• Food Quality and Culture
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• v.2 no.2
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• pp.89-96
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• 2008

In order to determine whether green tea tannin ameliorates abnormal arginine metabolism as the result of excessive arginine, we have assessed the effects of the administration of green tea tannin mixture in rats treated 30 days with 2% arginine. In the arginine-treated group, the level of guanidino compounds such as arginine (Arg), guanidinoacetic acid (GAA), creatinine (Cr), methylguanidine (MG) and guanidinosuccinic acid (GSA), nitric oxide, urea, protein and glucose increased significantly in the serum, urine and kidney, whereas the oxygen species-scavenging enzymes of kidney were reduced as compared with the non-arginine-treated group. By way of contrast, the administration of green tea tannin reduced blood urea nitrogen and serum creatinine, and reduced the urinary excretion of guanidinoacetic acid, creatinine, and $NO_2^-+NO_3^-$. The increased levels of urinary urea, protein and glucose in the arginine-treated group were also lowered by the administration of green tea tannin. In these groups, the activities of superoxide dismutase and catalase in the kidney were increased, thereby suggesting the involvement of radicals in the normalizing of kidney function. These results show that the abnormal renal function induced by the adminstration of excessive arginine in rats may be restored by treatment with green tea tannin.

• Journal of Applied Biological Chemistry
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• v.53 no.2
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• pp.116-119
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• 2010

A Maengjong-juk (Phyllostachys pubescence) leaves tea was prepared by using a series of drying/roasting and rolling processes. The produced tea contained abundant dietary fibers (60.42%), $\beta$-carotenes (7.9 mg RE%), and calcium (437.1 mg%). Also the polyphenol content ($155.33\;{\mu}g/g$-tea) and DPPH free radical scavenging activity ($IC_{50}=212\;{\mu}g/mL$) of Maengjong-juk leaves tea were greatly higher than those of simply dried leaves. These results imply that the tea preparation is effective to utilize the useful components of Maengjong-juk leaves.

• Journal of Nutrition and Health
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• v.33 no.7
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• pp.733-738
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• 2000

The purpose of this study was to investigate the effects of green tea on gene expression of superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) in rat liver exposed to microwave. Sprague-Dawley male rats with 200$\pm$10g body weight were assigned to normal and microwave exposed groups : microwave exposed groups ; microwave exposed groups were divided two groups : microwave(MW) group which was administrated the distilled water and green tea(GT) group which was administrated the green tea extracts. The rats were irradiated with microwave at frequence of 2.45 GHz for 15 min and then the gene expression in the damaged tissue were investigated at 0.1, 3, 4,6 and 8 days after the microwave irradition to compared with the normal group. The level of SOD gene expression in MW group was lower than the normal group within 6 days but that of GT group as higher than MW group. These results may imply that green tea stimulates SOD expression and there by protecting tissues from free radicals. The GSH-Px gene was expressed a little bit lower than the normal group but that of GT group was expressed to higher lever than MW group from 4 days after irradiation. These results suggest that the administration of green tea extract may activate antioxidative gene expressions such as SOD and GSH-Px in rat and that may help to recover liver tissues from microwave damage by removing hazardous free radicals and oxidized by products from cells.

• Food Science of Animal Resources
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• v.34 no.4
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• pp.403-407
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• 2014

Changes in Maillard reaction of pidan white were monitored with $A_{294}$, fluorescence intensity, and browning intensity during pickling in the absence and presence of Chinese black tea extract (Camellia sinensis) at levels of 2% and 5% together with 0.2% $ZnCl_2$ or 0.2% $CaCl_2$ up to 3 wk, followed by ageing for another 3 wk. Browning intensity and $A_{294}$ of pidan white increased with increasing pickling/ageing, while fluorescence intensity decreased during ageing (p<0.05), irrespective of treatments. At wk 6, pidan white treated with 0.2% $ZnCl_2$ and 0.2% $CaCl_2$ showed slightly higher browning intensity, fluorescence intensity and $A_{294}$ than those treated with divalents together with Chinese black tea (p<0.05). Free amino group and sugar contents showed continuous decrease during pickling and ageing irrespective of tea and cations used. However, pidan treated without Chinese black tea extract showed significantly lower free amino group and sugar during the ageing of 6 wk (p<0.05). Thus, Chinese black tea extract had an inhibitory effect on the Maillard reaction during ageing of pidan white.

• Journal of Nutrition and Health
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• v.35 no.8
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• pp.854-862
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• 2002

In the present study, we investigated the effects of chronic green tea consumption on the serum lipid profiles of 92 subjects (mean age: 59.5 $\pm$ 8.9, men: 41, women:51) living in a green tea cultivation village. The anthropometric and biochemical blood indices were measured, and nutritional intakes were assessed using 24-h recall method. Also, we administered a questionnaire regarding green tea consumption. The subjects were divided into three groups based on the period of green tea consumption (0, < 10 year, and $\geq$ 10 year). There were no significant differences in age, anthropometric indices (Wt, Ht, BMI, Body fat, LBM), and nutritional intakes among the groups. Serum LDL-cholesterol concentration was significantly lower in the $\geq$ 10 year group compared with the other groups (p < 0.05). Also, the LDL/HDL-cholesterol ratio was significantly lower in the $\geq$ 10 year group compared with the other groups (p < 0.05). The frequency of subjects with a normal range of serum LDL-cholesterol concentration (< 200 mg/dl) was significantly higher in the $\geq$ 10 year group compared with the other groups (p < 0.05). These results imply positive effects of chronic green tea consumption on blood lipid profiles, which requires confirmation in further studies.

• KSBB Journal
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• v.23 no.2
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• pp.131-134
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• 2008

Tea seed extract, a byproduct of tea processing, contains two kaempferol glycosides, camelliaside A and camelliaside B. Kaempferol was produced by enzymatic hydrolysis of glycosides. Optimum reaction conditions were investigated. $Pectinex^{(R)}100L$ was effective, producing kaempferol in 48 hrs. Optimum temperature and pH were $40^{\circ}C$ and 4, respectively. Ratio of substrate and enzyme affected the yield. Under optimum conditions, 1.6g kaempferol per 1 kg tea seed extract was produced and 80% of kaempferol precipitated. This result shows that kaempferol could be produced mildly and effectively using tea-processing byproduct.

• Integrative Medicine Research
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• v.3 no.1
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• pp.25-33
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• 2014

Background: Green tea contains numerous polyphenols, which have health-promoting effects. The purpose of this study was to evaluate the effect of tannase-converted green tea extract (TGE) formulation on the physical stability and activities of skin-related enzymes. Methods: Physical stability was evaluated by measuring the pH, precipitation, and colors at $25{\pm}2^{\circ}C$ /ambient humidity and at $40{\pm}2^{\circ}C$ \70%${\pm}$5% relative humidity for 4 months. Activities of collagenase, elastase, and tyrosinase as skin-related enzymes were assessed on TGE formulation. Results: The concentrations of epigallocatechin-3-gallate and epicatechin-3-gallate in green tea extract were greatly decreased to the extent of negligible level when treated with tannase. The formulation containing 5% tannase-converted green tea extract showed relatively stable pH, precipitation, and color features for 16 weeks. When TGE was added to the formulation, there was a significant increase in the inhibition of elastase and tyrosinase activities (p<0.05) compared with the formulation containing 5% normal green tea extract. Conclusion: The TGE could be used in cosmetics as skin antiwrinkling or depigmenting agent.

• Culinary science and hospitality research
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• v.9 no.4
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• pp.179-190
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• 2003

This study was performed to investigate the effects of dried powders of pine needle, pine pollen, green tea and horseradish on preservation of Kimchi-yangnyum. The physicochemical and microbial changes of Kimchi-yangnyum were investigated during 30-days preservation. The changes of pH, total acid, and number of total viable cell, lactic acid bacteria, E. coli of the Kimchi-yangnyum were insignificant. And the addition of pine needle powder were more effective to suppress fermentation than that of pine pollen or green tea or horseradish.

• Plant Disease and Agriculture
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• v.1 no.2
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• pp.26-28
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• 1995

Anthracnose of tea tree, Camellia sinensis, occurred severely at tea plantation of Boseung, Chonnam. Irregular, dark brown spots appeared on tips and margins of mature leaves in early stage. As the disease progresses, the lesions were covered with numerous, small, black, slightly raised pustules (acervuli). The causal fungus of anthracnose was identified as Colletotrichum theae-sinensis (Miyake) Yamamoto. Symptoms by C. theae-sinensis appeared around 20 days after artificial inoculation.

• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.48-53
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• 2005

Herbs and yucca(Yucca shidigera) are widely used a source of tea and otherwise such as botanical medicine, essential oil for perfumes, cosmetics, and food spices. This study was carried out to investigate the characteristics of herb tea prepared with lemon verbena, spearmint, apple mint, Korea mint, rosemary, pineapple sage, Chrysanthemum indicum, stevia, lavender, lemon balm cultivated in Korea and effects by addition of yucca. Approximate composition of yucca were as follows: moisture 5.88%, crude protein 5.46%, crude fat 0.69%, crude ash and 7.59%. pH of herb tea mixed yucca at 80℃ was decreased in lemon verbena, spearmint, apple mint, Korea mint, and rosemary in comparison herb tea alone, but soluble solids were similar in two tea. In the result of sensory test, herb tea and herb tea mixed Yucca were not difference with a few exceptions. pH of mentha(Korea mint) tea by addition of yucca was decreased according to increment amount of yucca. The sensory evaluation score of mentha tea by addition of yucca were increased when the tea was processed with 0.01∼0.04% yucca.