\ell}$) and 7.32kg/day ($1,592mg/{\ell}$). 2. Reduction rate of N and P by TAO reactor was 9.9 kg/day (46.0%) and 3.47kg/day(34.0%). 3. Reduction rate of N and P by Solid-liquid separation was 10.5kg/day (46.6%) and 5.12kg/day (69.8%). 4. One the basis of the amount of nitrogen composting, the square size of liquid manure sprinkled area was reduced from 74.6ha/y to 39.0ha/y in rice paddy, and from 63.2ha/y to 33.0ha/y by the treatment.