• Food Science and Biotechnology
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• 제17권5호
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• pp.1016-1020
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• 2008

Parameters of soluble solids, amino acids, catechins, and color difference of 24 green tea samples from China and Korea were determined. The levels of soluble solids, amino acids, total catechins, and infusion lightness in tea samples from Korea were higher than those from China. Concentrations of epigallocatechin galate and epigallocatechin in teas from China were higher than tea samples from Korea. Geographical origin of teas from the 2 countries was discriminated using parameters of infusion lightness, gallocatechin, and total catechins and applying principal component analysis.

• Food Science and Biotechnology
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• 제14권1호
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• pp.1-5
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• 2005

Photostimulated luminescence (PSL), thermoluminescence (TL), electron spin resonance (ESR), and direct epiflourescent filter technique/aerobic plate count (DEFT/APC) were applied to detect dried green, black, and oolong teas irradiated between 0-10 kGy. Teas irradiated at 2.5 kGy and higher showed over 5000 photon counts/60 sec, while non-irradiated teas yielded 650-1000 photon counts/60 sec. TL glow curves for minerals separated from teas were detected at about $300^{\circ}C$ with low intensity in non-irradiated samples, whereas around $150^{\circ}C$ with high intensity in all irradiated samples. Ratio of $TL_1/TL_2$ based on re-irradiation step, showing lower than 0.1 and higher than 1.44 for non-irradiated and irradiated samples, respectively, enhanced reliability of TL results. ESR measurements for irradiated teas showed signals specific to irradiation. Log DEFT/APC ratio increased with irradiation dose; this result could be applied to identify irradiated tea samples.

• 한국식생활문화학회지
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• 제16권5호
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• pp.504-514
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• 2001

The contents of total flavonoids, total antioxidant status and superoxide scavenger activity of edible plants were measured. Among twenty one samples of leafy vegetables and teas, mugwort (Artemesia capillaris) and green teas gave high total flavonoids contents, 48.2 mg/g sample and 44.7 mg/g sample, respectively. The highest concentration of total flavonoids among eighty nine samples analyzed was 52.1 mg/g sample from propolis. When samples were tested for total antioxidant status, a kind of groundsel showed the highest Total Antioxidant Status(TAS) value, 13.4 mM among leafy vegetables and teas and green tea gave high TAS value, 11.84 mM. On the other hand, purslane gave the lowest TAS value, 0.01 mM. The superoxide scavenge activity was measured from the extracts of all edible plants. The superoxide scavenge activity of polygonatum(81.1%) and chrysantemum (78.5%) were the highest among leafy vegetables, teas and medicinalplants. On the other hand, ginseng, poria, cassiae semen and dioscoreae rhizoma showed no superoxide scavenge activities.

• 한국식품영양과학회지
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• 제25권3호
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• pp.478-483
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• 1996

The aroma components of Korean green tea in the south western part of Mt. Chiri prepared by the traditional method from native variety were analyzed using GC and GC-MS. The patterns on GC chromatograms of the three samples from the flushes plucked in early spring were similar, though they are prepared by different producers in the area of Hadong-kun, Kyung sang nam-do. A total of 51 aroma compounds were identified in all samples. Main component in the aroma compounds of these teas were geraniol, benzyl alcohol, 2-phenylethanol, $\beta$-ionone, benzyl cyanide and linalool oxides. The aroma components of green teas manufactured by the different plucking periods were also compared. The amounts of geraniol, typical rose floral aroma were particularly decreased in the final plucking period. The amounts of pyrazines and furfuryl alcohol, typical roasted aroma and nutty aroma were slightly increased in later plucking period.

• 한국식품영양과학회지
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• 제21권4호
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• pp.386-389
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• 1992

녹차에 있어서 맛성분으로도 중요하고, 최근에는 그 약리작용의 연구과 활발히 연구되고 있는 catechin의 함량 분석을 국산 시판 녹차를 시료로 하여 시도하였다. 100mg의 시료 분말 녹차를 열수 출출한 후 $CHCl_3$를 가하여 시료 용액으로 부터 caffeine를 제거시키고 EtOAc를 가하여 catechin류를 추출 농축하여 5ml로 한 다음 $0.45\;\mu\textrm{m}$ membrane filter를 통과시킨 후 $2\;\mu\textrm{l}$을 HPLC에 주입시켰다. 4종류의 고순도 정량분석용 catechin류를 표준용액으로 한 검량선법에 의하여 시료중의 catechin 함량을 구하였다. 그 결과, EGCg의 함량(찐 1번차 : 7.54%, 볶은 1번차 : 7.88%)이 가장 많았고 EGC, ECg, EC의 순서로 그 함량이 감소하엿다. 수확시기가 늦은 2번차에서는 EGCg, ECg 와 같은 gallate는 증가하고 EGC는 약간 감소하는 경향을 나타내어 차의 맛에 영향을 주는것 같다.

• KSBB Journal
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• 제16권2호
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• pp.163-169
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• 2001

This study was undertaken to evaluate the effects of green and taste teas on the in-vitro antimicrobial activity and vacuolating toxin titer of Helicobacter pylori. Crude aqueous extracts prepared by adding 2 g of tea leaf or powder to 100 ml of boiling distilled water, and sterilized by passing through a 0.22 $mutextrm{m}$ membrane filter. Green tea, coffee, and ginger tea showed bactericidal activity on H. pylori within 3 hours. Black tea and ssangwha tea also showed bactericidal activity on H. pylori in 24 hours. Arrowroot tea show no bactericidal effect on H. pylori after 48 hours. Two fold diluted green tea and coffee decreased(1/10,000cfu) the growth of H. pylori in 24 hours, but the two fold diluted black tea, ssangwha tea, and ginger tea showed suppression effect upon of(1/10cfu) H. pylori in 24 hours. The two-fold and 10-fold diluted green tea, coffee and two-fold diluted black tea abrogated the vacuolating toxin titer of H. pylori, but the two-fold and 10-fold diluted ginger, ssangwha, ginseng, and arrowroot tea only reduced the vacuolating toxin titer of H.pylori from 1/2 to 1/8. These result suggest that green tea and coffee have effective antibacterial or bactericidal effects on H.pylori, and that they also have a neutralization effect upon the vacuolating toxin of H.pylori.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.

• 한국식품영양과학회지
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• 제32권5호
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• pp.723-727
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• 2003

본 연구에서는 일상생활에서 손쉽게 음용할 수 있는 차 추출물에 대해 항산화력과 항산화 성분의 함량을 측정함으로써 그 상관관계를 알아보고자 하였다. 차 추출물의 항산화력은 ABTS 와 DPPH radical을 사용하여 측정하였으며, 항산화력 성분은 총 폴리페놀, 총 플라보노이드, 총 비타민 C 함량을 각각 측정하였다. 총 폴리페놀 함량은 홍차, 허브티 I, 녹차 I, 허브티 II, 녹차 II, 한차 I에서 101.51~62.60 mg범위로 다른 차에 비하여 높게 나타났으며, 총 플라보노이드 함량은 허브티 II, 한차 I, 홍차에서 높은 함량을 나타내었다. 반면 총 비타민 C의 경우 한차 I이 15.78 mg을 나타낸 제품을 제외 하고 다른 것들은 모두 낮은 함량을 나타내었다. 항산화력이 높게 나타난 차는 주로 녹차류와 홍차였으며 이들의 항산화력에 기여하는 물질이 주로 비타민 C나 플라보노이드가 아닌 폴리페놀성 화합물임을 알 수 있었다.

• 한국작물학회지
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• 제51권spc1호
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• pp.215-219
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• 2006

전국에서 수집한 쑥들에 대한 항산화력과 항산화성분 함량을 비교 분석하여 유효 약용성분을 다량 함유하는 우량계통을 선발한 후 대량 재배하였고, 한방건강식품으로 쑥차를 개발하였다. 개발된 쑥차의 우수성을 알아보기 위해 시판되고 있는 차들을 구입하여 항산화력과 항산화성분 함량을 비교 분석하는 실험들을 수행하였다. 수집 선발한 쑥 AC60, AC67, AC77을 원료로 하여 만든 차들과 시판 차들의 총 폴리페놀 함량들을 분석한 결과 AC67의 총 폴리페놀 함량이 109.6 mg/100 mL로 가장 높았다. 선발 쑥차들의 아질산염 소거능은 선발 쑥 중에서는 AC67가 PH 1.2에서 92.5%로 가장 높았고, 시판 차들 중에는 쟈스민이 98.1%, 감잎차가 96.4%, 녹차가 98.5%, 작설차가 98.7%로 매우 높은 값들을 보여 주었다. SOD 유사 활성을 비교해 본 결과 선발 쑥을 원료로 하는 차들에서는 AC67가 91.7%, AC77이 93.7%로 높았고, 시판 차들에서는 설록차가 92.1%, 루이보스티가 93.8%로 높게 나왔다. 이 결과는 선발 쑥 AC60, AC67, AC77 등은 시판 중인 설록차, 자스민, 작설차, 녹차, 루이보스티 및 페퍼민트차 등과 같은 수준의 고급차의 제조에 이용성이 높을 것으로 생각되었다.

• Journal of Nutrition and Health
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• 제32권4호
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• pp.337-352
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• 1999

The effects of dried leaf powders and ethanol extract of persimmon, green tea and pine needle on lipid metabolism, lipid peroxidation and antioxidative activity were investigated in rats. Forty-nine male Spargue-Dawley rats weighing 107.8$\pm$1.8g were blocked into seven groups according to body weight. Rats were raised for four weeks with diets containing either 5%(w/w) dried leaf powders of one of three different Korea traditional teas, persimmon(Diospyros kaki Thunb), green tea(Camellia Sinensis O.Ktzc)or pine needle(pinus Koreansis Sieb. Et Zucc), or ethanol from equal amounts of each dried tea powder. Food intake, weight gain, food efficiency ratio, and weights of liver, kidney and epididymal fat were significantly higher in the green-tea-powder group, and significantly lower in the pine-needle-powder and pine-needle-extract groups. Persimmon-leaf powder was found to decrease plasma total lipid, triglyceride and cholesterol concentration by increasing fecal total lipid triglyceride and cholesterol excretions. Liver cholesterol concentration was significantly lower in the green-tea and pine-needle-extract groups. Red-blood-cell superoxide dismutase(SOD) and glutathione peroxidase(GSH-px) activities were significantly increased in rats fed green-tea extract. Liver SOD activity was increased in rats fed pine-needle powder or extract, and liver GSH-px activity was increased in rats fed greentea powder. Plasma and liver thiobarbituric acid reactive substance(TBARS) concentration were both decreased in rats fed dried leaf posers or extracts of persimmon or green tea. It is believed that high vitamin E levels in persimmon leaf, and high flavonoid, beta-carotene and vitamin C levels in green tea effectively inhibited lipid peroxidation. In conclusion, persimmon and green tea leaves were effective in lowering lipid levels and inhibiting lipid peroxidation in animal tissue, while pine needles were effective and lowering body weight gain. From these results, persimmon and green tea leaves can be recommended in the treatment and prevention of chronic discorders such as cardiovascular disease, cancer and aging. As ethanol extracts from these teas were also effecitive in lowering tissue lipid levels and inhibiting lipid peroxidation, we recommend the use of discarded tea grounds for this.