• Preventive Nutrition and Food Science
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• 제5권4호
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• pp.189-193
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• 2000

Preservative and antimutagenic effects of green tea leaves added Chinese cabbage kimchi (GK1, GK2, GK3, and GK4 : 1, 2, 3 and 4 of green tea leaves (GTL) in proportion of 100 of salted Chinese cabbage were added to kimchi) were compared to those of the Chinese cabbage kimchi without GTL (control kimchi, CK). Fermentation period of GKs was further delayed than that of CK. The initial pH and acidity between GKs an CK were similar, but the time reach optimally ripened status of kimchi (pH 4.3) was different. CK took 6 days, while GK1, GK2, GK3 and GK4 took 6, 10, 12 and 14 days at 10℃, respectively. The growth of Leuconostoc sp. and Lactobacilus sp. in GKs delayed comparing to those in FCK. Among GKs, as the added amount of green tea leaves increased, the growth of lactic acid bacteria was retarded. The antimutagenic effects of juices from GKs and CK were studied against aflatoxin B₁(AFB₁) in the Ames test on Salmonella typehimurium TA100 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the SOS chromotest using E. coli PQ37. Juices from optimally ripened GKs (pH 4.3) showed 52∼76% inhibition rates against the indirect mutagen, aflatoxin B₁ induced mutagenicity while 49% inhibition rate by CK in the Ames test. Juices from GKs and CK showed 44∼67% and 36% inhibition rate against direct mutagen, MNNG (70 ng/assay) induce mutagenicity in the SOS chromotest. Thus GKs delayed fermentation period of kimchi and exhibited higher antimutagenic activity than CK.

• Journal of Biosystems Engineering
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• 제41권4호
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• pp.365-372
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• 2016

Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.

• 한국식생활문화학회지
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• 제24권1호
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• pp.77-83
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• 2009

본 연구에서는 장뇌삼 엽차의 활용 가능성을 확인하기 위하여 장뇌삼 잎의 성분분석 및 장뇌삼 엽차의 항산화효과를 비교하였으며, 고지방식이를 공급한 흰쥐에게 장뇌산삼 엽차를 7주간 공급한 후 혈청의 지방대사에 미치는 영향을 검토하여 다음과 같은 결과를 얻었다. 장뇌삼 잎의 수분은 19.14%, 조회분은 6.64%, 조지방은 0.82%, 조단백질은 11.03%, 조섬유는 11.47%, 탄수화물은 62.37%를 나타내었고, 무기질 중에서는 칼륨이 2,111.38mg/100 g으로 가장 높은 함량을 나타내었다. 장뇌삼 잎에서는 카페인이 검출되지 않았으며, 1,170.48 mg/100 g의 탄닌이 함유되어 있으며, 조렉틴 함량은 5,540 mg/100 g으로 분석되었다. 전자공여능으로 측정한 항산화활성은 장뇌삼 엽차 추출물의 농도에 비례하여 증가하는 경향을 보였으며 특히 장뇌삼 엽차를 500 ppm로 처리 하였을 때에는 45% 이상의 높은 전자공여능을 나타내었다. 아질산염 소거능으로 측정한 항산화활성은 pH 3.0 보다 pH 6.0에서 높게 나타났으며, pH 6.0에서 250, 500, 1,000 ppm 농도로 처리했을 때 각각 23.47, 32.84, 51.41%를 나타내었다. 고지방식이를 7주간 급여하며 장뇌삼 엽차를 병행 투여하였을 때 식이섭취량은 고지방식이 급여 대조군과 장뇌삼 엽차를 병행 투여한 실험군 모두가 정상군에 비해 감소하였으며, 고지방식이 급여 대조군에 비해 장뇌삼 엽차 급여군은 약 6.4% 감소하였다. 체중 100 g당 간의 무게는 $3.11{\pm}0.29\;g$인 정상군에 비해 $4.82{\pm}0.08\;g$인 고지방 급여 대조군에서 유의적으로 증가하였으며, 장뇌삼 엽차 병행급여군도 고지방식이 급여 대조군과 유사한 경향을 나타내었다. 혈액 중 총 지방함량은 정상군에 비해 고지방식이 급여 대조군에서 66.2% 증가하였으며 장뇌삼 엽차 급여 시 고지방식이 급여 대조군에 비해 8.0% 감소를 나타내었으나 유의적이지는 않았다. 혈액 중 총콜레스테롤 함량은 정상군에 비해 고지방식이 급여 대조군에서 66.6% 증가하였으며, 장뇌삼 엽차 공급 시고지방식이 급여 대조군에 비해 감소하는 경향이었다. 혈액 중 중성지질 함량은 정상군에 비해 고지방식이 급여 대조군에서 172.5% 증가를 나타내었고, 장뇌삼 엽차 공급군은 고지방식이 급여 대조군에 비해 7.3% 감소하였다. 혈액 중 HDL-콜레스테롤 함량은 정상군에 비해 고지방식이 급여로 36.4%의 유의한 감소를 나타내었으며, 장뇌삼 엽차를 병행급여하였을 경우 정상군과 유사한 수준이었다. 이상의 결과에서 장뇌삼엽차의 항산화활성 및 지질대사 개선효과 등을 통해 장뇌삼엽차의 개발 및 산업화에 대한 기초자료를 얻었으며 추가 실험을 통한 연구가 필요할 것으로 사료된다.

• 한국식품과학회지
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• 제9권1호
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• pp.10-12
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• 1977

제차(製茶)의 품질에 관계되는 차엽(茶葉)의 화학 성분을 보성 및 광주지방의 차수(茶樹)에서 5월, 7월 및 8월에 각각 채취하여 분석한 결과는 다음과 같다. 총질소 및 ascorbic acid는 두지방 시료 모두 일번차(一番茶), 이번차(二番茶) 및 삼번차(三番茶) 순으로 감소하는 경향을 보였으나 조섬유 및 tannin은 반대로 증가하는 경향을 보였다. 환원당, caffeine 및 회분의 함량은 차엽(茶葉)의 채취 시기에 따라 별다른 변화를 보이지 않았다. 그러나 가용성 회분의 alkalinity는 증가한 반면에 불용성 회분의 alkalinity는 감소의 경향을 보였다. 차엽(茶葉)중의 아미노산 조성은 glutamic acid를 비롯하여 16종이 함유되어 있는바 이들은 채취 시기가 늦을 수록 감소하는 경향을 보였다.

• KSBB Journal
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• 제28권3호
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• pp.202-207
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• 2013

In this study, saponin content of extract from modified preconditioning process was investigated in Saponaria officinalis L. for cosmetic natural surfactant. Saponin content in steamed leaves from S. officinalis L. was about three times more than that in dried leaves (tea saponin and quillaja saponin). And saponin extracts from steamed leaves was excellently shown in both forming force and forming stability. In emulsion activity, saponin extracts from steamed leaves had a similar level to quillaja saponin and tea saponin. Saponin extracts from steamed leaves in S. officinalis L. showed nontoxic effect below in $1,000{\mu}g/mL$ of concentration and dose-dependent inhibition of NO production. From the experiment, the extracts of S. officinalis L. showed good cosmetic agent.

• 한국식품영양학회지
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• 제31권5호
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• pp.647-652
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• 2018

Extracts from bay leaves, Chongbaek (Allium fistulosum L.), Hutgae (Hovenia dulcis Thunb.) fruit, and green tea, using Soju (Korean alcohol, $30^{\circ}$) as a solvent were analyzed for their antioxidative properties. The eels were evenly coated with the extract concentration equivalent to 2% of their total weight and dried for 15 hours at $35^{\circ}C$ using an air blower. The DPPH radical scavenging effect, acid value and peroxide value of semi-dried eel, and linoleic acid peroxidation of eel oil were investigated. The highest level of DPPH radical scavenging was found in green tea extracts, followed by Hutgae fruit extract and bay leaves extract (p<0.05). The acid value and peroxide value of Hutgae fruit extracts coated eels refrigerated for 21 days were the lowest followed by the green tea extract coated eels. During the 20 days reaction period, all four kinds of extracts analyzed were found to effectively decrease linoleic acid peroxidation. Among them, Hutgae fruit and green tea extracts decreased the peroxide content of eel oil steadily and for a longer period when compared to other extracts. In conclusion, pre-application of Hutgae fruit and green tea extracts on eels before drying was found to be effective in delaying peroxidation in eels during the drying process and refrigeration.

• 한국식품영양학회지
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• 제23권2호
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• pp.178-185
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• 2010

Barley leaves tea white bread were prepared by the addition of 0.005, 0.010, 0.015, and 0.020% hemicellulase to flour of the basic formulation. The experiments and control were then compared in terms of quality characteristics, including pH, total titratable acidity, fermentation power of dough expansion, specific volume, baking loss, moisture content, color, textural characteristics, internal surface appearances, and sensory qualities in order to determine the optimal ratio of hemicellulase in the formulation. There were no significant differences in pH and total titratable acidity of dough and bread among the experiments. Fermentation power of dough expansion were increased as incubation time increased. Bread made by the addition of hemicellulase had significantly higher specific volume than the control group. However, lightness and yellowness showed the reverse effect. Greenness was not significantly different among the samples. Baking loss was the highest at the 0.020% addition level, and moisture content was maximal with the 0.010% addition, while the lowest in the control bread samples. As hemicellulase contents increased, harness and fracturability decreased. Resilience was maximal with the 0.015% addition, and was minimal in the 0.005% group. In the sensory evaluation, color, flavor, softness, overall acceptability, barley leaves flavor, delicious taste, astringency, bitterness, and off-flavor were not significantly different among the samples. In coclusion, the results indicate that adding 0.010% hemicellulase in barley leaves tea white bread is optimal for quality and provides a product with reasonably high overall acceptability.

• 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.

• 한국지역사회생활과학회지
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• 제19권3호
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• pp.365-371
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• 2008

This study was conducted to determine the potent physiological activity of traditional wild tea ("Don tea"; coin-shaped tea) as affected by different harvesting times, aging periods and extracting temperatures, No difference in anti-oxidative activities in the harvesting time and extracting temperature of tea leaves was observed. However, short aging periods of Don tea showed high ABTS {2-2-azonobis (3-ethylbenzothiazolin-6-sulphonic acid)} activity, ranging from 71.52 to 79.96%. DPPH (${\alpha},\;{\alpha}-diphenyl-{\beta}-picryl-hydrazyl$) radical scavenging activity of Don tea was 71.10 to 91.40%. Especially, longer aging period and an extracting temperature of $100^{\circ}C$ showed higher DPPH radical scavenging activity. With longer aging periods and an extraction at $90^{\circ}C$, nitrite radical scavenging activity of Don tea ranged from 74.04 to 94.92%. On the other hand, angiotensin 1-converting enzyme (ACE) inhibition activity of Don tea was 59.77-81.97%. It showed higher activity when harvested in June and August, aged for longer periods, and extracted at $100^{\circ}C$. These results suggested Korean traditional Don tea exhibited the highest physiological activity when aged over 8 months.

• Applied Biological Chemistry
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• 제33권4호
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• pp.277-281
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• 1990

차생엽을 첨가한 인절미 제조시험 결과 텍스쳐에서 경도, 탄성, 응집성, 씹힘성, 검성은 첨가량이 증가할수록 대체로 감소하여 차생엽에 의한 인절미의 치밀하고 쫄깃한 조직감이 약 간 부드럽게 변하였다. 관능검사 결과 색깔은 5% 첨가구가 엷은 녹색을 띠며, 5% 유의수준에서 가장 양호하였으며, 향은 10% 첨가구가 5% 유의수준에서 가장 좋았고, 조직감은 첨가구별 유의차는 없었으며 전체적인 관능품질은 5%와 10% 첨가구가 무첨가구와 15% 첨가구에 비하여 1% 유의수준에서 좋게 평가되었다. 저장기간중 인절미의 경도 변화는 차생엽 10% 첨가구가 무첨가구에 비하여 낮은 증가율을 보여 주었으며, Avrami 지수와 노화속도 상수를 구한 결과 무첨가구가 각각 1.062와 15.3인데 비하여 10% 첨가구는 0.989와 41.6으로 차생엽 첨가에 의하여 노화가 지연되는 것으로 나타났다.