• Nutrition Research and Practice
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• 제13권5호
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• pp.393-398
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• 2019

BACKGROUND/OBJECTIVES: The association between tea consumption and risk of coronary heart disease (CHD) remains controversial. This study aimed to determine whether tea consumption has an effect on CHD risk in Chinese adults. SUBJECTS/METHODS: In this hospital-based case-control study, 267 cases of CHD and 235 non-CHD controls were enrolled. Blood samples from all cases were examined. Cardiac function indices (left ventricular ejection fraction, left ventricular end-diastolic dimension, lactate dehydrogenase, and creatine kinase of the muscle or brain type), blood lipid index (high-density lipoprotein cholesterol), and blood coagulation function indices (fibrinogen and activated partial thromboplastin time) were recorded. Tea consumption of study participants was assessed by a specifically designed questionnaire. The baseline characteristics of the study populations were recorded, and CHD-related biomarkers were detected. Differences in baseline characteristics of the study participants were examined using t-tests for continuous variables and chi-squared tests for categorical variables. Unconditional logistic regression was used to measure the association between tea and CHD. RESULTS: There were significant differences in cardiac function indices, blood lipid index, and blood coagulation indices between CHD cases and controls (P < 0.05). We found tea consumption reduced CHD risk in female participants (adjusted odds ratio (OR) = 0.484, 95% CI: 0.242-0.968, P = 0.0403). Regarding the type of tea consumed, the risk of CHD was reduced in women who drank partially fermented tea (adjusted OR = 0.210, 95% CI: 0.084-0.522, P = 0.0008). Analytic results for the amount of tea consumed per unit time showed CHD risk was reduced in women who consumed 1-2 cups of tea per day (adjusted OR = 0.291, 95% CI: 0.131-0.643, P = 0.0023). A tea-drinking frequency of > 6 days/week was beneficial for CHD prevention (adjusted OR = 0.183, 95% CI: 0.049-0.679, P = 0.0112). When analyzed according to the duration of tea consumption, the risk of CHD was reduced in participants who had been drinking tea for 10-20 years (adjusted OR = 0.360, 95% CI: 0.137-0.946, P = 0.0382). CONCLUSIONS: Tea consumption is associated with a reduced risk of CHD in female but not male populations in Guangzhou.

• Nutrition Research and Practice
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• 제2권4호
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• pp.234-239
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• 2008

The purpose of this study was to investigate the effects of green tea ingestion on hepatocarcinogenesis before and after its initiation. Male Sprague-Dawley rats were fed an AIN76A diet with or without green tea. Initiation was induced by a single dose (200 mg/kg) of diethylnitrosamine at week 4 and 0.02% (w/w) 2-acetylaminofluorene was supplied in the diets. The control group had free access to water for 13 weeks (CTR13). Tea infusion was provided from the beginning of the experiment for 13 weeks (PRE13) or from the post-initiation stage until week 13 (POST13). Three other groups (CTR24, PRE24 and POST24) were added to examine the longer-term effects (24 weeks) with the same experimental design. The percentage area of liver sections that were positive for hepatic placental glutathione S-transferase (GST-P), which was used as a marker of preneoplastic lesions, was smaller in PRE13 ($20.2{\pm}5.0%$, $mean{\pm}SD$) and POST13 ($26.0{\pm}4.8%$) than in CTR13 ($33.2{\pm}5.8%$, p<0.05). Over the longer period, the GST-P lesions were significantly smaller for both PRE24 and POST24 ($21.6{\pm}8.5%$ and $22.2{\pm}4.0%$, respectively) than for CTR24 ($28.6{\pm}5.1%$, p<0.05), but there was no significant difference between PRE24 and POST24. The liver content of thiobarbituric acid reactive substances was significantly lower in the tea groups than in the controls (p<0.05). However, no significant differences were observed among groups of GST activity. The results show that tea consumption exhibits a stronger short-term initiation-inhibiting ability in liver carcinogenesis, but over a longer period, the preventive effects of green tea ingestion do not differ in post- and pre-initiation.

• 동아시아식생활학회지
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• 제21권3호
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• pp.367-374
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• 2011

The purpose of this study was to determine the optimum condition for producing tea leaf Jeung-pyun that does not contain added parched tea leafs (0, 0.5, 1, 1.5, and 2%) while producing Jeung-pyun that has a variety of functional ingredients and to investigate the possibility of making practical application of tea leafs. Moisture contents were 56 ~66% and there were no significant differences among the samples. The pH of Jeung-pyun samples was 5.65~5.74. The L-value decreased as the amount of added tea leaf increased, and the a-value was low in the group made with added tea leafs. The b-value was high in the 1% added group and had a tendency to increase vs the control group as amount of added tea leaf increased. In the groups with added tea leaf the volume was evaluated as being higher in the order of 1>1.5>2%. The specific volume of the group with added tea leaf was evaluated as being higher in the order of 1>1.5>2%. Sensory characteristics of the group with added tea leaf were evaluated as being high. For characteristics of cell uniformity, rice wine flavor, and sweetness, the control group was evaluated as being high, and for characteristics of color, moistness, and softness the 1% added group was evaluated as high. Astringency was evaluated as being high in the 2% added group. Texture profile analysis was conducted after samples were maintained in an incubator at $20^{\circ}C$ for 0, 1, 3, 5, and 7 days. Characteristics for hardness, gumminess, chewiness tended to increase with longer periods of storage. Characteristics for cohesiveness, springiness tended to decrease as the storage period increased. As determined by this study, addition of 1% tea leaf was the most favorable method for making use of tea leafs the production of Jeung-pyun and a potentiality for the use of tea leafs in food was discorvered.

• Food Science and Biotechnology
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• 제27권6호
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• pp.1843-1856
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• 2018

Tea is one of the most frequently consumed drinks due to its favourite taste and the health benefit. Tea is produced by several processes and drying is very important step to develop the flavour and destroys the enzymes in tea. However, during drying tea, polycyclic aromatic hydrocarbons some of which are carcinogen and genotoxin are naturally produced. The risk of PAHs by drinking tea was characterized by determining contents of 4 PAHs in tea. 4 PAHs including Benz(a)anthracene (BaA), Chrysene (CHR), Benzo(b)fluoranthene (BbF) and Benzo(a)pyrene (BaP) were investigated by GC-MS in total 468 tea products, which were contaminated up to $4.63ng\;g^{-1}$. Mate tea was the most highly contaminated by BaA, CHR, BbF and BaP and followed by Solomon's seal and Chrysanthemum. The Margin of Exposures calculated by the concentration of BaA, CHR, BbF and BaP and consumption amount of tea were higher than 10,000, and the risk of PAHs in tea were low concern to public health.

• 동아시아식생활학회지
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• 제10권5호
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• pp.411-418
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• 2000

The purpose of this study was to investigate the sensory and mechanical characteristics of mayonnaise containing various levels of green tea powder The highest viscosity of mayonnaise was obtained at the green tea powder concentration of 0.5% The emulsion, stability was increased with the addition of green tea powder. In the sensory evaluation, overall acceptabilty appeared to be the highest when 0.1% of green tea powder was added. There was a significant difference between the samples (P<.05) In terms of change in color, the values of L, a, b, and ΔE decreased as the amount of green tea powder increased. In the measurement of the texture, the hardness of mayonnaise was highest in the control of green tea powder, and the springiness appeared to be higher in the mayonnaise with 0.1% of green tea powder. The odor acceptabilty in the sensory evaluation showed a negative correlation with the values of gumminess in the mechanical characteristics. The subjective parameters that affect overall quality on sensory evaluation were determined by, and they were odor acceptabilty, after taste, oily taste, sour odor. sweet taste. egg odor, color acceptabilty, and salty taste. These results showed that mayonnaise made with 0.1% green tea powder, salad oil 474.5ml. egg golk 85g, sugar l0g, salt 7g, and vinegar 23m1 with the addition of 0.6g green tea powder was the most effective compared with other treatments.

• 한국식품조리과학회지
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• 제18권4호
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• pp.407-412
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• 2002

녹차를 첨가한 마요네즈의 신화아정성을 조사하기 위하며 대두유, 난황, 식초, 설탕, 식염과 녹차의 분말을 0~0.5% 첨가하여 마요네즈를 제조한 후, 5$^{\circ}C$, 15$^{\circ}C$, $25^{\circ}C$에 13주간 저장하면서 과산화물가의 변화를 조사한 결과는 다음과 같다. 1. 마요네즈를 5$^{\circ}C$, 15$^{\circ}C$, $25^{\circ}C$에 13주간 저장했을 때, 대조구의 과산화물가는 각각 28, 63.5, 144.4 meq/kg 으로 저장온도가 높을수록 산화가 촉진되었다. 2. 녹차의 마요네즈에 대한 항산화작용은 녹차의 첨가농도에 비례하였으나 저장온도가 높을수록 그 효과는 감소하였다. 3. 녹차의 첨가는 마요네즈 유지 산화에 대한 유도기간을 연장하는 효과가 있었으며 녹차 분말을 0.5% 첨가했을 때 전 저장 온도에서 유의적인 유도기간의 연장효과를 볼 수 있었다(p<0.05). 4. 마요네즈에 0.1%의 녹차를 첨가했을 때의 상대적 항산화효과는 5, 15, $25^{\circ}C$에서 각각 226%, 188%, 143%였으며 마요네즈에 첨가하는 녹차 농도에 비례하여 증가하였다. 이러한 결과는 녹차를 마요네즈의 산화를 방지할수 있는 천연 항산화제로서 이용할 수 있는 충분한 가치가 있는 것으로 판단된다.

• 한국식품조리과학회지
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• 제33권1호
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• pp.37-44
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• 2017

Purpose: The purpose of this study was to simplify the traditional manufacturing method of Jeungpyun by developing a new process for Jeungpyun preparation using meringue and to also investigate the quality characteristics of Jeungpyun made with green tea powder. Methods: The Jeungpyun was manufactured as 4 sample preparations (Jeungpyun: J; Jeungpyun+0.5% green tea: J+0.5% GT; Jeungpyun+1% green tea: J+1% GT; and Jeungpyun+1.5% green tea: J+1.5% GT) through mixing rice flour, meringue, green tea powder (0-1.5%), dry yeast, water, and milk, steaming for 4 min at $180^{\circ}C$ and 3 min at $220^{\circ}C$, and then standing for 1 hr at room temperature. The quality characteristics of Jeungpyun were evaluated based on physicochemical properties, total mold, texture analysis, and sensory evaluation. Results: The pH of Jeungpyun batter was significantly lower in J+1.0% GT and J+1.5% GT than J. The specific gravity, weight, volume, and specific volume of J+0.5% GT and J+1% GT was not significantly different, as compared to J. In color, L value decreased and a and b value increased based on the increase of green tea powder. The antifungal activity was the highest in J+1.5% GT, followed by J+1.0% GT, J+0.5% GT, and J, in order. Samples with added green tea powder showed decreased hardness, as compared with J; its effect was significant in J+1.0% GT and J+1.5% GT after storage for 1 day. In sensory evaluation, the color of Jeungpyun was darkened by the addition of green tea powder. The egg smell and hardness significantly decreased by addition of green tea powder. Based on quantitative description analyses, overall acceptability was the highest in J+1% GT. Conclusion: Therefore, 1% green tea powder was the optimal amount for preparing Jeungpyun with meringue. For simplification of the traditional manufacturing method, Jeungpyun could be produced with meringue and green tea powder, which has potent physiological activities.

• Integrative Medicine Research
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• 제3권1호
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• pp.25-33
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• 2014

Background: Green tea contains numerous polyphenols, which have health-promoting effects. The purpose of this study was to evaluate the effect of tannase-converted green tea extract (TGE) formulation on the physical stability and activities of skin-related enzymes. Methods: Physical stability was evaluated by measuring the pH, precipitation, and colors at $25{\pm}2^{\circ}C$ /ambient humidity and at $40{\pm}2^{\circ}C$ \70%${\pm}$5% relative humidity for 4 months. Activities of collagenase, elastase, and tyrosinase as skin-related enzymes were assessed on TGE formulation. Results: The concentrations of epigallocatechin-3-gallate and epicatechin-3-gallate in green tea extract were greatly decreased to the extent of negligible level when treated with tannase. The formulation containing 5% tannase-converted green tea extract showed relatively stable pH, precipitation, and color features for 16 weeks. When TGE was added to the formulation, there was a significant increase in the inhibition of elastase and tyrosinase activities (p<0.05) compared with the formulation containing 5% normal green tea extract. Conclusion: The TGE could be used in cosmetics as skin antiwrinkling or depigmenting agent.

• 한국식품영양과학회지
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• 제28권3호
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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.

• 한국식생활문화학회지
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• 제20권1호
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• pp.103-112
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• 2005

The objective of this study was to clarify the effect of addition of green tea powder(0%, 2%, 4%, 6%, 8%) to Yackwa on quality and preservation. Addition of 4% green tea powder turned out to give positive effect on expansion. In test of physical characters, addition of green tea powder had a tendency to lower hardness, cohesiveness, springness and gumminess but to enhance brittleness. Considering the rancidity of oil within Yackwa, addition of green tea powder tended to show lower acid value and peroxide value than non-added treatment but its difference was slight. At the sensory test, surface color, bitterness and green tea flavor were strong but sweet and savory taste weak when green team powder was added(p<0.05). Overall quality appeared to have improved to 5.55 points which is compared to non-addition when the powder was added 4%(p<0.05). In conclusion, 4% addition of green tea powder would be the usefull method to enhance preference and quality of Yackwa.