• KSBB Journal
• /
• v.14 no.5
• /
• pp.517-522
• /
• 1999

A green tea used in this experiment was cultivated at Bosung (Chonnam) and purchased from a domestic market. The extract at 5$0^{\circ}C$ water from the powder of green tea partitioned with chloroform and ethyl acetate. The resulting solution was further purified with a chromatographic column (4.6$\times$250 mm, 15${\mu}{\textrm}{m}$, Lichrospher 100RP-18). Finally separation was achieved on a $\mu$-Bondapak $C_18$(3.9$\times$300mm, 10${\mu}{\textrm}{m}$) column. The elution order of the catechin compounds contained in the green tea was EGC(Epigallocatechin, C(catechin), EC(Epicatechin), EGCG(Epigallocatechin Gallate) and ECG(Epicatechin Gallate). From the experimental results the mobile phase for isolating EGCG from the extract consisted of 0.1% acetic acid in water/acetonitrile, 87/13%(v/v). The flow rate of mobile phase was 1.0 $m\ell$/min, and UV wavelength was fixed at 280 nm. 121.3 mg of EGCG, higher than 98% of purity, was obtained from 5 g of dry green tea.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.3
• /
• pp.413-417
• /
• 2003

To evaluate the antimicrobial activity of green tea against putrefactive microorganism in steamed bread, antibacterial activity of green tea extract against well-known strains of spoilage bacteria (Bacillus subtilis ATCC 6633, Bacillus pulmilus KCTC 3348 and Bacillus cereus IFO 12113) and mold (Aspergillus niger KCCM l1239) in bread was determined using the paper disk method. The green tea extract (GTE) showed the inhibition effects on the growth of all the strains of bacteria and mold at 1, 2, 3% levels. The activity of GTE was stable in the wide range of pH (4~9) and temperature (50~20$0^{\circ}C$). When green tea powder (GTP: 1, 3, 5%) was added to steamed bread increase of total bacterial and mold counts declined during storage at 25"C as the levels of GTP increased. By addition of 5% GTP, mold appeared 1 day late extending shelf life of steamed bread compared to control bread without GTP. Therefore, the levels of GTP added to steamed bread could be more than 5% for extended shelf life and wholesomeness of steamed bread.read.

• Korean Journal of Environmental Agriculture
• /
• v.42 no.4
• /
• pp.396-407
• /
• 2023

The golden apple snail (Pomacea canaliculata) has been utilized as a natural and eco-friendly control of weeds in rice paddy fields. However, P. canaliculata can damage other crops. In this study, the effectiveness of plant extracts from various natural sources that are reportedly effective against pests in the control of P. canaliculata was investigated. The four plant extracts were effective against P. canaliculata and ranked in descending order as green tea seed (Camellia sinensis) > root of red spider lily (Lycoris radiata) > leaves of tobacco (Nicotiana tabacum) > root of sophora (Sophora flavescens). The mortality rate of P. canaliculata was increased using 200 to 2000 mg/kg of green tea seed powder. However, shrubby sophora root extract did not significantly increase the mortality rate. The LC₅₀ and LC₉₀ of green tea seed, tobacco leaves, shrubby sophora root, and red spider lily root were 900 and 2800 mg/L, 956 and 2320 mg/L, 2162 and 5325 mg/L, and 512 and 1054 mg/kg, respectively. The LC₅₀ and LC₉₀ of ground powder of C. sinensis, N. tabacum, S. flavescens and L. radiata were 248 and 646 mg/L, 403 and 733 mg/L, 409 and 905 mg/L, and 493 and 1141 mg/L, respectively. The findings indicate the remarkable control potency of green tea seeds against the golden apple snail. An organic material incorporating the four plant powders may help control green apple snail in an ecosystem-friendly manner.

• Food Science and Preservation
• /
• v.16 no.3
• /
• pp.333-341
• /
• 2009

The antioxidant properties of green tea leaves and powder extracts were determined using several tests including estimation of reducing power, DPPH(1,1-diphenyl-2- picrylhydrazyl) radical-scavenging activity, and FRAP(Ferric reducing/antioxidant power) assay. All tests indicated that extracts of green tea powder had higher antioxidant activities than extracts of green tea leaves, and the activities were concentration-dependent. However, each test yielded somewhat different results with respect to storage conditions. The reducing power of green tea leaves was highest at $1,000{\mu}g/mL$, storage at $4^{\circ}C$, and an Aw(water activity) value of 0.23. However, the reducing power of green tea powder, assayed at $1,000{\mu}g/mL$, was high under all storage conditions(with variations in temperature and Aw), and was about 1.5.2-fold greater than that of green tea leaves. Radical-scavenging activity, as assessed by the DPPH assay, increased in a dose-dependent manner over the range $15{\sim}125{\mu}g/mL$. At higher concentrations, activities were $80{\sim}90%$ of maximal were attained. The FRAP activity of green tea extract also increased with rising concentration. Particularly in the case of green tea leaves, antioxidant activity was most greatest with storage at $-20^{\circ}C$ and Aw values of 0.69 and 0.23 when assayed at a concentration of $1,000{\mu}g/mL$. These results indicate that the most important factor during storage of green tea is not the Aw value but rather temperature, and that use of refrigeration($4^{\circ}C$) is preferable to increase or maintain the antioxidant activities of biological components in green tea.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.6
• /
• pp.1580-1584
• /
• 2005

Antioxidative activities of catechin from green tea extracts were examined by the methods of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) electron donating ability, hydroxy scavenging activity and the inhibitory effect on xanthine oxidase activity. The resulted demonstrated the fact that Catechin one (containing Green tea extracts plus catechin 51%) of green tea extracts product showed at 65.5% in electron donating activity on the DPPH. The electron donating ability on the DPPH of Catechin one was increased to 10% than purified catechin. Catechin one showed the activity at 64.5% in scavenging activity using hydroxy radical method. To the Catechin one provided to increase the hydroxy scavenging activity up to 3 fold. Inhibitory effects of the catechin one measured with xanthine oxidase method was 6.5%. Although the antioxidative activity of catechin (98% purified) was lower than that of Catechin one (containing Green tea extracts plus catechin 51%) in same catechin concentrations ($5{\mu}g$, respectively). Therefore, we may suggest that Catechin one can be used as a functional food additive possessing the potent antioxidative activity.

• Korean Journal of Agricultural Science
• /
• v.42 no.4
• /
• pp.407-414
• /
• 2015

To increase antioxidative activity of Chungkukjang, the protective effect of Seoritae Chungkukjang (SC) added with green tea powder against oxidative stress was evaluated under the cellular system using LLC-$PK_1$ cells. The treatment of 3-morpholinosydnonimine showed increase in lipid peroxidation, and decrease in endogenous anti-oxidant enzymes activity and cell viability. The methanol extract of SC inhibited lipid peroxidation by 70.9%, and significantly increased cell viability up to more than 33.2%. In addition, it enhanced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. Particularly, the addition of green tea in SC exerted protective effect against oxidative stress by ONOO- through elevation in activities of SOD and GSH-Px, and inhibition of lipid peroxidation. More addition of green tea showed stronger protective activity. These results suggest that the addition of green tea to SC leads to the increase in the antioxidative effect of Chungkukjang through elevation in antioxidative enzyme activities and protection from lipid peroxidation.

• Preventive Nutrition and Food Science
• /
• v.16 no.2
• /
• pp.104-109
• /
• 2011

Recently, we have demonstrated that green tea extract (GTE) decreases the intestinal absorption of benzo[a]pyrene (BAP), which is an extremely lipophilic food contaminant. The present study was conducted to examine if an enteral infusion of GTE would influence the biliary secretion of BAP and lipids in rats. Female rats were fed an AIN-93G diet with or without (control) GTE at 5 g/kg diet for 4 week. Following the 4-week dietary treatment, rats with bile duct cannula were infused continuously for 8 hr at 3.0 mL/hr via a duodenal catheter with a lipid emulsion containing $4.0\;{\mu}mol$ BAP labeled with $^{14}C$ ($^{14}C$-BAP), $20.7\;{\mu}mol$ cholesterol, $452\;{\mu}mol$ triolein, and $3.1\;{\mu}mol$ ${\alpha}$-tocopherol, and $396.0\;{\mu}mol$ Na-taurocholate with or without 76.1 mg GTE powder in PBS buffer (pH, 6.4). Bile was collected hourly via bile cannula for an 8 hr period. Our results showed that bile flow did not differ between groups. However, the biliary secretion of $^{14}C$-BAP was significantly enhanced by GTE infusion, compared with those infused with the lipid emulsion alone. However, GTE did not affect the biliary outputs of cholesterol, fat, phospholipid and ${\alpha}$-tocopherol. These findings indicate that GTE has a profound stimulatory effect on the biliary excretion of BAP in rats, without affecting other biliary lipids. The mechanism(s) by which GTE enhances the biliary secretion of BAP remains to be investigated.

• Korean Journal of Food Science and Technology
• /
• v.33 no.6
• /
• pp.656-663
• /
• 2001

The most representative nitrosamine derived from nicotine, nitrosamine-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK), has been reported to cause lung cancer in A/J mice. It has been also demonstrated that NNK-induced lung tumorigenesis involves $O^6-methylguanine(O^6MeG)$ formation, leading to $GC\;{\rightarrow}\;AT$ transitional mispairing during DNA replication. Our in vitro experiment, modified from the method of DBA assay, examined the ability of phyto-extract mixture to inhibit the metabolism of nicotine to nitrosamines. The production of nitromorpholine from morpholine was inhibited about 75% at the concentration of 20 mg/mL of phyto-extract mixture, which was lower than vitamine C and green tea powder. NNK, which is a pro-carcinogen in laboratory animals, is hydroxylated primarily in liver and lung by CYP 1A2, 2A6 and 3A4. A critical phase. of NNK activation is its change to an unstable metabolite methyl-diazohydroxide via CYP-mediated ${\alpha}-hydroxylation$; and then it provides a methyl group to the DNA to form DNA adducts which can easily induce mutations. $Aroclor^R$ 1254 was used to induce CYPs in the liver of a Sprague-Dawley rat. The ability of various test samples to inhibit CYPs that participate in NNK activation was evaluated, following the removal of the liver from the rat. Microsomal CYPlA2 catalyzing the conversion of NNK into strong carcinogenic chemicals was inhibited more efficiently by phyto-extract mixture than green tea powder. These results indicate that phyto-extract mixture can be used to reduce $O^6MeG$ DNA adducts for chemoprevention.

• Journal of the Korean Society of Food Culture
• /
• v.6 no.1
• /
• pp.43-54
• /
• 1991

The types and processing characteristics of traditional non-alcoholic beverage and their historical backgrounds were surveyed through the old literatures published from the 8th century to 1940. A total of over 70 different names of beverages were found in the literature. They were classified into 10 groups according to their processing methods and quality characteristics; Sunda (green tea), Yusada (tea analog with/without green tea), Tang (boiled herb extract), Jang (lactic acid fermented rice beverage), Suksu (rice tea), Mium (cereal gruel), Misik (roasted cereal powder), Sikhe (sweet rice beverage saccharified with malt), Sujonggwa (ginger-fruit drink) and Hwachai (fruits drink). In the old literatures, there was non exist clear distinction between Jang, Tang, Chong and Tea. Lactic acid fermented rice beverage seemed to be a common drink in Silla and Koryo periods (AD. 600-1400), but disappeared afterwards and completely forgotten today. Other beverages are maintained until today with almost identical methods of preparation as described in the literatures written in the 18th century.

• Biomolecules & Therapeutics
• /
• v.13 no.2
• /
• pp.107-112
• /
• 2005

Excessive drinking causes 'alcohol hangover' within 8-16 hours. The cause of 'hangover' has not been elucidated exactly until now, but it is reported that it is caused by the creation of blood ethanol and acetaldehyde as ethanol metabolites. In this study vinegar extract of wood (VE) or OC-1, to which the powder extract of green tea leaves extract is added, was administered to the rats 30 minutes before the oral administration of ethanol (3 g/kg) and the blood ethanol and acetaldehyde concentration was measured in order to evaluate the efficacy of the beverage material for detoxification. As a result, the blood ethanol concentration in the group of the VE-1(vinegar crude extract) and VE-2 (double diluted solution) is statistically lower (P,0.05) than the exclusive alcohol administered control group. The blood acetaldehyde concentration of all groups of VE and OC-2, which is the double dilution of OC-1, is statistically low after 7 hours following ethanol administration. Especially, the AUC value of OC-2 group is statistically low compared to the control group. Accordingly, it indicates the conclusion that VE and OC-1, reducing the blood ethanol and acetaldehyde concentration which are two leading factors of 'hangover' after drinking, and worthwhile to be developed as beverage materials to eliminate 'hangover'.