• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.599-606
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• 1999

Water extracts of persimmon leaf tea(PLTE), green tea(GTE) and oolong tea(OTE), at the con centration used for human consumption, were examined for inhibitory effects on the mutagenicity of major classes of dietary and environmental mutagens including indirect acting mutagens, B[ ]P (benzo[ ]pyrene), IQ(2 amino 3 methylimidazo[4,5 f]quinoline), 2 AA(2 aminoanthracene) in the presence of S9 mix and direct acting mutagen, 4 NQO(4 nitroquinoline 1 oxide) without S9 mix, using the modified Ames Salmonella/microsome assay. PLTE, GTE and OTE showed very potent and concentration dependent antimutagenic effects against indirect acting mutagens B[ ]P and IQ. At the maximum concentration(16,200 g/plate) of each tea extract, number of colonies decreased in a dose dependent manner up to 82~100%. Similar inhibition of PLTE, GTE and OTE were seen at higher concentration in the mutagenicity of the 2 AA following an initial increase in the activity at lower concentration. However, the mutagenicity of the direct acting mutagen 4 NQO were not suppressed at lower concentration of the three tea extracts, and higher concentration of the tea extracts enhanced mutagenic activity of the mutagen. There were no differences in the mode of antimutagenesis between PLTE, GTE, and OTE, in both Salmonella typhimurium TA98 and TA100 strains against the same mutagen. In conclusion, the water extracts of persimmon leaf tea, green tea and oolong tea possess marked antimutagenic potential against a variety of important dietary and environmental indirect acting mutagens, but the activity was not observed against the direct acting mutagens. These results suggest that the mode of inhibitory action may not have resulted from direct interaction between tea extracts and the mutagens, but rather from indirect metabolic inactivation of mutagens by tea extracts.

• Food Science and Preservation
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• v.7 no.1
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• pp.99-102
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• 2000

Comparing and analysing the productivity and the main ingredients of persimmon leaves by cultivars were conducted to improve the quality and productivity of the per-simmon leaf tea. As a result of the survey, Dungsi was decidedly good in growth co-ndition of survival rate, stem diameter and the number of shoots etc. Also , DUngsi had the highest leaf productivity of 567 leaves and the leaf weight of 1.98 kg per one plant after three years of planting . On accounts of productivity, ingredient analysis and panel test etc. we collectively through that Dungsi was the best cutltivar for the persimmon leaf tea.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.273-279
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• 1999

Forty plants used as tea materials were chosen for determining the contents of total phenolics, selenium (Se), ${\beta}-carotene$, ${\alpha}-tocopherol$ and ascorbate. Total phenolics and ascorbate contents were analyzed colorimetrically. The Se contents were measured by hydride-atomic absorption spectrometry. The contents of ${\beta}-carotene$ and ${\alpha}-tocopherol$ were simultaneously determined by high performance liquid chromatography using separate detectors, UV for ${\beta}-carotene$ and FL for ${\alpha}-tocopherol$ analyses. The contents of these antioxidants were as follows (per 100 g dry plant); Contents of total phenolics in green tea leaf, black tea leaf, oolong tea leaf and instant coffee were about 7 g and the Se contents in corni fructus and arrowroot were found to be about $4{\mu}g$, which were the highest among all plants used. Contents of ${\beta}-carotene$ in eucommiae cortex, persimmon leaf and green tea leaf were 8587, 6222 and $3652\;{\mu}g$ respectively. The persimon leaf contained the highest ${\alpha}-tocopherol$ content (33 mg) and then followed by eucommiae cortex (26 mg), green tea leaf (16 mg) and black tea leaf (13 mg) in order. Ascorbate contents were found to be high in green tea leaf (199 mg) and black tea leaf (117 mg).

• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.28-35
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• 2011

The investigation of 218 residual pesticides for 19 types of tea (persimmon leaf tea, chrysanthemum tea, green tea, lavender tea, rosemary tea, dandelion leaf tea, puer tea, mulberry leaf tea, hydrangea leaf tea, jasmine tea, nuomixiang tea, buckwheat tea, mugwort tea, lotus leaf tea, oolong tea, longjing tea, rose tea, tiehkwanyin tea and huoguo tea) obtained from markets in Ansan and Suwon was carried out to assess the risk for residual pesticides in tea. The detection rate was 23.1 % (19 samples of total 65 tea samples) and the detected pesticides were 15 pesticides, such as bifenthrin, bromopropylate, chlorpyrifos, cyhalothrin, cypermethrin, chlorfenapyr, dicofol, endosulfan, fenpropathrin, fludioxonil, fenvalerate, iprobenfos, isoprothiolane, tetradifon and triazophos. The range of concentrations for the detected residual pesticides was 0.01 to 1.24 mg/kg which showed below their maximum residue limits (MRL), but the residual concentration of bifenthrin in a puer tea showed above the legal limit of 0.3 mg/kg. The result of risk assessment of residual pesticides for the detected 15 samples showed that EDI (estimated daily intake) of the pesticides detected ranged 0.0001~0.0844% of their ADI (acceptable daily intake).

• Korean Journal of Food Science and Technology
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• v.22 no.4
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• pp.405-410
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• 1990

The aroma components of duchung tea and persimmon leaf tea were collected simultaneous distillation and extraction method. Those were analyzed and identified by GC-MS using a fused sillica capillary column. Seventy seven components, including 17 alcohols, 3 hydrocarbons, 15 ketones, 16 aldehydes, 8 esters,8 acids, 8 heterocyclic compounds and 2 phenols were confirmed in duchung tea. Seventy one components, including 17 alcohols, 10 hydrocabrons, 11 ketones, 13 aldehydes, 8 esters, 6 acids, 5 heterocyclic compounds and 1 phenol were confirmed in persimmon leaf tea. The most abundant components of duchung tea were aldehydes(23.31%) including 2-pentenal and heterocyclic compounds(16.71%) including $epoxy-{\beta}-ionone$. The most abundant components of persimmon leaf tea were alcohols(25.57%) including linalool and aldehydes(19.45%) including hexanal and hydrocarbons(10.40%) including ${\alpha}-copaene$.

• Culinary science and hospitality research
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• v.14 no.2
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• pp.273-285
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• 2008

The purpose of this study was to find appropriate processing condition of astringent persimmon and persimmon leaf granular tea. Under the condition of 4 hour extraction and $50^{\circ}brix$, extraction yield and concentrating of astringent persimmon were the greatest. Under the condition of 2 hour extraction and $7^{\circ}brix$, extraction yield and concentrating of persimmon leaf were the greatest. The optimum condition of granular tea with astringent persimmon and persimmon leaf added was the best in astringent persimmon concentrate of 16% and persimmon leaf concentrate of 4%. It had the best taste after the condition in a brix value of 16.15% and a pH of 5.57. The L-value of chromaticity was -79.13, a-value 2.27, and b-value 2.41. In the sensory properties correlation analysis of astringent persimmon and persimmon leaf granular tea, sweet taste, color acceptability, odor acceptability and taste accept-ability were positively significant correlation with most sensory properties. However, astringent taste was no significant correlation with sensory acceptability. Bitter taste and after taste were negatively significant correlation with most sensory properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.720-726
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• 1995

Chemical components relevant to the characteristic taste of the Korean native persimmon(Diospyros kaki, Thumb) leaf tea were analyzed. Samples were processed by using three different methods ; SHT(steamed and then hot-air dried), DHT(dried in the shade, steamed and then hot-air dried) and RHT(roasted and then hot-air dried). The components analyzed were general compositions of dried perisimmon leaves and extracted solution. The composition of moisture, ash, crude lipid and total nitrogen did not show significant variation among different processing methods of the persimmonleaf tea. The contents of caffeine, tannin and vitamin C in persimmon leaf tea were in the range of $178.4~209.8{\mu}mol/g$, 29.1~38.5mg% and 325.3~2084.7mg%, respectively. The vitamin C content was significantly higher in the RHT than other treatments. The contents of caffeine, tannin and vitamin C in the tea extracted solution were in the range of $101.5~130.1{\mu}mol/g$, 15.4~25.9mg% and 111.0~1274.3mg%, respectively. The vitamine C in the tea solution was the highest in the RHT treatment and 61.1% of vitamin C in the leaf tea was extracted out in these processing methods. The major amino acids contained in the leaf tea were in decreasing order glutamic acid, aspartic acid, leucine and phenylalanine, these four amino acids consisting 38.9~39.8% of the total amino acid contained in the persimmon leaf tea. The major amino acids contained in the tea solution were glutamic acid, proline, histidine and arginine. Six kinds of 5'-nucleotides, CMP, AMP, UMP, IMP, GMP and hypoxanthine were detected and CMP was the most abundant component in fresh leaf, leaf tea and tea solution. The second highest 5'-nucleotides in both leaf tea and tea solutions were GMP, AMP and UMP in all processing method. The highest free sugar contained in the fresh leaf tea and tea solution was sucrose.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.468-471
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• 1998

Regarding the characterstics of allergic diseases, preventive and continuous treatment is desirable, and tea would be the one of the best functional food formula for it. Here we report the development of tea processing method for the leaves of Castnaea crenata. Two forms of Castnaea crenata leaf tea were prepared, non-fermented steaming tea and semi-fermented rolling tea. Anti-allergic actions of Castanea crenata leaf tea were asessed by testing their effects on the degranulation of mast cells. For this, hexosaminidase release (degranulation marker) from RBL-2H3 cells (mast cell line) was used. At the concentration of $300\;{\mu}g/mL$ of the water extract, the degranulation of RBL-2H3 cells were inhibited 50.4% and 35.4% by non-fermented steaming tea and semi-fermented rolling tea, respectively. These results suggest that the tea processing method we developed could provide a valuable resource for the treatment of allergic diseases.

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.185-190
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• 2003

Gamma irradiation was used as part of a new processing method to produce a brighter-colored and mild-flavored green tea leaf extract that retained all of its physiological activities. Dried green tea leaf was extracted with 70% ethanol and gamma irradiated at 0,5, 10, 20 kGy. Hunter color $L^{*}$- and $a^{*}$-values were increased with irradiation in a dose-dependent manner, which was a color range from dark brown to bright yellow. However, the irradiation effect gradually disappeared during 3 weeks of storage, with color reverting to that of untreated samples. There was no difference in the radical scavenging and tyrosinase inhibition effect by irradiation. Among antioxidants used, ascorbic acid was the most effective against color reversion. In contrast, cysteine was shown to protect the effect of color change with irradiation. Results indicated that enhanced color of irradiated green tea leaf extract can be effectively controlled by additives such as ascorbic acid and a low storage temperature.e.e.

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.15-24
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• 1993

(1) According to the history of three kingdoms, tea was introduced to Korea at the period of Korea at the period of Sun-Duck Queen of Shilla dynasty, and Dae-Ryeom Kim, the emissary, brought tea seeds from Tang China in 828, and sowed them on Mt. Jiri by the order of the King Heung-Duck, Shila. In 1885, The Chosun government took action in transplant 6000 each of tea of tea seeding from Ch'ing. (2) Transmission of schools As for the type of tea through the history of Korea, it could be characterized as cake-tea in the three kingdoms period, lump-tea in Koryo dynasty and leaf-tea in Chosun dynasty. Those were affected by Chinese tea culture. (3) Transfer of tea and tea utensils Kokuryo and Shilla had to import cake-tea from tang China, and Koryo had to import lump-tea from Sung China, and Chosun had to import leaf-tea from ch'ing China. On the other hand, to export various tea to Khitai, Chin, Yuan, and Chosun had to export tea Ch'ing China. And the tea bowl produced in the Sung such as Chien Chou ware and Chi Chou ware, was also introduced to Koryo. (4) Suggestion for the promation of tea industry The Chosun government were adviced to the exchange of Chosun tea for Chosun tea for China horse, by yang Ho, General to the Ming expeditionary forces in Chosun, and were advised to engage in foreign tea trade, by Lee Hong Jyand, minister of commerce for the nothern sea to the Ching.