• Food Quality and Culture
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• 제2권2호
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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.

• 한국의류산업학회지
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• 제8권3호
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• pp.343-348
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• 2006

This study aims to attain gray tone dyed goods by using tannin that is contained in green tea. Tannin is given general name of polyphenol, which has a characteristic that bonds with protein and it is used for food preservative that protects against bacteria, as well as its purpose of black tone dye for silk treatment that has been processed since its early ages. In particular, as tannin reacts with all kinds of metallic mordant and changes to various colors, when tannin acid is combined with iron, it becomes tannin steel and produces gray tone color. Tannin that is contained in green tea is condensed tannins and its structure does not hydrolyze, thus having flavan type structure. In order to find the suitable condition for processing tannin, UV-Vis part absorption spectrum of green tea tannin, dye ability based on temperature and time, reflection rate based on concentration, color changes based on acid treatment and alkali treatment, changes on surface based on concentration or metal mordant condition, and lightfastness were measured. Maximum absorption wavelength (${\lambda}_{max}$) of green tea tannin was at around 273nm, while strong absorption was also observed at below 350 nm. Dye ability of green tea tannin is done more easily on silk rather than cellulose fibers such as cotton, while the optimum condition for dyeing was observed to be at $60^{\circ}C$, for 20 minutes. As a result of acid treatment, the color of dye material consisted highly of gray tones and showed overall gray tone with the combined color of yellow and red after the alkali treatment. While it was observed that as dye concentration and metal mordant concentration increased, the color changed at counter-clockwise direction on the Y-scale of Munsell's scale of colors. Additionally, lightfastness was more on a normal fading.

• Asian-Australasian Journal of Animal Sciences
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• 제27권11호
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• pp.1571-1576
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• 2014

Nutritive values of green and black tea by-products and anti-nutritive activity of their tannins were evaluated in an in vitro rumen fermentation using various molecular weights of polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP) and polyvinyl polypyrrolidone as tannin-binding agents. Significant improvement in gas production by addition of PEG4000, 6000 and 20000 and PVP was observed only from black tea by-product, but not from green tea by-product. All tannin binding agents increased $NH_3$-N concentration from both green and black tea by-products in the fermentation medium, and the PEG6000 and 20000 showed relatively higher improvement in the $NH_3$-N concentration. The PEG6000 and 20000 also improved in vitro organic matter digestibility and metabolizable energy contents of both tea by-products. It was concluded that high molecular PEG would be suitable to assess the suppressive activity of tannins in tea by-products by in vitro fermentation. Higher responses to gas production and $NH_3$-N concentration from black tea by-product than green tea by-product due to PEG indicate that tannins in black tea by-product could suppress rumen fermentation more strongly than that in green tea by-product.

• 한국식품조리과학회지
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• 제15권2호
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• pp.95-101
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• 1999

This study was carried out to prepare green teas by traditional roasting manufacturing process, Ku Geung Ku Po and to determine the quality charateristics of the green teas by examining the change of their main components induced during this roasting process. The content of total sugars in unroasted tea leaves was 7.82%. Its content of roasted teas was decreased by increasing the number of roasting and there was significantly differences between samples. The content of total sugars in 9th roasted green tea was 3.98%. The total nitrogen contents of green teas produced by this process were 4.96∼6.38%. The more the number of roasting and the less content of tannin in green teas. And the ratio of total nitrogen and tannin in tea leaves 21.97 but its ratio in 9th roasted tea was increased to 45.54. The ascorbic acid in tea leaves consisted in 1,820.3 mg/100g but its content was decreased by increasing the number of roasting process. Whereas the content of caffeine in green teas was not reduced significantly by this traditional method. Of all amino acids, green tea produced by Ku Jeung Ku Po was rich glutamic acid, lysine and aspartic acid. And especially, phenylalanine, which was rarely found in other green teas, was abundant in these green teas. The compositions of glutamic acid and methionine were increased as increasing the number of roasting process but those of aspartic acid and arginine decreased by these processing. The main fatty acids of Ku Jeung Ku Po green tea were linolenic acid, linoleic acid and palmitic acid and the contents of unsaturated fatty acid in green teas were composed over 70% of total fatty acid. And the fatty acid contents in green teas were not affected during Ku Jeung Ku Po's process. The contents of minerals in these teas was rich in the oder of potassuim. magnessuim and calciumim, and these contents were not observed the prominant change during the process.

• 한국식생활문화학회지
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• 제4권4호
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• pp.411-416
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• 1989

적채시기별 녹차의 침출조건에 따른 유리당, 총질소 및 탄닌함량은 침출온도$(55{\sim}95^{\circ}C)$가 높을수록 침출시간(30초${\sim}$10분)이 길수록 증가하였다. 침출조건에 따른 녹차의 관능검사 결과 유리당 및 총 질소는 유의성 있는 상관관계가 나타나지 않았으나 탄닌함량과는 $15{\sim}30mg/g$의 농도에서 변곡점을 형성하는 유의성 있는 상관관계(r=-0.9061)을 나타내었다. 탄닌함량과 관능검사에 의한 녹차의 최적 침출조건은 상급차의 경우 낮은 온도$(55{\sim}75^{\circ}C)$에서 단시간 ($0.5{\sim}1$분)이었고 중급차는 $85^{\circ}C$ 이하에서 2분 이내가 최적 조건이었다.

• 한국식품영양과학회지
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• 제12권2호
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• pp.99-104
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• 1983

1982년(年) 8월(月) 장성지방에서 수휴(收携)한 차엽(茶葉)으로 전통적(傳統的)인 볶음차(茶) 제조방법(製造方法)과 상업적(商業的) 제조방법(製造方法)에 따라 각각(各各) 녹차(綠茶)와 홍차(紅茶)를 제조(製造)하고 생엽(生葉)과 녹차(綠茶), 홍차(紅茶)의 주요성분(主要成分)인 tannin, caffeine 총(總)아미노산 유리당(遊離糖)의 함량변화(含量變化)를 측정(測定), 비교(比較), 검토(檢討)하였다. 1. 녹차생엽(綠茶生葉), 녹차(綠茶), 홍차생엽(紅茶生葉), 홍엽(紅葉)의 tannin 함량(含量)은 각각(各各) 11.79%, 12.03%, 7.89%, 3.43%로 제조후(製造後) 녹차(綠茶)에서는 2% 증가(增加)하였고, 홍차(紅茶)에서는 56.5%가 감소(減少)하였다. 2. 녹차생엽(綠茶生葉), 녹차(綠茶), 홍차생엽(紅茶生葉), 홍차(紅茶)의 caffeine 함량(含量)은 각각(各各) 2.05%, 2.58%, 1.63%, 1.58%로 제조후(製造後) 녹차(綠茶)에서는 25.9% 증가(增加)하였고, 홍차(紅茶)에서는 3.1% 감소(減少)하였다. 3. 녹차생엽(綠茶生葉), 녹차(綠茶), 홍차생엽(紅茶生葉), 홍차(紅茶) 의 총유리당(總遊離糖) 함량(含量)은 각각(各各) 115.78mg/g, 25.19mg/g, 120.72mg/g, 28.18mg/g 으로 제조후(製造後) 녹차(綠茶)와 홍차(紅茶)에서 각각(各各) 78.2%, 76.7% 감소(減少)하였다. 4. 녹차생엽(綠茶生葉), 녹차(綠茶), 홍차생엽(紅茶生葉), 홍차(紅茶)의 총(總) 아미노산 함량(含量)은 각각(各各) 279.59mg/g, 206.52mg/g, 120.54mg/g, 97.84mg/g으로 제조(製造) 후(後) 녹차(綠茶)와 홍차(紅茶)에서 각각(各各) 26.1%, 18.8% 감소(減少)하였다.

• 대한가정학회지
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• 제23권2호
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• pp.29-36
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• 1985

This experiment was conducted to investigate changes of the components in steamed and roasted green tea after 10 min, 20 min and 30 min of heat treatment of heat treatment at $110^{\circ}C$. Vitamin C and tannin were determined by spetrophotometry. Total nitrogen, water-soluble nitrogen and water-soluble non protein nitrogen were determined by Kjeldahl analysis system. Aromas were identified by gas chromatography. After heat treatment, contents of most compounds decreased. Tannin and caffeine decreased a little bit, while vitamin C decreased considerably. There were both decreases and increases in aromas. Aromas which increased were geraniol, trans-2-hexenol, linalool, $\alpha$-ionone and $\beta$-ionone. From these results, it was concluded that the highest quality of green tea was one steam- treated for 10 min at $110^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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• pp.937-945
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• 2014

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at $10^{\circ}C$. The GTS stored at $20^{\circ}C$ and $30^{\circ}C$ showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on $NH_3$-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and $NH_3$-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and $NH_3$-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin's activity in the rumen.

• 한국지역사회생활과학회지
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• 제19권1호
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• pp.55-61
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• 2008

This study was conducted to compare the nutrient and chemical contents of traditional Chungtaejeon tea with that of green tea which was harvested in Jangheung, Jeonnam district. Vitamin C, amino acids and total nitrogen contents of Chungtaejeon tea were lower than that of green tea by 0.30, 2.30 and 4.20g/100g, respectively. The tannin, caffeine, reducing sugar and chlorophyll contents in Chungtaejeon tea were the same as those in green tea. Comparing catechin contents, catechin (C), epicatechin (EC), and epigallocatechin (EGC) in Chungtaejeon tea were lower than those of green tea. However, gallocatechin (GC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and catechin gallate (CG) showed no significant difference between Chungtaejeon tea and green tea. The flavonoid contents of Chungtaejeon tea and green tea showed higher quercetin and kaempferol contents in green tea, and higher myricetin content in Chungtaejeon tea. The measured amino acid contents for threonine and aspartic acid were lower, and for glutamic acid were higher in Chungtaejeon tea compared with those in green tea. However, free amino acid content in Chungtaejeon tea and green tea showed no significant difference. Potassium and magnesium contents in Chungtaejeon tea were lower compared to green tea but no significant difference was found for iron, manganese or calcium contents when comparing the two teas.

• 대한가정학회지
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• 제25권1호
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• pp.51-58
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• 1987

This study was undertaken to investigate changes in blood pressure and heart rate in normal cats by administration of Korean native green tea. The chemical components of Korean native green tea which determined are water(2.2%), water extract(32.7%), vitamin C(480%), caffeine(2.6%), tannin(32.7%) and amino acid of water soluble content 5.8%. Effect on blood pressure in administration 100mg/kg, 300mg/kg, 500mg/kg of extract of green tea, the mean depressor response is 44.8$\pm$3.3mmHg, 60.5$\pm$3.6mmHg, and 65.0$\pm$3.3mmHg in normal cats. Effect on heart rate in administration 100mg/kg, 300mg/kg of extract of Korean native green tea, the mean decreased heart rate is 2.8$\pm$4.5 beats/min, 15.2$\pm$6.4beats/min and 19.1$\pm$4.0 beats/min.