• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.20-23
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• 1999

This study was conducted to investigate the content and composition of tea catechins at different plucking time and different position of tea leaves. The bud and first leaf, second leaf, third leaf, and fourth leaf were collected on May, July, and August. The catechin content was highest in leaves picked on August among those collected from different months. When compared with the different part of tea leaves, the bud and the first tea leaf contained the highest catechin, and the fourth left contained the lowest catechin. Analysis of catechin composition in the tea leaves, showed that epigallocatechin gallate was the highest, and the other contents were following order: epicatechin gallate, epicatechin, epigallocatechin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.58-61
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• 2003

Moisture content was 79.5%, banjhi shoot was 77.8% of the total and the weight was 29.4 g/100 buds in the harvested plant leaves used for manufacturing Okro tea. Okro tea heated at 75$^{\circ}C$ for 30 min showed the best quality among all the treatmants. Chemical components such as total nitrogen, theanine, arginine and chlorophyll were high in the tea treated at 75$^{\circ}C$ for 30 min compare with those of other treatments. The sensory evalution test In terms of appearance shape color and taste showed greater preferences in Okro tea treated at 75$^{\circ}C$ for 30 min than those of other treatments. The results suggested that heat treatment at 75$^{\circ}C$ for 30 min was the best condition for the final rolling process in manufacturing of Okro tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.2
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• pp.261-267
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• 1994

Parched mugwort tea was manufactured from mugwort (Artemisia asicatica nakai) leaves by traditional green tea preparation method. Volatile flavor compounds were collected by Tenax GC and they separated on DB-5 capillary column ($60m\;\times\;0.25mm$ i.d.) Fifty eight compounds were isolated and identified by GC-MS from the volatiles. Eleven compounds incucluding benzaldehyde, pinene, myrcene, cineole, 2-phrrolidinonoe, camphor, thujong, 1-acetylpiperidine, caryophyllene, coumarin, and farnesol among the compounds identified were considered as important compounds contributing mugwort-like flavor to the parched mugwort tea. The mixture of these eleven authentic compounds could reproduce aroma of mugwort leaves harvested in April. As results, the concentrations of these eleven flavor compounds in parched mugwort tea may indicate the strength of mugwort-like aroma of the tea.

• Biomedical Science Letters
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• v.27 no.4
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• pp.248-254
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• 2021

Ulcerative colitis (UC), chronic inflammatory bowel disease, is characterized by severe inflammation in the colon. Tea is one of the most popular beverages consumed worldwide. Pu-erh tea, a unique Chinese tea produced by microbial activities, possesses a broad range of health-promoting effects, including anti-aging, anti-Alzheimer's disease, antioxidation and anti-obesity. However, the inhibitory effect of Pu-erh tea on intestinal inflammation and the underlying mechanism remain unclear. The present study was designed to evaluate the regulatory effect of Pu-erh tea extract (PTE) on dextran sulfate sodium (DSS)-induced colitis clinical signs by analyzing the weight loss and colon length in mice. The inhibitory effects of PTE on inflammatory mediators, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, and the activation of nuclear factor-κB (NF-κB) were also determined in DSS-treated colitis tissue. We observed that PTE treatment significantly inhibited the DSS-induced clinical symptoms of weight loss, decrease,in colon length, and colon tissue damage in mice. Moreover, PTE attenuated the DSS-induced levels of IL-6 and TNF-α in colon tissue. We also demonstrated the anti-inflammatory mechanism of PTE by suppressing the activation of NF-κB in DSS-treated colon tissues. Collectively, the findings provide experimental evidence that PTE may be effective in preventing and treatment of intestinal inflammatory disorders, including UC.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.856-861
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• 2002

It has been reported in animal and human studies that green tea shows a health protective characteristics. In the present study, we investigated the disease prevalence according to chronic green tea consumption in 92 subjects (mean age: 59.548.9, men: 41, women: 51) living in green tea cultivation village. The consumption of green tea and other life-style characteristics were ascertained by a questionnaire. The subjects were divided into three groups according to the period of green tea consumption (0, < 10 year, and $\geq$ 10 year). For green tea consumption groups, most of the subjects have been drinking green tea in order to protect disease and recognized the effects of green tea as detoxification of alcohol and smoking, protection of cold or release from fatigue. There were no significant differences in drinking and smoking, physical activity, and a cold prevalence among the groups. Green tea consumption was associated with lower levels of prevalence of tooth decay as well as the osteoporosis. The score of dietary habits was higher by increasing green tea consumption period (p<0.05). Consequently, chronic green tea consumption can be considerably effective in health promotion.

• Food Science and Preservation
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• v.23 no.3
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• pp.335-340
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• 2016

This study was carried out to investigate the physicochemical and quality characteristics of acorn and acorn tea by processing methods. The moisture contents of acorn tea processed roasting was lower than those of others, and acorn tea processed by three steaming and drying was highest in among. Carbohydrate and crude lipid, crude ash contents of the acorn tea processed by roasting was higher than those of others. Crude protein contents of the natural acorn was higher than those of others. Soluble protein content of acorn tea produced by three steaming and drying was 12.74 mg/g, where was highest than that of the acorn tea. Reducing sugar content of natural acorn was 64.3 mg/g, higher than that of the acorn tea. The L values of natural acorn was higher than those of others, but steaming and roasting acorn tea were lower than those of others. The a, and b values of natural acorn was higher than those of others. Total polyphenol and flavonoid contents of acorn tea processed by three steaming and drying was 41.15, 2.78 mg/g, where was higher than that of the acorn tea. Sensory test was the acorn tea produced by three steaming and drying showed the best score in preference.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.499-512
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• 2001

This study was performed to investigate effects of dried leaf powders, water, 75% and 95% ethanol extracts of persimmon leaf and green tea on lipid metabolism, lipid peroxidation and antioxidative enzyme activity in 12-month-old rats. Fifty-four male Sprague-Dawley rats weighing 542$\pm$4.5g were blocked into groups according to their body weight and were raised for four weeks with the diets containing 5%(w/w) dried leaf powders of persimmon(Diospyros kaki Thunb) and green tea(Camellia Sinensis O. Ktze), water or 75% and 95% ethanol extracts from same amount of each dried tea powder. Food intake was not significantly different among all groups, but weight gain of green tea powder group was significantly lower than that of control group. Plasma and liver lipid levels of all the tea diet groups were lower than those of control group. Especially, 75% ethanol extract of persimmon leaf decreased total lipid and triglyceride concentrations in plasma and 95% ethanol extract of persimmon leaf decreased liver total lipid level. However, there was no difference between 75% ethanol extracts groups and 95% ethanol extracts groups in lipid metabolism. Superoxide dismutase(SOD) and catalase activities in erythrocyte were remarkably increased by all the green tea diets. SOD, catalase and glutathione peroxidase activities in liver were increased by the feeding of ethanol extracts from green tea and persimmon leaf powder. Liver xanthine oxidase activity was not different among all groups. Plasma Thiobarbirutic acid reactive substance(TBARS) concentrations of all the green tea diet groups were significantly low. It was thought that high flavonoids in green tea inhibited plasma lipid peroxidation by promoting SOD, catalase activities in erythrocyte. 95% ethanol extract of persimmon leaf also inhibited plasma lipid peroxidation by high vitamin E and beta-carotene. Persimmon leaf powder decreased liver TBARS concentration by vitamin E, betacarotene and vitamin C and by increasing activities of antioxidative enzymes with flavonoids. In conclusion, dried leaf powders, water, 75% and 95% ethanol extracts of persimmon leaf and green tea were effective in lowering lipid levels and inhibiting lipid peroxidation in 12-month-old rats. Above all, ethanol extracts of persimmon leaf decreased plasma and liver lipid levels and persimmon leaf powder effectively inhibited liver lipid peroxidation. Extracts of green tea leaf inhibited plasma lipid peroxidation. In lowering lipid levels and inhibiting lipid peroxidation, ethanol extracts were more effective than water extracts, but there was no difference between 75% ethanol extracts and 95% ethanol extracts in lipid metabolism. (Korean J Nutrition 34(5) : 499~512, 2001)

• Journal of Life Science
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• v.20 no.9
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• pp.1415-1419
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• 2010

Consumption of green tea has increased along with increasing concern regarding healthier lifestyles, and many brands of green tea are sold with a label indicating the region of Korea in which the tea was produced. However, there is little information on identifying the difference between the green tea cultivars according to the region they were grown. Here, 9 green tea cultivars collected from Hadong region, Bosung region, China and Japan were subjected to the STS-RFLP analysis. Using the coding and noncoding DNA regions of genes related to the phenylpropanoid pathway, such as phenylalanine ammonia-lyase, chalcone synthase and dihydroflavonol 4-reductase, we have identified the differences between green tea cultivars according to the region they were grown in. In this study, we showed a STS-RFLP method of green tea analysis which easily distinguished different kinds of tea using the primers as described. In addition, we identified that the green tea cultivars from Hadong and Bosung displayed a different profile when PAL intron was digested with Dde I, suggesting that a rapid authentication system for green tea cultivars grown in different regions in Korea is available.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.115-115
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• 2001

Regular green tea consumption has been associated with a reduced risk of cancer, partly via antioxidant effects of green tea in protecting cellular components against free radical. In the present study, we evaluated the effect of green tea extract (GTE) on oxidative damage to DNA in CHL cells.(omitted)

• Food Science and Preservation
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• v.5 no.1
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• pp.97-104
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• 1998

The chemical structure of low molecule polyphenol of tea was found as explained. Structure decision of pioanthocyanidin was possible to measure 1,700 molecule, hexamer by chemical basic of polyphenol. At present, structure of high molecule than of that can't be suspected and it is concemed that strong astrigent ccnpound of tea is polymer proanthocyanidin. Mush researches was required in structure decision and isolation of high molecule polyphenol complex. Structure decision will develope at the natural products in the furture.