• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.774-783
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• 2013

This study investigated the quality characteristics of boiled pork with different amounts (0.5, 1, 1.5, or 2%) of green tea, oolong tea and black tea extracts. Characteristics measured included approximate composition, water holding capacity (WHC), hardness, pH, Hunter's color value, total aerobic bacterial counts, volatile basic nitrogen (VBN), 2-thiobarbituric acid reactive substances (TBARS), and sensory qualities. Green tea approximately contained 3.4%, 31.8%, 5.5%, and 57.7% of moisture, crude protein, crude ash, and carbohydrate, respectively. There were no significant differences with the type of tea. However, the crude fat content of green tea, oolong tea, and black tea were 1.6%, 1.0%, and 0.9%, respectively. Green tea had the highest content of crude fat (p<0.05). Boiled pork approximately contained 55.1%, 38.6%, 5.2% and 0.9% moisture, crude protein, crude fat and crude ash, respectively. The WHC of boiled pork, with tea extract added, significantly increased and there were no significant differences according to the type of tea. The hardness of boiled pork significantly increased as the amount of tea extract added increased (p<0.05). The pH of the boiled pork was not significantly different after storage for one day, but significantly decreased in control groups and boiled pork with 0.5% of any tea extract added during storage. However, in boiled pork with 1%, 1.5%, or 2% of any tea extract added, pH was not significantly different during storage. The Hunter's L and b values decreased in all boiled pork. The Hunter's a-values also decreased in boiled pork with green and black tea extract added, but increased in boiled pork with oolong tea extract added. In boiled pork with tea extract added, total aerobic bacterial counts significantly decreased as the amount of tea extract added increased during storage (p<0.05). The VBN values significantly increased during storage in all groups. TBARS values were significantly lower in boiled pork with green tea extract added, oolong tea added (at concentrations of 1%, 1.5%, or 2%), and black tea extract added compared to control groups on the first day. The sensory evaluation results showed that the color, flavor, and overall acceptance of boiled pork containing 1% of oolong or black tea extracts had the highest scores but there were no significant differences. However, taste scores were significantly different (p<0.05). These results indicate that boiled pork has improved quality characteristics with 1% of oolong or black tea extracts added.

• The Korean Journal of Food And Nutrition
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• v.24 no.1
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• pp.28-36
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• 2011

To investigate the protective effect of omija(Schizandra chinensis Baillon) tea extracts against the aluminum toxicity, Sprague-Dawley rats($100{\pm}10\;g$) were divided into 6 groups consisting of a control group, a 3% Schizandra chinensis Baillon tea plus extract group, a 1,000 and 2,000 ppm aluminum group, and a 1,000 and 2,000 ppm aluminum plus 3% Schizandra chinensis Baillon tea plus extract group. The rats administered aluminum were given 1,000 and 2,000 ppm of $Al_2(SO_4)_3$ dissolved in distilled water. The aluminum content in tissues from rats administered aluminum was lower than in the tissues of rats of administered aluminum plus 3% Schizandra chinensis Baillon tea in the water extract. Aspartate aminotransferase (AST) and alanine aminotransferase(ALT) levels were increased in the aluminum group and lower in the group receiving a 3% extract of Schizandra chinensis Baillon tea. Lactate dehydrogenase(LDHase) was lower in the group receiving a 3% extract of Schizandra chinensis Baillon tea plus aluminum than in the aluminum group. Cholinesterase(ChEase) was higher in the 3% Schizandra chinensis Baillon tea-aluminum group than in the aluminum group. Plasma levels of renin were increased in the aluminum group, compared to the group receiving 3% Schizandra chinensis Baillon tea plus aluminum. Plasma levels of aldosterone were increased in the aluminum group compared with the 3% Schizandra chinensis Baillon tea plus aluminum group. These results suggest that the group receiving Schizandra chinensis Baillon tea in water extract had a lowered level of aluminum accumulation, and it is believed that the Schizandra chinensis Baillon tea plus water had some protective effects against aluminum toxicity when administered in rats, but the mechanism of these effects remains obscure.

• Textile Coloration and Finishing
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• v.18 no.6 s.91
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• pp.80-87
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• 2006

Nowadays, interests of ultraviolet(UV) protection increased, since the UV dosage on the earth surface has increased over years. Overdose of UV can cause various skin, eye, and even DNA damages. Therefore, it is need to develop a proper mean to protect human skin and eye from UV radiation. In this study, the UV protective effect of green tea extract dyed fabrics with various fiber types were examined. Green tea has an active moiety called 'catechin' having benzene rings in its structure, which would exert a proper UV protective property. Green tea dyed fabrics showed the increase in UV protection, and silk showed the highest increase in UV protection (from 52.2% to 84.5% in UV-A, from 66.1% to 90% in UV-B). The order of UV-A protection increase is silk, wool, nylon and acrylic, PET, and cotton. The order of UV-B protection increase is silk nylon, wool, acrylic, cotton, and PET. In case of silk and nylon, the UV protection property gradually increased as the concentration of green tea extract increased. As a result, it was proven that green tea extract dyeing can improve UV protection property of dyed fabrics in environment-friendly and biocompatible manners.

• Korean journal of food and cookery science
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• v.21 no.3 s.87
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• pp.346-353
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• 2005

CThis study used HPLC to analyze the contents of 7 kinds of catechins, 4 kinds of theaflavins, and 2 kinds of methylxanthines in the following 6 kinds of commercial Korean tea: 2 green, 2 black, 1 jasmine and loolong. The following ranges in the 13 tea components of the 6 samples by ethanol extract were evaluated in mg/g: (-)-epigallocatechin, 0(black tea and jasmine tea) to 14.19(green tea); (-)-catechin 0; (+)-epicatechin, 0.62(bran rice-green tea) to 2.91(black tea); (-)-epigallocatechin gallate, 4.59(black tea) to 43.96(jasmine tea); (-)-gallocatechin gallate, 0.58(black tea) to 5.80(jasmine tea); (-)-epicatechin gallate, 5.63(bran rice-ueen tea) to 48.06(jasmine tea): (-)-catechin gallate, 0.26(black tea): theaflavif 0 to 3.66(black tea): theaflavin-3-gallate, 0 to 6.94(black tea): theaflavin-3'-gallate, 0 to 4.01(black tea); theaflavin-3,3-digallte, 0 to 10.25(black tea); caffeine, 4.60(bran rice-peen tea) to 26.44(black tea); and theobromine, 0.10(bran rice-green tea) to 1.81(jasmine tea). The contents of all components were lower by water extract than by ethanol extract. Therefore, total catechin (100.55, 45.88 mg/g) and theobromine (1.81, 0.86 mg/g) contents in jasmine tea, and theaflavin content (24.88, 1.36 mg/g) in black tea by ethanol and water extract were the highest. Caffeine content was the highest in black tea(96.48 mg/g) for the ethanol extract, and in jasmine tea (12.38 mg/g) for the water extract.

• Biomedical Science Letters
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• v.28 no.1
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• pp.50-57
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• 2022

In this study, we tried to examine the possibility of developing a dental product such as tooth decay prevention and oral hygiene by manufacturing a natural polymer film for oral use. Natural polymer films were prepared from shark byproduct extract (SBE) and gellan gum (GG). As an antibacterial substance, the antibacterial activity of green tea extract against tooth decay-causing bacteria was measured. An film was prepared by adding green tea extract to the composition of SBE and GG. The mechanical, solubility, moisture content and antibacterial function of the prepared film were investigated in detail. Also, the incorporation of GTE into the SBE/GG film improved the physical performance of the film. Increasing the content of GTE improved the antioxidant and antibacterial properties of the film. Formulation of antimicrobial SBE/GG film containing green tea extract was established and these results evidently showed potential for cavity prevention products application.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.6
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• pp.752-758
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• 2005

This study examined growth and sensory characteristics of soybean sprout cultured at $25\pm1^{\circ}C$ for 4 days with distilled water(control) and green tea extract(0.03 and $0.05\%$). Initial germination rate was higher when soaking in green-tea extract than in the control. The proper concentration of green-tea extract was $0.03\%$. The growth of soybean sprout in $0.05\%$ green-tea extract was better than the control for the hypocotyl thickness and mot hair. Soybean sprout grown with green-tea extract were better than that with control inappearance, flavor, texture and over-all acceptabilitty.

• The Korean Journal of Community Living Science
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• v.16 no.1
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• pp.59-64
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• 2005

This study is to find out effects of hot water soluble extract from green tea, one of the Korean favorites, on the calcium metabolism and bone strength in body. To do so, calcium, phosphate, creatinine concentration and ALP activity in blood and the content of calcium and ash in the organ, the length, weight, strength in bone were measured. In addition, to find the calcium metabolism, the level of calcium intake, excretion, retention were measured. Twenty male Sprague-Dawley rats were divided into two groups and isoloated soy protein was provided as the source of protein and CaCO₃ was provided as the source of calcium. 0.5% hot water soluble extract from green tea was provided to the green tea groups and for the control group deionized water was provided. The results are as follows ; 1. There is no difference between the experimental groups in diet intake, weight gain, and the feed intake. 2. Feed efficiency ratio was low in the group which hot water soluble extract from green tea was provided. 3. There is no difference between groups the level of calcium, phosphorus, creatinine and ALP activity in serum. 4. There is no difference between groups weight, contents of ash and calcium in kidney and liver. 5. There is no difference between groups in calcium intake, absorption, excretion, and retention. 6. There is no difference between groups weight, length and strength in bone. In summary, when hot water soluble extract from green tea was provided with the amount of 150-200mg, which is taken when people generally drink as favorite tea, weight gain was reduced due to the decrease of feed efficiency ratio. However, it did not affect the availability of calcium in body at all. Thus, even if a big quantity of green tea powder or solid of hot green tea extract is not provided, the quantity obtained when people drink green tea lowers the feed efficiency ratio without reducing availability of calcium in body.

• Journal of Nutrition and Health
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• v.32 no.4
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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.

• Current Research on Agriculture and Life Sciences
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• v.31 no.2
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• pp.101-107
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• 2013

This study was undertaken to determine free radical scavenging capacity and oxidative DNA damage protecting activity of methanol extract of red tea stem. The extract was subjected to assess their antioxidant potential using various in vitro systems such as $DPPH^{\bullet}$, $ABTS^{{\bullet}+}$, super oxide and nitric oxide free radicals and it exhibited $IC_{50}$ values of $68.88{\pm}1.1$, $12.08{\pm}0.65$, $404.38{\pm}1.6$, $93.6{\pm}2.7{\mu}g/mL$ respectively. Red tea extract also showed ferric reducing ability (FRAP) with 2606.85 mmol Fe (II)/g of extract. Furthermore, Methanol extract of red tea stem showed significant DNA damage protecting activity in concentration dependent manner against $H_2O_2+UV$ induced photolysis on pUC19 plasmid DNA. Results of this study showed that the methanol extract of Red Tea stem has strong antioxidant potential along oxidative DNA damage protecting capacity that would be the significant sources of natural antioxidants, which might be helpful in preventing the progress of various oxidative stress generated diseases. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidant.

• 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.