• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.106-110
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• 2008

This study was designed to evaluate the single dose toxicity and the protective effect of water extract of Cordyceps militaris grown upon Protaetia dreujtarsis (CMPD extract) on liver damage on carbon tetrachloride ($CCl_4$)- induced acute hepatotoxicity in Sprague-Dawley (SD) rats. The CMPD extract was once administered orally to both sexes of rats at dose of 2,000, 1,000 and 500 mg/kg body weight, the recommended maximum limit dose for acute toxicity. Neither significant toxic signs nor death was observed during the observation period. These results indicate that $LD_{50}$(lethal dose of 50%) of CMPD extract is greater than 2,000 mg/kg body weight in SD rats. To investigate also the effect of hepatoprotection of CMPD extract, SD rats were orally treated with CMPD extract (50, 25 and 12.5 mg/kg body weight) or silymarin (25 mg/kg body weight) before and after administration of $CCl_4$ (2 mL/kg body weight, 20% $CCl_4$ in olive oil). Treatment with CMPD extract or silymarin could decrease the GPT (glutamic-pyruvic transaminase) and GOT (glutamic-oxaloacetic transaminase) levels in serum when compared with $CCl_4$-treated group. Therefore, the results of this study show that CMPD extract can be proposed to protect the liver against $CCl_4$-induced hepatic damage in rats.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.274-283
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• 2020

This study focused on the in vitro investigation of antioxidant and anti-diabetic activities, along with neuroprotection against high glucose-induced cytotoxicity, in order to evaluate the physiological effects of Zanthoxylum piperitum and Zanthoxylum schinifolium. The highest total phenolic content was measured in the 40% ethanolic extracts of Zanthoxylum piperitum (EZP) and Zanthoxylum schinifolium (EZS). The in vitro EZP antioxidant activity showed a relatively higher ABTS/DPPH radical scavenging activity and malondialdehyde inhibitory effect than that of EZS. The EZP inhibited carbohydrate hydrolysis (α-glucosidase and α-amylase) more efficiently than EZS in anti-diabetic tests. However, EZS showed a more efficient inhibition of advanced glycation end-products formation than EZP. In addition, both EZP and EZS effectively protected human-derived neuronal cells from high glucose-induced cytotoxicity. Finally, the physiological compounds were analyzed using UPLC IMS-QTOF/MS^E, and the main EZP (quercetin-3-O-glucoside and 3-caffeoylquinic acid) and EZS (5-caffeoylquinic acid) compounds were identified as phenolic compounds.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.743-749
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• 2010

Objective of this research was to investigate the effect of various potassium concentrations in fertilizer solution on growth of and nutrient uptake by 'Chugyang' eggplant ($Solanum$ $melongena$ L.). Tissue analyses were conducted to determine the threshold levels of potassium in plants when disorders develop for potassium. The lower leaves of K deficient plants became spotted, yellowing in color, and finally necrosis occurred. The necrosis spread inward and upward. K toxic plants developed necrotic spot at the margin of old leaves and the surface of old leaves were twisted. The tissue K contents in the most recently fully expanded leaves and dry weight of full above ground plant tissue at 35 days after transplanting showed linear and quadratic response to elevated K concentrations with the equation of y=1.127+0.3147x ($R^2$=0.8916) and y=14.92+2.2743x-$0.1402x_2$ ($R^2$=0.8659). When 10% reduction in dry weight set to threshold levels, optimum tissue K contents are in the range from 2.1 to 5.1%. The yield through 150 days after transplanting and tissue K contents at 150 days after transplanting also showed quadratic and linear responses to elevated potassium concentrations in fertigation solution with the equation of y=153.24+345.5x-$18.46x^2$ ($R^2$=0.8620) and y=0.9921+0.3860x ($R^2$=0.9611), respectively. When the 10% reduction in yield is set to threshold levels, the tissue K contents for maximum yield should be around 3.4% to 5.9% in most recently fully expanded leaves.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.645-654
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• 2014

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP, $1.0{\mu}L{\cdot}L^{-1}$), a known ethylene action inhibitor, on fruit quality and incidence of physiological disorders during a simulated marketing period at $25^{\circ}C$ for 20 days in early-season Asian pear (Pyrus pyrifolia Nakai) 'Hanareum' that had been treated with 0, 0.5, 1.2 or 2.4% $GA_{4+7}$. Weight loss of stored fruits increased with $GA_{4+7}$ concentration, and the 1-MCP treatment slightly reduced the weight loss rates during the marketing period. Flesh firmness decreased abruptly in all 1-MCP-untreated fruits as the storage period extended to 10 d, whereas the firmness of 1-MCP-treated fruits remained high (> 30 N) during 15 days shelf-life. The effect of 1-MCP was significantly reduced when fruits were subjected to increased GA concentration. Higher soluble solids content and acidity during extended shelf-life were also apparent in 1-MCP-treated 'Hanareum' pears. The L-values (lightness) and hue angles of 1-MCP treated samples were higher than those of controls during 20 days shelf-life, but the a-value (redness) was lower in 1-MCP treated fruits. 1-MCP treatment did not decrease the level of ethylene evolution regardless of $GA_{4+7}$ concentration during shelf-life in early-season Asian pear 'Hanareum'. By contrast, 1-MCP treatment decreased the respiration rate significantly during shelf-life. The efficacy of 1-MCP was greatest in the GA-untreated fruit and was reduced as the $GA_{4+7}$ concentration increased. 1-MCP treatment influenced the severity of physiological disorders including core browning and mealiness: 1-MCP treatment completely blocked the incidence of core browning of during 15 days shelf-life, and reduced the severity of mealiness during 20 days shelf-life regardless of $GA_{4+7}$ concentration. Based on our results, we conclude that the use of $1{\mu}L{\cdot}L^{-1}$ 1-MCP can be of great benefit for maintaining quality and preventing physiological disorders in early-season pear cultivar 'Hanareum' pear, whereas its efficacy decreases with the concentration of $GA_{4+7}$ whereas its efficacy gradually decreases when the concentration of $GA_{4+7}$ paste increased.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.577-583
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• 2014

Benzyladenine (BA, 99% purity), MaxCel$^{(R)}$ (1.9% BA), Fruitone (3.5% NAA), MaxCel$^{(R)}$ + Fruitone, a nd s imazine were applied postbloom as fruitlet thinning agents to mature 'Hongro' and 'Fuji' apple (Malus domestica Borkh.) trees. BA and MaxCel$^{(R)}$ were applied at $100mg{\cdot}L^{-1}$ a.i. while Fruitone at $0.1mg{\cdot}L^{-1}$ a.i. and simazine at $400mg{\cdot}L^{-1}$ a.i. All PGRs were applied at 8 days after full bloom (DAFB, 6 mm fruit diameter) in both cultivars, while simazine was treated twice at 7 and 14 DAFB. In 'Hongro', the number of total fruit set per flower cluster in terminal buds was 1.67, 1.84, and 1.81 in MaxCel$^{(R)}$ + F ruitone, MaxCel$^{(R)}$, and simazine applications, respectively, when compared with 2.35 of water control. These reductions in fruit set were mainly attributed to the increased ratio of defruited clusters by the thinning agents. In 'Fuji' apple, the number of total fruit set per flower cluster in terminal buds was 1.29, 1.60, and 1.76 in MaxCel$^{(R)}$ + Fruitone, Fruitone, and MaxCel$^{(R)}$, respectively, when compared with 2.56 of water control in 'Fuji' apple. The addition of Fruitone to the MaxCel$^{(R)}$ promoted the thinning efficacy in both cultivars, compared to MaxCel$^{(R)}$ only. The thinning efficacies were similarly observed with lateral flowers in both cultivars. A significant increase of fruit weight by the postbloom thinning treatments was observed only in the BA application in 'Hongro', while the effect was observed in BA and MaxCel$^{(R)}$ in 'Fuji'. While the soluble solids content increased in the BA, MaxCel$^{(R)}$ and MaxCel$^{(R)}$+Fruitone treatments in both cultivars, other fruit quality attributes were not affected by the application of post-bloom thinning agents.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.162-169
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• 2010

The compulsory beef labelling system has launched from January 1st 2007 by the amended Food Hygiene Law, we were checked the actual conditions of beef origin with a nationwide scale by the Hanwoo differentiation specific test method which was developed by Korea FDA using 90 SNP biomarkers. The test method is useful tool to differentiate the beef origin carrying out the mission of KFDA's annual food safety management guidance. Also we have technically transferred the Hanwoo differentiation specific test method to other institutes as well regional KFDA and established the training program as a regular course in Korea Human Resource Development Institute for Health and Welfare. The beef used in this study were collected according to the 2009 Food safety guidance in roast beef restaurants where business site area greater than 100 $m^2$. Total 216 samples were consisted of 48 samples of the Seoul area and 168 of the region. The monitoring result from restaurants in all the region of Korea showed that 3 of 216 Hanwoo-labelled beefs were found out as a non-Hanwoo (1.3%). This results are gradually deceasing trend compared with 34.0% in 2005, 30.1% in 2006, 3.2% in 2007 and 5.14% in 2008. From these data, the Hanwoo differentiation specific test method on the settlement of the compulsory beef labelling system has an important role. As a outcome of this project, we might be considered the early settlement of the compulsory beef labelling system, technically transferred to other institutes and the establishment of regular training program of the test method.

• Korean journal of food and cookery science
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• v.17 no.4
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• pp.344-352
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• 2001

The purpose or this study was to investigate the effect or H $_2$O fraction or Dioscorea japonica Thunb(DJT) and selenium(Se) on the lipid peroxidation in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats weighing 180∼220g were divided into 5 groups: One normal rat group and 4 diabetic rat groups(the STZ-Control group, the DJT group, the DJT-Se group and the Se group). Diabetes was induced in the male rats by injection of STZ into tail vein at a dose of 45 mg/kg. The H$_2$O-fraction of DJT(500 mg/kg) was administered orally for 14 days. The supplementation was achieved with the AIN-76 recommendation diet by adding 2 mg/kg diet of selenium as Na$_2$SeO$_3$ which was prepared freshly everyday. The levels of glycogen in liver and muscle and protein in kidney, liver and muscle were measured. The liver concentrations of cholesterol and triglyceride were analyzed. Also, the malondialdehyde(MDA) levels in kidney, liver and lung were determined. The glycogen levels of liver and muscle in diabetic groups were not significantly different from the normal group. The protein concentrations of kidney, liver and muscle were not significantly different either, but the level of muscle protein was higher than STZ-Control group. The levels of liver cholesterol were significantly different between normal and STZ-Control groups and decreased in all diabetic experimental groups fed on H$_2$O-fraction of DJT and Se supplementation compared with the STZ-Control group. The levels of liver triglyceride were higher in the DJT-Se group than the STZ-Control group. The concentrations of MDA in lung decreased greatly by the administration of Se among all and the concentration of liver MDA was significantly reduced and that of DJT-Se group was the lowest. In conclusion, the results indicated that the administration of H$_2$O-fraction of DJT with selenium supplementation has a synergistic antioxidative effect by influencing on lipid metabolites and peroxidation especially in liver.

• Korean journal of food and cookery science
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• v.18 no.1
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• pp.43-50
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• 2002

This study was carried out to evaluate the quality attributes of frozen soy yogurts prepared by freezine soy yogurts, which are made of different types of Bifidobacteria (B. bifidum, B.breve, B. infantis) and oligosaccharides (fructooligosaccharides, galactooligosaccharides, isomaltooligosaccharides) containing $\alpha$-chymotrypsin treated soy protein isolate were evaluated in terms of overrun, melt-down quality, changes in the total number of Bifidobacteria after freezing, and sensory evaluation. The quality attributes of soy yogurts were also evaluated in terms of changes in the number of viable cells of Bifidobacteria in soy yogurts after incubation at 37$\^{C}$, pH 3.0 for 90 min, water holding capacity, and viscosity. The overrun of frozen soy yogurts fermented by B. bifidum showed the hiehest value but those fermented by B. infantis showed the lowest, while the melt-down quality of soy yogurts were vice versa. The total numbers of Bifidobacteria after freezing for 30 min in ice cream maker showed more than 10$\^$9/ CFU/ml. In sensory evaluation, all $\alpha$-chymotrypsin treated frozen soy yogsurt showed little beany flavor. In sour, sweet, and bitter tastes and mouth feel, the frozen soy yogurts fermented by B. bifidum evaluated better but those fermented by B. infantis evaluated worse. Also in the overall quality, the frozen soy yogurts fermented by B. bifidum were evaluated desirable but those fermented by B. infantis were evaluated undesirable. The water holding capacity and viscosity of soy yogurts fermented by B. bifidum showed the highest values but those fermented by B. infantis showed the lowest values. The total numbers of Bifidobacteria of all soy yogurts decreased from 10$\^$9/ CFU/ml to 10$\^$8/ CFU/ml after incubation at 37$\^{C}$, pH 3.0 for 90 min.

• Journal of Life Science
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• v.16 no.6
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• pp.1052-1059
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• 2006

The heat shock response is induced by environmental stress, pathophysiological state and non-stress conditions and wide spread from bacteria to human. Although translations of most proteins are stopped under a heat shock response, heat shock proteins (HSPs) are produced to protect cell from stress. When heat shock response is induced, conformation of HSF1 was changed from monomer to trimer and HSF1 specifically binds to DNA, which was called a heat shock element(HSE) within the promoter of the heat shock genes. Human HSF1(hHSFl) contains five cysteine(Cys) residues. A thiol group(R-SH) of Cys is a strong nucleophile, the most readily oxidized and nitrosylated in amino acid chain. This consideration suggests that Cys residues may regulate the change of conformation and the activity of hHSF1 through a redox-dependent thiol/disulfide exchange reaction. We want to construct role of five Cys residues of hHSF by redox reagents. According to two studies, Cys residues are related to trimer formation of hHSF1. In this study, we want to demonstrate the correlation between structural change and DNA-binding activity of HSF1 through forming disulfide bond and trimerization. In this results, we could deduce that DNA binding activity of DNA binding domain wasn't affected by redox for always expose outside to easily bind to DNA. DNA binding activity of wild-type HSF's DNA binding domain was affected by conformational change, as conformational structure change (trimerization) caused DNA binding domain.

• Journal of Life Science
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• v.16 no.6
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• pp.904-910
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• 2006

Dendritic cells (DCs) are the only antigen presenting cells (APCs) capable of initiating immune responses, which is crucial for priming the specific cytotoxic T lymphocyte (CTL) response and tumor immunity. Upon activation by DCs, CD4+ helper T cells can cross-prime CD8+ CTLs via IL-12. However, recently activated DCs were described to prime in vitro strong T helper cell type 1 $(Th_1)$ responses, whereas at later time points, they preferentially prime $Th_2$ cells. Therfore, we examined in this study the optimum kinetic state of DCs activation impacted on in vivo priming of tumor-specific CTLs by using ovalbumin (OVA) tumor antigen model. Bone-marrow-derived DCs showed an appropriate expression of surface MHC and costimulatory molecules after 6 or 7-day differentiation. The 6-day differentiated DCs pulsed with OVA antigen for 8 h (8-h DC) and followed by restimulation with LPS for 24 h maintained high interleukin (IL)-12 production potential, accompanying the decreased level in their secretion by delayed re-exposure time to LPS. Furthermore, immunization with 8-h DC induced higher intracellular $interferon(IFN)-{\gamma}+/CD8+T$ cells and elicited more powerful cytotoxicity of splenocytes to EG7 cells, a clone of EL4 cells transfected with an OVA cDNA, than immunization with 24-h DC. In the animal study for the evaluation of therapeutic or protective antitumor immunity, immunization with 8-h DC induced an effective antitumor immunity against tumor of EG7 cells and completely protected mice from tumor formation and prolonged survival, respectively. The most commonly used and clinically applied DC-based vaccine is based on in vitro antigen loading for 24 h. However, our data indicated that antigen stimulation over 8 h decreased antitumor immunity with functional exhaustion of DCs, and that the 8-h DC would be an optimum activation state impacted on in vivo priming of tumor-specific CTLs and subsequently lead to induction of strong antitumor immunity.