• Elastomers and Composites
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• v.54 no.3
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• pp.241-246
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• 2019

Carbon master batch (CMB) rubber sheets, which are stored in stacks, are difficult to separate during reuse because of the adhesion between sheets caused by the stacked weight over time. To solve this problem, in the actual rubber product manufacturing process, various anti-tacking agents (solid powder or liquid surfactants) are applied to the sheet surface. In this study, the emulsion samples of zinc (Zn)-stearate/triethanolamine (TEA)-stearate mixtures were prepared using TEA-stearate as a surfactant, prepared using an industrially manufactured Zn-stearate powder, and their basic anti-tacking properties were studied. During the process of manufacturing emulsion, a heat treatment process and an auxiliary surfactant were introduced to improve the dispersion stability. Results showed that the heat-treated sample exhibited a significant improvement in terms of sedimentation, storage stability, and anti-tacking characteristics since the Zn-stearate particles were reduced to a smaller size by the heat-treatment than that of the original Zn-stearate powder.

• Journal of the Korean Society of Food Culture
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• v.22 no.2
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• pp.261-265
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• 2007

The antidepressant effects of Cirsium japonicum was revealed in previous studies using open field test and forced swimming test. The contents of total flavonoids and apigenin of Cirsium japonicum were analyzed and sensory evaluation of Cirsium japonicum tea was performed in order to develop Cirsium japonicum tea as an antidepressant. Among the different plant parts of Cirsium japonicum, leaves had the highest level of total flavonoids and apigenin contents and were followed by flowers and stems. Drying method affected total flavonoids and apigenin content of Cirsium japonicum, but regular pattern was not revealed. In sensory evaluation, overall acceptance of Cirsium japonicum flower-leaf mix tea was higher than those of Cirsium japonicum leaf tea. Also purchase intention of Cirsium japonicum flower-leaf mix tea was higher than those of Cirsium japonicum leaf tea.

• KSBB Journal
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• v.23 no.1
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• pp.96-100
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• 2008

In this work, we describes analysis of the antioxidant potential of Korean green tea phenolics using an high-performance liquid chromatography (HPLC) on-line $ABTS^{+}$ antioxidant screening method. In conjunction with the analysis of their 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) radical scavenging ability, the extraction of catechine compounds from Korean green tea were performed by various temperature and time. The optimum operating conditions were experimentally determined to analyze the catechine compounds in the pretreatment extracts. From the results, the extraction temperature $60^{\circ}C$, time 3 min was selected as an optimal antioxidant activity condition. The analysis by $C_{18}$ column was performed, the flow rate of mobile phase and UV wavelength was fixed at 1.0 ml/min and 254 nm, respectively. the mobile phase was composed from acetonitrile and water, and the gradient elution mode were applied.

• Natural Product Sciences
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• v.22 no.2
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• pp.87-92
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• 2016

Endothelial dysfunction in atherosclerosis is associated with increasing oxidative stress that could be reversed by antioxidant. Therefore epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC) and catechin (C) of tea flavonoids were investigated for their roles in regenerating endothelial cell. Peripheral blood mononuclear cells (PB-MNCs) were isolated, plated and cultured in medium with/without treatment of EGCG, ECG, EGC and C. Results showed that among all EGCG, ECG, EGC and C concentrations tested, $12.5{\mu}mol/L$ was not cytotoxic for peripheral blood-derived endothelial progenitor cells (PB-EPCs). Treatment of EGCG, ECG, EGC or C increased the percentages of CD34, CD133, VEGFR-2 expressions and suppressed hydrogen peroxide-induced percentages of reactive oxygen species (ROS) level in PB-EPCs. Taken together, our current results showed that EGCG, ECG, EGC or C of tea flavonoids could induce differentiation of PB-MNCs into PB-EPCs as well as protect PB-EPCs from oxidative damage by suppresing the intracellular ROS levels.

• Journal of environmental and Sanitary engineering
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• v.22 no.1 s.63
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• pp.37-47
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• 2007

In order to improve the Quality of fermented soybean Doenjang was investigated. The samples were prepared and fermented by the koji made with A. oryzae, B. subtilis and B. natto strains, that the product added green tea powder with sanitary canned food. 1. The water content of sample was 50.30-42.14%, pH value 6.03-5.52 and total acidity, 3.01-3.87. 2. The reducing sugar content for samples was 9.35-7.81%, Amino-N, 7.96-9.21%. 3. In the sensory evaluation test, the good sensory qualify that was S-2 sample than to S-1 and S-3. 4. The heavy metals analyzed from sample cans, tin, iron and lead content were 27.31-29.04 ppm, 5.32-5.91 ppm and trace amount.

• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.63-71
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• 2005

Panax ginseng leaves are produced as the by-product when Panax ginseng roots were harvested. The Panax ginseng leaves was examed for the applicable possibility as the functional food. In this study, the changes in chemical composition of Panax ginseng leaves was examed by three methods as the hot-air dried(DRT), the aged tea(AGT) and the heat processed tea(HPT). The general composition of Panax ginseng leaves tea was shown as similar results in 3 different process methods. The level of the crude lipid and reducing sugar concentration were decreased slightly in HPT. The free sugar content of DRT was higher than the HPT and AGT. The existence of the higher content of free sugar composition in order are sucrose, fructose and glucose. The concentration of serine was the highest in the free amino acids, which were shown from 309.6 mg% to 336.6 mg%. The contents of free amino acid in Panax ginseng leaves made by DRT was higher than by AGT and HPT. The concentration of Ca was shown as the highest content among the minerals and was 2,115 mg%. The contents of minerals were existed in order of Ca, K, Mg, P, Na, Mn, Fe, Zn and Cu. But there were hardly any remarkable differences of mineral concentrations of Panax ginseng leaves tea made by different processing methods. The concentration of water soluble solid of Panax ginseng leaves tea processed by HPT was higher than by DRT and AGT. The concentration of ascorbic acid was shown the highest value of 424.4mg% in HPT. There was no differences in the fatty acid composition according to their processing methods. The concentration of palmitic acid was higher than that of other fatty acid. The order of fatty acid concentration were palmitic aicd, linoleic acid, linolenic acid, oleic acid and stearic acid, abundantly. As a conclusion, HPT was shown as the best process method for the production of Panax ginseng leaves tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.105-109
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• 1987

The mineral content of Dolowe, which were prepared in the laboratory and marketed Korean products of Dolwoe, Japanese product of Dolwoe and Korean-roasted products of Dolwoe were analysed and compared. Dolwoe-leaf tea had high mineral content of Ca, Mg, Mn and Cu, while Dolwone-stem tea had high mineral content of K, Na and Fe. Especially in the ash of Dolwoe-stem tea showed the highest mineral content of K (33.4%) Dolwoe teas were extracted for 5 minutes as ratio of $1,000m{\ell}$ boiling water to 4g Dolwoe tea (250: 1, v/w). Comparing the ratio of extraction of minerals in Dolwoe tea made by us and marketed Dolwoe products, K was the most abundant element of all extractions with the rate of $83.2%{\sim}96.3%$ followed by Mg with $44.8%{\sim}62.2%$, Ca with $23.1%{\sim}64.4%$ and Na with $6.3%{\sim}55.6%$. On the other hand Mn, Fe and Cu were extracted in extremely small quantities.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.296-299
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• 1990

As an improved preparation method of Shikhae, a tea-bag system containing malt and amylolytic enzymes was developed in which extraction of malt enzymes and saccharification occured efficiently. The amylolytic activity of the malt was increased by adding the mixture of ${\alpha}-amylase$, glucoamylase and glucoisomerase. Malt and the mixture of enzymes were placed in tea-bag $(16{\times}20cm)$, extracted in water at $30-40^{\circ}C$ for 1-2 hours and followed by saccharification of the cooked rice at $60-70^{\circ}C$ for 3-4 hours. In the conventional Shikhae, content of maltose was about 50% and that of oligosaccharides larger than trisaccharides was about 40% of total sugar. The content of monosaccharides such as glucose and fructose was about 95% and this improved method would be effective for increasing the sweetness and the monosaccharide contents in the product.

• Natural Product Sciences
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• v.28 no.3
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• pp.121-129
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• 2022

Despite considerable efforts, cancer remains an aggressive killer worldwide. Chemotherapeutic drugs that are currently in use lead to destructive side effects and have not succeeded in fulfilling expectations. For centuries, medicinal plants are used for treating various diseases and are also known to have anticancer activity. The main aim of this research was to evaluate antiproliferative activity of saffron, clove, fenugreek, and green tea on Vero and MDA-MB-231 cell lines and to subsequently analyze the effect of these extracts on IRAK-4, TAK1, IKK-alpha, IKK-beta, NF-Kappa B, IRF3, IRF7 genes in Toll Like Receptors (TLRs) pathway. Antiproliferative assay was done by Neutral Red Dye uptake assay. Methanolic extract of green tea was found to be most effective against both cell lines as IC₅₀ was achieved at least concentration of the extract. For molecular studies, MDAMB-231 cells were sensitized with methanolic extract of green tea at same IC₅₀, and RT-PCR was performed to determine the relative expression of genes. Expression of IRAK-4, TAK1, IKK-beta, NF-Kappa B, IRF3 genes was down regulated and IRF7 and IKKalpha was upregulated. Green tea has a potential cytotoxic effect on both cell lines which was demonstrated by its effect on the expression of (TLRs) pathway genes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1108-1113
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• 2003

We performed this study to determine the effect of green tea on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of gammairradiation. The radioprotective effect of green tea was compared with the effect of diethyldithiocarbamate (DDC). Jejunal crypts were protected by pretreatment of green tea (p<0.01). Green tea administration before irradiation resulted in an increase of the formation of endogenous spleen colony (p<0.05). The frequency of radiation-induced apoptosis in intestinal crypt cells was also reduced by pretreatment of green tea (p<0.05). The radioprotective effect on jejunal crypts and apoptosis in the DDC treated group appeared similar to those in the green tea treated groups. Treatment with DDC showed no significant modifying effects on the formation of endogenous spleen colony. These results indicated that green tea might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the promotion nature of green tea and its components.