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Rahman, M., I. A. Jahan, S. Ahmed, K. S. Ahmed, M. Roy, W. Zzaman, and I. Ahmad. "Bioactive compounds and antioxidant activity of black and green tea available in Bangladesh." Food Research 5, no. 3 (May 16, 2021): 107–11. http://dx.doi.org/10.26656/fr.2017.5(3).491.
Testo completoAbstract (sommario):
People in Bangladesh are traditionally used to consume mainly black tea. However, some tea manufacturing companies are now producing green tea, though in a small scale. To create new knowledge as well as awareness about the consumption of green tea, the present study was carried out to compare the black and green tea available in Bangladesh based on their bioactive compounds and antioxidant activity. A total of eight brands of black tea and two brands of green tea were bought from the supermarkets. Total phenolics, total tannin, total flavonoids, and caffeine content were measured as bioactive compounds, and antioxidant activity was evaluated by using two different methods such as DPPH (1,1- diphenyl-2-picrylhydrazyl) radical-scavenging activity and ABTS+ radical scavenging activity of methanol extracts of black and green tea. Every bioactive compound in black and green tea was found to be significantly different (P < 0.05). The total phenolic content, on average, was measured at 242.46 mg GAE/g dry extract and 763.41 mg GAE/ g dry extract in black and green tea, respectively. Black tea contained 6.47 mg TAE/g dry extract tannin, whereas green tea had much more tannin content, 14.51 mg TAE/g dry extract, which is more than double in amount. On the other hand, the total flavonoid content was almost double in black tea (61.82 mg QE/g dry extract) compared to green tea (31.85 mg QE/g dry extract). Antioxidant activities were determined at different concentrations of tea samples. At every concentration, green tea presented higher ABTS+ and DPPH radical scavenging activity than black tea. The highest percentage of inhibition was observed at 20 ppm both in black and green tea, finding 98.50 % and 99.07 % inhibition, respectively. Overall, significantly (P < 0.05) higher amount of phenolic compounds as well as antioxidant activity were observed in green tea.
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&NA;. "Green tea." Reactions Weekly &NA;, no. 1163 (August 2007): 14. http://dx.doi.org/10.2165/00128415-200711630-00043.
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&NA;. "Green tea." Reactions Weekly &NA;, no. 1132 (December 2006): 10–11. http://dx.doi.org/10.2165/00128415-200611320-00028.
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&NA;. "Green tea." Reactions Weekly &NA;, no. 1135 (January 2007): 17. http://dx.doi.org/10.2165/00128415-200711350-00065.
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&NA;. "Green tea." Reactions Weekly &NA;, no. 1269 (September 2009): 22. http://dx.doi.org/10.2165/00128415-200912690-00061.
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&NA;. "Green tea." Reactions Weekly &NA;, no. 1249 (April 2009): 23. http://dx.doi.org/10.2165/00128415-200912490-00074.
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&NA;. "Green tea." Reactions Weekly &NA;, no. 1308 (July 2010): 20. http://dx.doi.org/10.2165/00128415-201013080-00055.
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Hutcheon, Deborah A., and Jane Ziegler. "Green Tea." Topics in Clinical Nutrition 29, no. 3 (2014): 268–77. http://dx.doi.org/10.1097/tin.0000000000000004.
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Hume, Anne L. "Green tea." Pharmacy Today 25, no. 9 (September 2019): 16. http://dx.doi.org/10.1016/j.ptdy.2019.08.007.
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Guslandi, Mario. "Green tea." Alimentary Pharmacology & Therapeutics 19, no. 10 (April 29, 2004): 1135. http://dx.doi.org/10.1111/j.1365-2036.2004.01953.x.
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Song, H. S. "Antioxidant effects of green tea extracts on lipid oxidation of half-dried eels." Food Research 5, no. 2 (February 21, 2021): 62–66. http://dx.doi.org/10.26656/fr.2017.5(2).620.
Testo completoAbstract (sommario):
In order to explore the change of lipid oxidation of half-dried eels treated with green tea extracts and stored frozen, acid values, peroxide values, carbonyl values, and TBA values were measured. The eels were placed into the plastic bag and soaked for 1 hr in the solution mixed with distilled water and green tea extracts, and also vacuumed and stored frozen at –18 ∼ –20°C for 9 months after being dried with a hot-air blower for 15 hrs at 35°C (Aw 90-91). The control consisted of eels prepared in the same way without any pretreatment. At the end of the 1st month, 3rd month, 6th month, and 9th month, eel oil obtained from the samples were tested for its lipid oxidation. The activity of green tea extracts 1 mL was very similar to Vitamin C 500 μM 0.8 mL. The acid values, peroxide values, carbonyl values, and TBA values of eels treated with green tea extracts were lower than those of the control during 9 months of frozen storage (p<0.05). While the acid values and peroxide values of the control and eels treated with green tea extracts highly increased after the first month of frozen storage, the TBA values increased greatly on the third month of frozen storage. Compared to the control, the pre-application of green tea extracts to half-dried eels meaningfully prevented the generation of TBA compound during the frozen storage (p<0.01). In conclusion, pre-application of green tea extracts was effective in delaying early-stage peracid inducement and preventing the generation of secondary oxidation compounds, such as carbonyl compound and TBA compound, in the course of the drying and frozen storage
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Record, Ian R., Jennifer K. McInerney, and Ivor E. Dreosti. "Black tea, green tea, and tea polyphenols." Biological Trace Element Research 53, no. 1-3 (June 1996): 27–43. http://dx.doi.org/10.1007/bf02784542.
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Li, Yong, Xunhua Zheng, Xiaoqing Fu, and Yanzheng Wu. "Is green tea still ‘green’?" Geo: Geography and Environment 3, no. 2 (July 2016): e00021. http://dx.doi.org/10.1002/geo2.21.
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Susilowati, Agustina, Qarriy ‘Aina Urfiyya, Andi Wijaya, Reksi Sundu, and Risa Supriningrum. "Perbandingan Efek Antihipertensi Ekstrak Etanol White Tea, Yellow Tea, Black Dragon Tea dan Green Tea." Media Farmasi 20, no. 1 (April 20, 2024): 101–9. http://dx.doi.org/10.32382/mf.v20i1.236.
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Comparison Of Antihypertension Effects Of White Tea, Yellow Tea, Black Dragon Tea And Green Tea Ethanol Extracts In Indonesia, hypertension is still a significant health issue. Every year, Indonesia sees a rise in the prevalence of hypertension. Green tea, black dragon tea, white tea, and yellow tea all contain flavonoid antioxidants that may be used to treat hypertension by acting through the antioxidant route. The comparison of the antihypertensive effects of various ethanol extracts of white tea, yellow tea, blackdragon tea, and premium green tea (Camellia sinensis L.) is the main goal of this study. Pretest-Posttest Control Group Design research is this kind of experimental study. White tea, yellow tea, black dragon tea, and premium green tea (Camellia sinensis L.) were all subjected to antihypertensive tests using various ethanol extracts. Thirty Wistar rats were placed into six groups for the antihypertension test, each group comprising are group I (CMC. Na 1%), Group II (Captopril 2.25 mg/kgW), Groups III, IV, V and VI were the treatment groups. which consists of administering ethanol extracts of White Tea, Yellow Tea, Black Dragon Tea and Green Tea Premium at a dose of 500 mg/kgW. Blood pressure checks were carried out 3 times, namely before induction (TD I), after induction (TD II), and after being given the test solution (TD III). The results of the blood measurements then calculate the antihypertensive activity. In this study, it was discovered that captopril had a 40.0% antihypertensive action, compared to 33.3% for white tea ethanol extract, 37.2% for yellow tea, 37.7% for black dragon tea, and 38.0% for green tea. The results of this study indicate that the four ethanol extracts of tea, when administered at a dose of 500 mg/kgBB, can have an antihypertensive effect. However, only yellow tea, black dragon tea, and green tea are not substantially different from captopril (p>0.05). Hipertensi masih menjadi suatu masalah kesehatan yang cukup besar di Indonesia. Prevalensi hipertensi di Indonesia terus meningkat setiap tahunnya. White tea, yellow tea, black dragon tea dan green tea mengandung senyawa flavonoid sebagai antioksidan yang dapat berpotensi sebagai antihipertensi dengan melalui jalur antioksidan. Tujuan dari penelitian ini yaitu mengetahui perbandingan efek antihipertensi berbagai ekstrak etanol white tea, yellow tea, blackdragon tea dan green tea premium (Camellia sinensis L.). Jenis penelitian ini yaitu penelitian eksperimental Pretest-Posttest Control Group Design. Uji antihipertensi berbagai ekstrak etanol berbagai produk teh yaitu white tea, yellow tea, black dragon tea dan green tea premium (Camellia sinensis L.). Pada uji antihipertensi, 30 ekor tikus galur wistar di bagi menjadi 6 kelompok yang terdiri dari kelompok I (CMC. Na 1%), Kelompok II (Captopril 2,25 mg/kgBB), Kelompok III, IV, V dan VI merupakan kelompok perlakuan yang terdiri dari pemberian ekstrak etanol White Tea, Yellow Tea, Black Dragon Tea dan Green Tea Premium dengan dosis 500 mg/kgBB. Pengecekan tekanan darah dilakukan sebanyak 3 kali yaitu pada sebelum penginduksian (TD I), setelah penginduksian (TD II), dan setelah diberikan larutan uji (TD III). Hasil Pengukuran darah tersebut kemudian dihitung aktivitas antihipertensinya. Pada penelitian ini dapat diperoleh data bahwa aktivitas antihipertensi Captopril 40,0%, ekstrak etanol white tea 33,3%, yellow tea 37,2%, black dragon tea 37,7% dan green tea 38,0%. Melalui penelitian ini dapat disimpulkan bahwa keempat ekstrak etanol teh tersebut dengan dosis 500mg/kgBB dapat berefek sebagai antihipertensi, namun hanya yellow tea, black dragon tea dan green tea yang tidak berbeda bermakna (p>0,05) dibandingkan dengan captopril.
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Stoddart, Alison. "Green tea therapy." Nature Materials 13, no. 11 (October 24, 2014): 998. http://dx.doi.org/10.1038/nmat4128.
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Muir, Maya. "(Green) Tea Time." Alternative and Complementary Therapies 4, no. 1 (February 1998): 43–47. http://dx.doi.org/10.1089/act.1998.4.43.
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Kumar, Nagi B. "Green Tea Polyphenols." Evidence-Based Integrative Medicine 2, no. 1 (2005): 13–18. http://dx.doi.org/10.2165/01197065-200502010-00004.
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Ross, Stephanie Maxine. "Green Tea Chings." Holistic Nursing Practice 21, no. 5 (September 2007): 280–82. http://dx.doi.org/10.1097/01.hnp.0000287991.47838.94.
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Naumovski, Nenad, Alexandra Foscolou, Nathan M. D’Cunha, Stefanos Tyrovolas, Christina Chrysohoou, Labros S. Sidossis, Loukianos Rallidis, et al. "The Association between Green and Black Tea Consumption on Successful Aging: A Combined Analysis of the ATTICA and MEDiterranean ISlands (MEDIS) Epidemiological Studies." Molecules 24, no. 10 (May 15, 2019): 1862. http://dx.doi.org/10.3390/molecules24101862.
Testo completoAbstract (sommario):
Tea is one of the most-widely consumed beverages in the world with a number of different beneficial health effects, mainly ascribed to the polyphenolic content of the tea catechins. The aim of this study was to examine the consumption of green, black, or no tea, in relation to the previously validated successful ageing index (SAI; higher values “healthier” ageing) in a combined analysis of adults aged >50 years old from the ATTICA (n = 1128 adults from Athens, Greece metropolitan area) and the MEDiterranean Islands Study (MEDIS) (n = 2221 adults from various Greek island and Mani) studies. After adjusting for age, sex, smoking, and coffee consumption, green tea was positively associated with SAI (b ± SE: 0.225 ± 0.055, p < 0.001), while black tea was negatively associated with SAI (unstandardized b coefficient ± Standard error: −0.807 ± 0.054, p < 0.001). Green tea (vs black tea) consumption, had higher odds of a SAI of over 3.58 out of 10 (OR: 1.77, 95% CI: 1.38–2.28). Green tea consumption was also associated with higher levels of physical activity (p < 0.001) and reduced likelihood of hypertension (p = 0.006) compared with black tea. Two possible mechanisms are that green tea possesses high levels of catechins such as (−)-epigallocatechin 3-gallate and l-theanine compared with black tea. Therefore, the present analysis supports both the role of green tea constituents in successful ageing, as well as its role as an important component of an overall healthy diet in adults aged 50 years and over from these two epidemiological studies.
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Zhou, Pinqian, Mengjuan Chen, Qiang Bao, Hua Wang, Yuanjiang Wang, and Haiping Fu. "The Effect of Intercropping with Different Leguminous Green Manures on the Soil Environment and Tea Quality in Tea Plantations." Microorganisms 12, no. 8 (August 21, 2024): 1721. http://dx.doi.org/10.3390/microorganisms12081721.
Testo completoAbstract (sommario):
Intercropping with green manure is a soil-sustainable cultivation practice that has demonstrated positive impacts on tea growth and the soil environment in tea plantations. Nevertheless, research examining the effect of leguminous green manure varieties in tea plantations is scarce. This study aimed to analyze the tea quality and soil environment components in response to intercropping with three distinct leguminous green manures, Cassia sophera cv. Chafei 1 (CF), Sesbania cannabina (Retz.) Pers. (SC), and Chamaecrista rotundifolia (Pers.) Greene (CR), with 70% chemical fertilizer, and compare them to non-intercropped green manures with 100% chemical fertilizer (CK) in tea plantations. The findings indicated that intercropping with SC increased the amino acids content of tea leaves, the soil organic carbon (SOC), the soil acid phosphatase (ACP), the soil acid protease (ACPT), and the bacterial diversity compared to the CK treatment. Intercropping with CR improved the ACP activity and bacterial diversity while intercropping with CF improved the polyphenols. Proteobacteria, Acidobacteria, Actinomycetes, and Firmicutes were identified as the dominant bacterial taxa in tea plantations with intercropped green manure. A strong positive correlation was indicated between the SOC contents and the amino acids content in tea leaves after intercropping. A canonical correspondence analysis indicated significant associations between the ACP and the urease activity, and between the ACP and ACPT, and both were closely linked to SC. This finding provides an explanation that intercropping with SC may positively affect tea quality by influencing the SOC content, the soil enzyme activity, and the soil bacterial diversity. Green manure intercropping may replace part of chemical fertilizers, improve the soil environment in tea gardens, and enhance the quality of tea. These findings offer a theoretical reference for selecting leguminous green manure and advancing the sustainable development of tea plantations.
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HUI, KEE XIAO, and SITI RAIHANAH SHAFIE. "ADDITION OF MILK ENHANCED THE TOTAL PHENOLIC CONTENT AND ANTIOXIDANT ACTIVITY OF Camellia sinensis (GREEN TEA) BEVERAGES." Malaysian Applied Biology 50, no. 3 (December 31, 2021): 95–104. http://dx.doi.org/10.55230/mabjournal.v50i3.2011.
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The study was aimed to determine the effects of adding milk, sugar and sweeteners to the total phenolic content and antioxidant activity of Camellia Sinensis (green tea) powder. Six green tea samples were brewed in cold water and whisked: Green tea powder (G), green tea powder with sugar (GS), green tea powder with aspartame (GA), green tea powder with milk (GM), green tea powder with milk and sugar (GMS) and green tea powder with milk and aspartame (GMA). The total phenolic content of green tea powder samples was evaluated by using Folin-Ciocalteu assay while α,α-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays were used to measure the antioxidant activity. Results showed that milk addition significantly enhanced by 59.84% of total phenolic content and also increased 26.3% (DPPH) and 42.35% (FRAP) of antioxidant activity of green tea powder, as compared to green tea samples without milk (p<0.05). Strong and positive correlations were found between the total phenolic content and antioxidant activity of green tea powder by using DPPH (r=0.990) and FRAP assays (r=0.997). In conclusion, it might be beneficial when milk is added to green tea as it could help to increase its antioxidant properties.
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Auralia, Muthia, Bambang Sumanto, and Irene Kartika Eka Wijayanti. "POLA KONSUMSI DAN KOMPONEN YANG DIPERTIMBANGKAN OLEH KONSUMEN TEH HITAM DAN TEH HIJAU DI KECAMATAN PURWOKERTO SELATAN." SEPA: Jurnal Sosial Ekonomi Pertanian dan Agribisnis 20, no. 2 (September 30, 2023): 214. http://dx.doi.org/10.20961/sepa.v20i2.58512.
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<p><em>People consume black tea and green tea with certain characteristics in accordance with their wishes and needs. The rating of the product shows the attitude of the people towards a product as well and also reflects their preferences in spending and consuming a product. The aim of this research is to analyse the characteristics of black tea and green tea consumers, to analyse green tea and black tea consumption patterns, and to analyse the components that consideration the preferences of black tea and green tea consumers. Research was held in Southern Purwokerto Sub-district, started from February until March 2020. The number of samples for each black tea and green tea consumers are 50 respondents taken by using multistage random sampling. The analysis which is used is Descriptive Analysis and Factor Analysis. The results show that characteristics of black tea and green tea consumers are women in various range of age. Additionally, married consumers buy black tea and green tea to be consumed together with their family. Perspective of consumption patterns black tea and green tea once a day in the morning breakfast for black tea and in other activities for green tea. The consumption number for family is an average of 50g/months. There are three main components that form preferences on green tea, those are: personality from the tea, identity, and the image of the product. On the other hand, main components that form preferences on black tea are two, those are: image, and identity product.</em></p>
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D. S.G. G. C. Swarnathilake and Don Chandana Abeysinghe. "Improving the quality and the taste of green tea ice cream by identifying suitable cultivar, agronomic practices and processing techniques of Assamica tea grown in Sri Lanka." World Journal of Advanced Research and Reviews 8, no. 1 (October 30, 2020): 062–68. http://dx.doi.org/10.30574/wjarr.2020.8.1.0354.
Testo completoAbstract (sommario):
The objectives of this study were to find the most suitable tea cultivar, shading effect and best tea processing technique for production of green tea powder with low astringency and amount of green tea addition to produce ice cream with best flavor and medicinal values. Green tea powder was manufactured using five different cultivars i.e. TRI 2023, TRI 2026, TRI 2027, TRI 4042 and TRI 4047 grown under shaded and un-shaded conditions with three processing techniques namely; steaming, pan firing and freeze drying and green tea ice cream was prepared using processed green tea powder. To reveal the health benefits of green tea powder and green tea ice cream, total phenolic content (TPC) , total flavonoid content (TFC) and Total antioxidant capacity (TAC) were checked by using modified folin-ciocalteu method , colorimetric method and ferric reducing antioxidant power (FRAP) assay respectively. The best quality green tea in terms of colour and flavour can be produced from tea leaves of TRI 4047 cultivar which was cultivated under shaded conditions with freeze drying processing technique. In terms of colour and flavour, 15 g of green tea added for ice cream mixture (500 mL of milk, 125 mL of whipping cream and 150 g of sugar) is the most suitable amount to add for green tea ice cream preparation. Significantly, higher TAC, TPC and TFC in green tea ice cream when compared to normal ice cream (without green tea powder) indicating the importance of consuming value added green tea ice cream as a healthy food.
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Maheswari, C., R. Venkatnarayanan, P. Babu, and C. S. Kandasamy. "Green Tea (Cardiac Tea) vs Java Tea (Kidney Tea): A Review." Research Journal of Pharmacy and Technology 8, no. 1 (2015): 94. http://dx.doi.org/10.5958/0974-360x.2015.00018.9.
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Dabaladeniya, Sudilikara Gedara Gayathri Chathurika Swarnathilake, and Chandana Abeysinghe Don. "Improving the quality and the taste of green tea ice cream by identifying suitable cultivar, agronomic practices and processing techniques of Assamica tea grown in Sri Lanka." World Journal of Advanced Research and Reviews 8, no. 1 (October 30, 2020): 062–68. https://doi.org/10.5281/zenodo.4318045.
Testo completoAbstract (sommario):
The objectives of this study were to find the most suitable tea cultivar, shading effect and best tea processing technique for production of green tea powder with low astringency and amount of green tea addition to produce ice cream with best flavor and medicinal values. Green tea powder was manufactured using five different cultivars <em>i.e. </em>TRI 2023, TRI 2026, TRI 2027, TRI 4042 and TRI 4047 grown under shaded and un-shaded conditions with three processing techniques namely; steaming, pan firing and freeze drying and green tea ice cream was prepared using processed green tea powder. To reveal the health benefits of green tea powder and green tea ice cream, total phenolic content (TPC) , total flavonoid content (TFC) and Total antioxidant capacity (TAC) were checked by using modified folin-ciocalteu method , colorimetric method and ferric reducing antioxidant power (FRAP) assay respectively. The best quality green tea in terms of colour and flavour can be produced from tea leaves of TRI 4047 cultivar which was cultivated under shaded conditions with freeze drying processing technique. In terms of colour and flavour, 15 g of green tea added for ice cream mixture (500 mL of milk, 125 mL of whipping cream and 150 g of sugar) is the most suitable amount to add for green tea ice cream preparation. Significantly, higher TAC, TPC and TFC in green tea ice cream when compared to normal ice cream (without green tea powder) indicating the importance of consuming value added green tea ice cream as a healthy food.
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Jakubczyk, Karolina, Łukasz Łopusiewicz, Joanna Kika, Katarzyna Janda-Milczarek, and Karolina Skonieczna-Żydecka. "Fermented Tea as a Food with Functional Value—Its Microbiological Profile, Antioxidant Potential and Phytochemical Composition." Foods 13, no. 1 (December 21, 2023): 50. http://dx.doi.org/10.3390/foods13010050.
Testo completoAbstract (sommario):
Kombucha is a fermented tea drink produced by a symbiotic culture of bacteria and yeast, known as SCOBY. Its base has traditionally been black tea, which has been recognized for its health-promoting properties, particularly its antioxidant activity based on its high content of pol-yphenolic compounds. A number of previous studies have demonstrated the equally favourable biochemical and phytochemical composition of green tea. The aim of this study was to analyse and compare the basic biochemical composition, microbiological composition and antioxidant properties of black and green tea-based Kombucha. The green tea-based Kombucha showed a quantitatively more abundant microbial composition (Lactic Acid Bacteria, Acetobacter sp., Yeast), a higher reducing potential (FRAP—4326.58 Fe(II)µM/L) and a higher content of total polyphenols (23.84 mg GAE/100 mL, reducing sugars (3212.00 mg/100 mL) as well as free amino acids (849.00 mg GLY/mL). Kombucha made from black tea, on the other hand, showed a higher anti-oxidant potential (1.17 Trolox (mM) TEAC), neutralising the DPPH radical at 94.33% and ABTS at 97.74%. It also had a higher level of acetic acid (0.08 g/100 mL). Green tea kombucha had a higher scavenging capacity of 90.6% for superoxide radical (O2−) and 69.28% for hydroxyl radical (·OH) than black tea kombucha. In the present study, both kombucha drinks tested were shown to be source of potent antioxidants. In addition, green tea, as a kombucha base, has proven to be as beneficial a raw material that will provide full nutritional and health-promoting values as traditional kombucha.
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Jung, Yun-Jung, So-Hyoung Jung, and Hyun-Ju Jo. "Recognition of the Characteristics Related to Green Tea and Beverage Consumption in Adult Males by Body Mass Index." Korean Tea Society 28, no. 3 (September 30, 2022): 39–47. http://dx.doi.org/10.29225/jkts.2022.28.3.39.
Testo completoAbstract (sommario):
This study sought to investigate the characteristics related to the consumption of green tea and beverages by adult males according to their body mass index. The characteristics examined included preference, taste, image, and perception of health efficacy according to the type of beverage consumed. Further, the variations in the characteristics related to beverage consumption according to the body mass index of the subjects were compared.
 The characteristics were assessed using a self-administered questionnaire rated on a five-point Likert scale. Adult males who usually consume green tea frequently had the highest preference scores for green tea. They also had a high recognition score for the premise that green tea helps to maintain health and assists in weight management.
 Participants who did not consume green tea had significantly lower preference, taste, and health efficacy scores than those who consumed green tea frequently (3∼4 times/week). The taste scores of green tea segregated according to the degree of obesity were significantly higher in the normal weight group than in the obese group. The health efficacy score of green tea and beverages was positively correlated with age and green tea intake. In conclusion, the normal weight group had a greater preference for the taste of green tea than the obese group. In addition, the higher the score on the preference and taste of green tea and the higher the perception that green tea helped improve health, the higher the consumption of green tea.
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Mello, Lucilene Dornelles, and Tiele Garcia Tunes. "INFLUENCE OF PERMANGANATE INDEX IN THE PARAMETERS AS TOTAL PHENOL CONTENT AND TOTAL ANTIOXIDANT ACTIVITY OF EXTRACTS OF CAMELLIA SINENSIS." International Journal of Pharmacy and Pharmaceutical Sciences 9, no. 8 (August 1, 2017): 110. http://dx.doi.org/10.22159/ijpps.2017v9i8.19270.
Testo completoAbstract (sommario):
Objective: This study estimated the Permangante Index (IKMnO4) and evaluated its correlation with parameters as total phenols (FT) and total antioxidant activity (TAA) of commercial teas of Camellia sinensis, fermented, unfermented and blended with other plants.Methods: The aqueous extracts were prepared from commercial samples of green and black teas, green tea blended with lemon (Camellia sinensis with Citrus limonium), green tea blended with mint (Camellia sinensis with Mentha piperita), green tea blended with peach (Camellia sinensis with Prunus persica) and green tea blended with orange (Camellia sinensis with Citrus sinensis). The Permangante index was determined by titrating the tea extract with potassium permanganate solution according to AOAC method (AOAC, 1980) with modifications. The concentration of phenols in the extracts was determined by spectrophotometry according to the standard procedure of Folin-Ciocalteau. The antioxidant activity of the extracts was evaluated using the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. All the determinations were performed in triplicate, and the results presented as mean ± standard deviation (SD). The data were evaluated by univariate statistical analysis (ANOVA), F-test and mean test (Tukey´s test) for comparative results. Pearson’s correlation was used to measure the degree of linear correlation and the quantitative variables were from a normal population.Results: The results for Permanganate Index show a variation ranged from 0.40 to 0.80 mEq/l. The ANOVA analysis to IKMnO4 shown there is significant statistically difference at the 5% probability level (p < 0.05) between the types of tea as well as the amount of herb used to prepare the infusion. Therefore, it was observed that there significant contrast between tea extracts, the mixture of different plants in blended extracts as well as the tea manufacture process affect the polyphenols tannins content influencing the permanganate index parameter. Studies correlation shown strong correlations (r > 0.7) among the parameters. For the Camellia sinensis extracts the high correlations between IKMnO4 and TAA; FT and TAA demonstrates the suitability of the permanganate index in the evaluation of antioxidant activity.Conclusion: The results suggest that the Permanganate Index could be used for quality control of tea as an additional parameter.
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Putri, Fika Melinda, Susi Susi, and Desy Purnama Sari. "Pengaruh Berkumur Dengan Larutan Teh Hijau dan Teh Hitam Terhadap pH Saliva." Andalas Dental Journal 7, no. 1 (June 1, 2019): 1–12. http://dx.doi.org/10.25077/adj.v7i1.129.
Testo completoAbstract (sommario):
The prevalence of caries in Indonesia has increased by 53.53% from 2013 to 2018. Low salivary pH (potential of Hydrogen) is one of the main causes of dental caries. Acid as metabolic product of oral microorganism can decrease the salivary pH. The purpose of this paper is to determine the effect of gargling with green and black tea solutions on salivary pH. The increasing of salivary pH linear to salivary secretion. Gargling with green tea or black tea is one of the ways that can increase salivary secretion and pH by provides a mechanical and chemical stimulus to the oral cavity. Green tea and black tea contain polyphenols (catechins) which can increase salivary pH. Conclusion is gargling with green tea and black tea solutions can add salivary pH. Gargling with green tea is more effective to increase salivary pH than black tea. Green tea has a higher catechins content than black tea, in order to anti-cariogenic and anti-bacterial properties are more common in green tea.
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Reich, Eike, Anne Schibli, Valeria Widmer, Ruth Jorns, Evelyn Wolfram, and Alison DeBatt. "HPTLC Methods for Identification of Green Tea and Green Tea Extract." Journal of Liquid Chromatography & Related Technologies 29, no. 14 (August 2006): 2141–51. http://dx.doi.org/10.1080/15512160600760293.
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Zhao, Tiantian, Chao Li, Shuai Wang, and Xinqiang Song. "Green Tea (Camellia sinensis): A Review of Its Phytochemistry, Pharmacology, and Toxicology." Molecules 27, no. 12 (June 18, 2022): 3909. http://dx.doi.org/10.3390/molecules27123909.
Testo completoAbstract (sommario):
Objectives Green tea (Camellia sinensis) is a kind of unfermented tea that retains the natural substance in fresh leaves to a great extent. It is regarded as the second most popular drink in the world besides water. In this paper, the phytochemistry, pharmacology, and toxicology of green tea are reviewed systematically and comprehensively. Key findings Green tea has been demonstrated to be good for human health. Nowadays, multiple pharmacologically active components have been isolated and identified from green tea, including tea polyphenols, alkaloids, amino acids, polysaccharides, and volatile components. Recent studies have demonstrated that green tea shows versatile pharmacological activities, such as antioxidant, anticancer, hypoglycemic, antibacterial, antiviral, and neuroprotective. Studies on the toxic effects of green tea extract and its main ingredients have also raised concerns including hepatotoxicity and DNA damage. Summary Green tea can be used to assist the treatment of diabetes, Alzheimer’s disease, oral cancer, and dermatitis. Consequently, green tea has shown promising practical prospects in health care and disease prevention.
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Jayathilaka, U. G. M. D., G. A. A. R. Perera, A. M. G. N. Rathnayake, and K. G. B. A. Samarasinghe. "Potential of Utilizing Corn Silk (<em>Stigma maydis</em>), Thebu Leaves (<em>Costus speciosus</em>), Green and Purple Guava (<em>Psidium guajava</em>) Leaves in Formulating Green Tea and Black Tea Blends." Journal of Agricultural Sciences – Sri Lanka 20, no. 1 (January 15, 2025): 38–47. https://doi.org/10.4038/jas.v20i1.10223.
Testo completoAbstract (sommario):
Purpose: Underutilized plant materials such as corn silk (Stigma maydis), guava leaves (Psidium guajava), and ‘thebu’ leaves (Costus speciosus) are rich sources of various phytochemicals with potential health benefits. This study was carried out to investigate the potential of developing green tea and black tea blends by incorporating corn silk, green and purple guava leaves, and ‘thebu’ leaves.Research Method: Five green tea and black tea blends were prepared using steamed and dried ‘thebu’ leaves, corn silk, and green and purple guava leaves. Sensory properties of the samples were evaluated. Antioxidant activity (AOA) and total polyphenol (TPP), total flavonoid (TF), ash and crude fiber contents of the samples were determined.Findings: The selected green tea blend consisted of 50% green tea, 16.7% corn silk, 16.7% ‘thebu’ leaves and 16.7% green guava leaves whereas the selected black tea blend consisted of 50% black tea, 12.5% corn silk, 12.5% ‘thebu’ leaves and 25% purple guava leaves. Comparable TPP contents (gallic acid equivalent %) were found in green tea blends (22.51±0.93) and black tea blends (21.78±0.11). Antioxidant activity (percentage inhibition) of green and black tea blends (85.93±0.44 and 87.38±1.17 respectively) were significantly higher than that of green tea (81.58±0.92) and black tea (81.43±0.88).Research Limitations: The optimal processing conditions for preserving the properties of selected materials are crucial in formulating herbal tea blends, yet they remain to be established.Originality/ Value: Corn silk, green and purple guava, and ’thebu’ leaves hold great potential for formulating tea blends with improved physicochemical, therapeutic, and sensory properties
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Prawira-Atmaja, Mukhammad Iqbal, Sugeng Haryanto, Hilman Maulana, Shabri Shabri, and Dr Dadan Rohdiana. "Karakteritik sifat alir bubuk teh hijau yang diproses dengan metode penepung berbeda." Jurnal Sains Teh dan Kina 21, no. 2 (December 15, 2019): 85–95. http://dx.doi.org/10.22302/pptk.jur.jptk.v21i2.147.
Testo completoAbstract (sommario):
Recently, the public interest in green tea powder is increasing. Green tea powder is produced through the process stage: withering in hot steam, drying, and reducing size. The size reduction process on green tea powder is an important step because it will affect the characteristics of the powder flow properties. This study aims to determine the flow properties of green tea powder processed by different milling method. The milling method used are disc milling (DM) and stone milling (SM). Green tea powder was analyzed including moisture content, particle size distribution using dynamic laser scattering method, determined of bulk density (ρb), and tapped density (ρtap) to find out the Carr Index (CI) and Hausner Ratio (Hr). In addition, the lightness of color and shape and morphology of green tea powder were observed with SEM. The results showed that green tea powder produced from different milling methods have a Carr Index of 15 with “Good” flow properties. DM method produced darker green tea powder with L value (lightness) 49.91 and larger particle size (D50: 38.6 µm) compared with green tea powder produced by the SM method. Determination of flow properties of green tea powder can be applied for the utilization and development of food products and pharmaceutical products based on green tea powder.
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Wu, Feifei, Bo Lin, Jing Chen, Fengjin Zheng, Xiaochun Fang, Lianfeng Luo, Haisheng Chen, Krishan K. Verma, and Ganlin Chen. "Characteristic Aroma Screening among Green Tea Varieties and Electronic Sensory Evaluation of Green Tea Wine." Fermentation 10, no. 9 (August 29, 2024): 449. http://dx.doi.org/10.3390/fermentation10090449.
Testo completoAbstract (sommario):
Green tea is a non-fermented tea with flavor and polyphenols. Aroma is one of the important quality indicators of tea. Fermented green tea wine can solve the problem of low-grade tea, which has more bitterness and less aroma. In this study, Camellia sinensis var. pubilimba Hung T. Chang (Kaishan white tea 2) was screened by orthogonal partial least squares-discriminant analysis (OPLS-DA) to benzyl alcohol and phenethyl alcohol presenting a fruity aroma, dimethyl sulfide presenting a green tea aroma, and rich tea polyphenols with contents of 2.08, 2.43, 12.26 and 3.72%, respectively. The optimal fermentation conditions for green tea wine were determined univariately as 1.5% yeast addition, 30 °Brix initial sugar, and fermentation temperature of 25 °C. The electronic sensory assessment showed that the saltiness, richness and umami were more prominent in green tea wine, while the response values of bitterness, astringency and aftertaste-A were lower. The order of aroma contribution can be seen as W1S > W5S > W2S > W2W > W1W > W3S > W6S. Kaisan white tea 2 gives green tea wine a clear tea aroma. This study provides better technical and theoretical strategies for the comprehensive quality assessment and control of fermented green tea wine quality.
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Song, Dae-Kyu. "Green tea: a tea or a remedy?" Integrative Medicine Research 3, no. 1 (March 2014): 1–3. http://dx.doi.org/10.1016/j.imr.2014.01.002.
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Hu, Wenwen, Gege Wang, Shunxian Lin, Zhijun Liu, Peng Wang, Jiayu Li, Qi Zhang, and Haibin He. "Digital Evaluation of Aroma Intensity and Odor Characteristics of Tea with Different Types—Based on OAV-Splitting Method." Foods 11, no. 15 (July 25, 2022): 2204. http://dx.doi.org/10.3390/foods11152204.
Testo completoAbstract (sommario):
Aroma is one of the most important quality indicators of tea. However, this evaluation method is a subjective one. In this study, the volatiles of tea with 5 types were determined by headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography mass spectrometry (GC-MS). The aroma intensity and odor characteristics of teas were comparatively analyzed based on the OAV-splitting method. The results showed that OAV were green tea (492.02), red tea (471.88), oolong tea (302.74), white tea (68.10), and dark tea (55.98). The odor index I(o) indicated that green tea was strong-flavor tea with highlight green accompanied by fruity, woody and fatty odors; oolong tea was strong-flavor tea with fruity and fatty accompanied by woody, floral and green odors; red tea was strong-flavor tea with highlight fruity accompanied by woody, green and floral odors; white tea was a light-flavor tea with floral, woody and green odors; and dark tea was light-flavor tea with woody and floral notes accompanied by fatty and green odors. These results fitted perfectly with the people’s consensus on these teas, and proved that the OAV-splitting method is feasible to evaluate the aroma intensity and odor characteristics of tea aroma. We suggest that the digital evaluation of tea aroma can facilitate people’s communication.
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Luo, Qiong, Jia-Rong Zhang, Hua-Bin Li, Ding-Tao Wu, Fang Geng, Harold Corke, Xin-Lin Wei, and Ren-You Gan. "Green Extraction of Antioxidant Polyphenols from Green Tea (Camellia sinensis)." Antioxidants 9, no. 9 (August 25, 2020): 785. http://dx.doi.org/10.3390/antiox9090785.
Testo completoAbstract (sommario):
In this study, the feasibility of improving the extraction yield of green tea antioxidant polyphenols by the combination of ultrasound-assisted extraction (UAE) and deep eutectic solvents (DESs) was investigated. Choline chloride (ChCl)-glycerol was selected as the best DES among 12 ChCl-based DESs to extract tea antioxidant polyphenols. Subsequently, the influences of extraction parameters on total phenolic content (TPC) values were investigated, and liquid/solid ratio, ultrasonic power, and ultrasonic time were optimized based on the response surface methodology. The optimal extraction conditions were a liquid to solid ratio of 36:1 (mL/g), ultrasonic power of 461.5 W, and ultrasonic time of 21 min, with the highest TPC value of 243 ± 7 mg gallic acid equivalent (mg GAE)/g dry weight (DW), which was 13% higher than that before optimization. In addition, under the optimal extraction conditions, tea polyphenolic extract exhibited higher antioxidant activity compared with conventional extraction methods. Four major catechins in the green tea extracts, including (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-epicatechin gallate (ECG) and (−)-epigallocatechin gallate (EGCG) were identified and quantified by high-performance liquid chromatography. In addition, scanning electron microscopy (SEM) analysis revealed that UAE-DES effectively disrupted the green tea leaf cells, thereby improving tea polyphenol yield. In summary, UAE-DES is an ideal green extraction method for the extraction of tea antioxidant polyphenols.
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Nafisah, Umi, Aptika Oktaviana Trisna Dewi, and Anes Aisna Hana Lulu. "Determination of Catechin Content in Green and Black Tea (Camellia sinensis L.) by UV-Vis Spectrophotometric Method." Jurnal Sains dan Kesehatan 6, no. 1 (February 29, 2024): 24–30. http://dx.doi.org/10.25026/jsk.v6i1.2166.
Testo completoAbstract (sommario):
Tea is one of the most commonly consumed beverages around the world. The chemical compounds contained in tea have a good effect on health because they contain polyphenolic compounds, catechins. This study examined the catechin compound content of black tea and green tea from Karanganyar (A) and Malang (B). This research aims to determine the differences in catechin levels in black and green tea types in Malang, East Java, and Karanganyar, Central Java plantations. The research method used was experimental. Identification of catechin content was done using UV-Vis Spectrophotometry method. Tea is extracted by brewing, 4 grams of green tea is brewed using distilled water for 6 minutes, while 5.6 grams of black tea is brewed using distilled water for 10 minutes with the comparison used is pure catechin solution. The results obtained for green tea Karanganyar (A) had a catechin content of 3.61±0.083%, green tea Malang (B) had a level of 2.97±0.037%, black tea Karanganyar (A) had a level of 3.14±0.065%, and black tea Malang (B) had a level of 1.60±0.009%. It is concluded that the catechin content of green tea is higher than black tea, and of the two samples, the high catechin content comes from Karanganyar (A). Keywords: catechins, green tea, black tea, malang, karanganyar
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Sudjatini, Sudjatini. "OPTIMASI EKSTRAKSI DAN PENENTUAN KANDUNGAN KATEKIN DALAM TEH HIJAU (Camellia sinensis) MENGGUNAKAN METODA HPLC." AGROTECH : JURNAL ILMIAH TEKNOLOGI PERTANIAN 2, no. 1 (February 5, 2019): 43–49. http://dx.doi.org/10.37631/agrotech.v2i1.8.
Testo completoAbstract (sommario):
This research was designed to determine the optimum period extraction time for catechin green tea using boiling water and ethyl acetate as a solubilizing agent, whereas the composition and the content of catechin green tea were measured using High Performance Liquid Chromatography (HPLC). A single factor experiment design was used. The period extraction time of green tea using boiling water and ethyl acetate were 5, 20, 35 and 60 minutes. The proportion of green tea at the extraction process was 1:15 (weight/volume). The extraction process using boiling water was done twice to get the maximum extracted catechin yield. The extracted catechin of green tea were, therefore, compared with epi-catechin as standard solution. The research’s results show that the optimum period for extraction time of green tea using boiling water and ethyl acetate were 35 and 20 minutes, respectively. The extracted green tea using boiling water was 41.39 % of its dry weight, and those extracted green tea contained catechin as high as 60.62-61.78 %. Catechin compound in green tea residues extracted using ethyl acetate was 5.31 % from 58.35 % the total green tea residues. The composition of catechin in the first boiling water extraction, the second boiling water extraction and pressure extraction consisted of epigallocatechin (EGC), epigallocatechin-gallat (EGCG), epicatechin (EC) and epicatechin-gallat (ECG). ECG was only found in green tea residue extracted using ethyl acetate. The total catechin compound in green tea extracted using boiling water and ethyl acetate was 27.73 % of dry weight, consisted of EGC, EGCG, EC and ECG were 14.74, 1.73, 8,35 and 2.91 % of green tea dry weight, respectively
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Srimanothip, Anjaly, and Phakkharawat Sittiprapaporn. "Electroencephalographical investigation of drinking green tea to the human brain." Asian Journal of Medical Sciences 11, no. 1 (January 1, 2020): 33–36. http://dx.doi.org/10.3126/ajms.v11i1.26530.
Testo completoAbstract (sommario):
Background: Nowadays green tea has become one of the most popular drinks all over the world. Evidences suggest that green tea become second most consumer following regular drinking water. Green tea contains Theanine, an amino acid primarily found in green tea and black tea. The content is generally found 1-2% of dried tea or around 60 milligrams per 200 milliliters of tea drink. In particular, this substance is found in the form of L-theanine that can be absorbed to the blood system and then to the brain within 30 minutes, which causes relaxation and reducing stress.
 Aims and Objective: The objective was to examine the effect of green tea consumption on electroencephalographic (EEG) activities.
 Materials and Methods: This study was an experimental design. The participants were twelve Thai healthy, aged between 21-55 years old. During the experiment, all participants were asked to drink green tea every 10 minutes.
 Results: The influence to brainwave and attentive process were tested by experimental design. The study indicated that alpha brainwave was shown after drinking green tea. Frequency of alpha brainwave along cumulative drinking of green tea was shown significantly since the 10th minute. However, spectrum of the alpha brainwave changed significantly after drinking green tea, after 30th minutes.
 Conclusion: The benefit of this study was to provide the guideline for planning and campaigning green tea consumption for the purpose of stress reduction resulting in relaxation.
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Pérez-Burillo, Sergio, Beatriz Navajas-Porras, Alicia López-Maldonado, Daniel Hinojosa-Nogueira, Silvia Pastoriza, and José Ángel Rufián-Henares. "Green Tea and Its Relation to Human Gut Microbiome." Molecules 26, no. 13 (June 26, 2021): 3907. http://dx.doi.org/10.3390/molecules26133907.
Testo completoAbstract (sommario):
Green tea can influence the gut microbiota by either stimulating the growth of specific species or by hindering the development of detrimental ones. At the same time, gut bacteria can metabolize green tea compounds and produce smaller bioactive molecules. Accordingly, green tea benefits could be due to beneficial bacteria or to microbial bioactive metabolites. Therefore, the gut microbiota is likely to act as middle man for, at least, some of the green tea benefits on health. Many health promoting effects of green tea seems to be related to the inter-relation between green tea and gut microbiota. Green tea has proven to be able to correct the microbial dysbiosis that appears during several conditions such as obesity or cancer. On the other hand, tea compounds influence the growth of bacterial species involved in inflammatory processes such as the release of LPS or the modulation of IL production; thus, influencing the development of different chronic diseases. There are many studies trying to link either green tea or green tea phenolic compounds to health benefits via gut microbiota. In this review, we tried to summarize the most recent research in the area.
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Nawangsari, Desi. "EVALUASI SEDIAAN MASKER ANTIOKSIDAN DARI EKSTRAK DAUN TEH HIJAU (CAMELLIA SINENSIS)." Viva Medika: Jurnal Kesehatan, Kebidanan dan Keperawatan 10, no. 2 (January 7, 2019): 119–28. http://dx.doi.org/10.35960/vm.v10i2.452.
Testo completoAbstract (sommario):
Abstract
 Green tea (Camellia sinensis L.) has the main efficacy as an antioxidant and contains polyphenol compounds in green tea leaves with the main component of polyphenol fraction namely Epigallocatechin-3-gallate (EGCG) which has strong activity to prevent free radicals that cause premature aging. Research has been carried out on the formulation of maskantioxidant preparations containing green tea leaf extract. The study begins with testing the antioxidant activity of ethanol extract of green tea leaves with a free radical reduction method of 1,1-diphenyl-2-picrylhydrazyl using visible spectrophotometry. Testing of antioxidant activity showed that the ethanol extract of green tea leaves gave an IC50 value of 3.17µg / mL. Formulations of gel masks made were F0 (base without active substances), F1 (base + concentration of ethanol extract of green tea leaves for IC50 (0,000317%)), F2 (base + concentration of ethanol extract of green tea leaves for 50xIC50 (0, 0158%)), F3 (base + concentration of ethanol extract of green tea leaves for 100xIC50 (0.0317%)), F4 (base + concentration of ethanol extract of green tea leaves for IC50), F5 (base + concentration of ethanol extract of green tea leaves worth IC50), F6 (base + concentration of ethanol extract of green tea leaves for IC50. Evaluation of gel mask preparations include, organoleptic examination and homogeneity,
 pH, viscosity, dry time of preparation and testing of antioxidant stability. F2 provides better and higher free radical reduction activity than products on the market. F4, F5, F6 shows an increase in free radical reduction activity.
 
 Keywords: Green tea leaves (Camellia sinensis L.), DPPh, IC50 gel mask.
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Nawangsari, Desi. "UJI AKTIVITAS SEDIAAN MASKER ANTIOKSIDAN DARI EKSTRAK DAUN TEH HIJAU (CAMELLIA SINENSIS)." Viva Medika: Jurnal Kesehatan, Kebidanan dan Keperawatan 10, no. 2 (January 7, 2019): 129–34. http://dx.doi.org/10.35960/vm.v10i2.453.
Testo completoAbstract (sommario):
Abstract
 
 Green tea (Camellia sinensis L.) has the main efficacy as an antioxidant and contains polyphenol compounds in green tea leaves with the main component of polyphenol fraction namely Epigallocatechin-3-gallate (EGCG) which has strong activity to prevent free radicals that cause premature aging. Research has been carried out on the formulation of maskantioxidant preparations containing green tea leaf extract. The study begins with testing the antioxidant activity of ethanol extract of green tea leaves with a free radical reduction method of 1,1-diphenyl-2-picrylhydrazyl using visible spectrophotometry. Testing of antioxidant activity showed that the ethanol extract of green tea leaves gave an IC50 value of 3.17µg / mL. Formulations of gel masks made were F0 (base without active substances), F1 (base + concentration of ethanol extract of green tea leaves for IC50 (0,000317%)), F2 (base + concentration of ethanol extract of green tea leaves for 50xIC50 (0, 0158%)), F3 (base + concentration of ethanol extract of green tea leaves for 100xIC50 (0.0317%)), F4 (base + concentration of ethanol extract of green tea leaves for IC50), F5 (base + concentration of ethanol extract of green tea leaves worth IC50), F6 (base + concentration of ethanol extract of green tea leaves for IC50. Evaluation of gel mask preparations include, organoleptic examination and homogeneity,
 pH, viscosity, dry time of preparation and testing of antioxidant stability. F2 provides better and higher free radical reduction activity than products on the market. F4, F5, F6 shows an increase in free radical reduction activity.
 
 Keywords: Green tea leaves (Camellia sinensis L.), DPPh, IC50 gel mask.
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Zhang, Rong Xiang, Wei Zhang, Xiao Hui Zhao, Yan Wei Zhang, Guang Li, and Xiao Wei Li. "The Identification of Green Tea Based on Feature Extraction." Advanced Materials Research 718-720 (July 2013): 580–85. http://dx.doi.org/10.4028/www.scientific.net/amr.718-720.580.
Testo completoAbstract (sommario):
In order to identify the green tea quickly and accurately, the infrared spectra of teas measured by Fourier transform infrared spectroscopy are analyzed by using informatics method of feature extraction in this work. By comparing the different characteristic bases found by different feature genes of different tea samples, it is concluded that when green tea, yellow tea and white tea are chosen to constitute the standardized spectrum data matrix, and its first and third feature gene are selected to build characteristic basis, the green tea can be visually distinguished and the same samples have a very good aggregation. While when the characteristic basis is built by the first and second feature gene or the second and third feature gene, or the samples which are used to make up of standardized spectrum data matrix are all green tea, the recognition effect of green tea is bad. A linear arbiter of green tea is set up according to neutrality line principle on the above effectively characteristic basis, when all samples are projected onto the characteristic basis it is shown that all the green tea fall on the right of arbiter, and all not green teas are on the left of arbiter, consequently, the green tea can be identified.
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Kaur, Amandeep, Sumaya Farooq, and Amit Sehgal. "A Comparative Study of Antioxidant Potential and Phenolic Content in White (Silver Needle), Green and Black Tea." Current Nutrition & Food Science 15, no. 4 (June 28, 2019): 415–20. http://dx.doi.org/10.2174/1573401313666171016162310.
Testo completoAbstract (sommario):
Background: White, green and black are the major tea types obtained from the same tea plant (Camellia sinensis). The differences in processing result in different types of tea, of which green tea (20%) and black tea (78%) are the most consumed worldwide and also white tea is gaining popularity due to its subtle taste and recent evidences about its health benefits. Silver needle is a sub type of white tea, made purely from buds whereas green tea is procured from leaves that are steamed or panfried, and to produce black tea, the tea leaves are withered, fully oxidized and then dried. Objective: The present study was undertaken to analyze and compare the antioxidant activity and phenolic composition of white (silver needle), green and black teas of same brand. Method: The radical scavenging ability of different tea types was measured using various antioxidant assays. The total phenolic content was also estimated using Folin-Ciocalteu’s method. Results: The white tea (silver needle) demonstrated highest radical scavenging activity followed by green and then black tea in various antioxidant assays performed. The total phenolic content of different types of tea exhibited the following order: white tea (133.30mg/g) > green tea (118.37mg/g) > black tea (101.8mg/g). A strong correlation was observed between the total phenolic content and antioxidant activity of different tea types, the correlation coefficient ranged from 0.87-0.97. Conclusion: White tea (silver needle) manifested highest antioxidant activity followed by green and least in black tea. The pronounced antioxidant ability of WT (silver needle) may be ascribed to the different parts of the plant (unopened buds) and the least processing it undergoes, followed by obtaining green tea and black tea from different parts of the plant (leaves), and variation in degree of processing.
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Nawangsari, Desi. "FORMULASI SEDIAAN MASKER ANTIOKSIDAN DARI EKSTRAK TEH HIJAU (CAMELLIA SINENSIS)." Viva Medika: Jurnal Kesehatan, Kebidanan dan Keperawatan 10, no. 2 (January 7, 2019): 109–18. http://dx.doi.org/10.35960/vm.v10i2.451.
Testo completoAbstract (sommario):
Abstract
 
 Research has been carried out on the formulation of maskantioxidant preparations containing green tea leaf extract. The study begins with testing the antioxidant activity of ethanol extract of green tea leaves with a free radical reduction method of 1,1-diphenyl-2-picrylhydrazyl using visible spectrophotometry. Testing of antioxidant activity showed that the ethanol extract of green tea leaves gave an IC50 value of 3.17µg / mL. Formulations of gel masks made were F0 (base without active substances), F1 (base + concentration of ethanol extract of green tea leaves for IC50 (0,000317%)), F2 (base + concentration of ethanol extract of green tea leaves for 50xIC50 (0, 0158%)), F3 (base + concentration of ethanol extract of green tea leaves for 100xIC50 (0.0317%)), F4 (base + concentration of ethanol extract of green tea leaves for IC50), F5 (base + concentration of ethanol extract of green tea leaves worth IC50), F6 (base + concentration of ethanol extract of green tea leaves for IC50. Evaluation of gel mask preparations include, organoleptic examination and homogeneity,
 pH, viscosity, dry time of preparation and testing of antioxidant stability. F2 provides better and higher free radical reduction activity than products on the market. F4, F5, F6 shows an increase in free radical reduction activity.
 
 Keywords: Green tea leaves (Camellia sinensis L.), DPPh, IC50 gel mask.
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Stoeva, Stanila, Nadezhda Hvarchanova, Kaloyan D. Georgiev, and Maya Radeva-Ilieva. "Green Tea: Antioxidant vs. Pro-Oxidant Activity." Beverages 11, no. 3 (May 1, 2025): 64. https://doi.org/10.3390/beverages11030064.
Testo completoAbstract (sommario):
Green tea is one of the most consumed beverages globally. It is very popular due to its specific taste, energizing effect and some health benefits related mainly to the catechins content. Green tea catechins possess antioxidant, anticancer, anti-inflammatory and antimicrobial activity as well as reduce body weight. One of the major and well-studied effects of green tea catechins is their antioxidant effect. However, long-term administration of high doses of antioxidants may result in a pro-oxidant effect and promote cell damage. Therefore, beneficial effects of green tea are directly related to the administered dose of catechins. But it should be noted that consumption of large quantities of green tea beverages or administration of high doses of green tea catechins does not guarantee health benefits and may even lead to adverse effects. This review provides a comprehensive overview of the current knowledge of the antioxidant and pro-oxidant activity of green tea catechins as well as research gaps that require further investigation. In conclusion, despite green tea antioxidant potential, further research is needed to fully understand the benefits and risks associated with the consumption of green tea beverages as well as green tea catechins in different forms and doses.
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Krishna, Lora Krisina. "ANALISIS KADAR TANIN BERBAGAI JENIS TEH HITAM DAN TEH HIJAU KHAS KOTA PAGARALAM SEBAGAI ANTIOKSIDAN MENGGUNAKAN METODE SPEKTROFOTOMETER UV-VIS." Jurnal Penelitian Farmasi & Herbal 7, no. 2 (May 2, 2025): 1–25. https://doi.org/10.36656/jpfh.v7i2.2186.
Testo completoAbstract (sommario):
The plant known as tea (Camellia sinensis L.) is widely grown in Indonesia. The shoots of young tea leaves are brewed into a health drink. This research was carried out with the aim of determining the tannin content of green tea and black tea as well as their antioxidant activity using the UV-Vis spectrophotometer method. Thick extracts from black tea and green tea from qualitative and quantitative test results showed the presence of tannin compounds with tannin levels in the samples obtained were T1 Black tea (CTC Tea) Slopes of Mount Dempo 0.070, T2 Green tea (PTPN 7) Pagaralam tea typical of South Sumatra 0.061, T3 Green tea (PTPN 7) Gunung Dempo 0.028, T4 Black Tea (CTC Tea) Pucuk Gunung Dempo 0.059, and antioxidant activity was tested using 2,2 diphenyl-1-picrylhydrazyl (DPPH). Black tea and green tea extracts have antioxidant activity with a value of IC50 (Inhibition Concentration 50). T1 has very strong antioxidant activity (13.89%), followed by code T2, the antioxidant activity is also very strong (3.67%), code T3 has very strong antioxidant activity. strong (2.02 %), and T4 code moderate antioxidant activity (6.02 %). Black tea and green tea extracts contain high levels of tannin and have very strong antioxidant activity.
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Modesto, Pamela N., Bertha F. Polegato, Priscila P. dos Santos, Leticia D. V. Grassi, Leticia C. C. Molina, Silmeia G. Z. Bazan, Elenize J. Pereira та ін. "Green Tea (Camellia sinensis) Extract Increased Topoisomerase IIβ, Improved Antioxidant Defense, and Attenuated Cardiac Remodeling in an Acute Doxorubicin Toxicity Model". Oxidative Medicine and Cellular Longevity 2021 (5 травня 2021): 1–10. http://dx.doi.org/10.1155/2021/8898919.
Testo completoAbstract (sommario):
Experimental studies have shown the action of green tea in modulating cardiac remodeling. However, the effects of green tea on the cardiac remodeling process induced by doxorubicin (DOX) are not known. Therefore, this study is aimed at evaluating whether green tea extract could attenuate DOX-induced cardiac remodeling, assessed by cardiac morphological and functional changes and associated with the evaluation of different modulators of cardiac remodeling. The animals were divided into four groups: the control group (C), the green tea group (GT), the DOX group (D), and the DOX and green tea group (DGT). Groups C and GT received intraperitoneal sterile saline injections, D and DGT received intraperitoneal injections of DOX, and GT and DGT were fed chow supplemented with green tea extract for 35 days prior to DOX injection. After forty-eight hours, we performed an echocardiogram and euthanasia and collected the materials for analysis. Green tea attenuated DOX-induced cardiotoxicity by increasing cardiac function and decreasing the concentric remodeling. Treatment with DOX increased oxidative stress in the heart, marked by a higher level of lipid hydroperoxide (LH) and lower levels of antioxidant enzymes. Treatment with green tea increased the antioxidant enzymes’ activity and decreased the production of LH. Green tea extract increased the expression of Top2-β independent of DOX treatment. The activity of ATP synthase, citrate synthase, and complexes I and II decreased with DOX, without the effects of green tea. Both groups that received DOX presented with a lower ratio of P-akt/T-akt and a higher expression of CD45, TNFα, and intermediate MMP-2, without the effects of green tea. In conclusion, green tea attenuated cardiac remodeling induced by DOX and was associated with increasing the expression of Top2-β and lowering oxidative stress. However, energy metabolism and inflammation probably do not receive the benefits induced by green tea in this model.
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Maslov, O. Yu, S. V. Kolisnyk, O. V. Hrechana, and A. H. Serbin. "Study of the qualitative composition and quantitative content of some groups of BAS in dietary supplements with green tea leaf extract." Zaporozhye Medical Journal 23, no. 1 (April 7, 2021): 132–37. http://dx.doi.org/10.14739/2310-1210.2021.1.224932.
Testo completoAbstract (sommario):
Recently, there has been a high demand from the population for dietary supplements that have antioxidant activity. First of all, these are dietary supplements with green tea leaf extract, because green tea contains catechins in a fairly high amount. Nowadays, according to the current legislation of Ukraine the qualitative composition and quantitative content of biologically active substances in dietary supplements are not established, which to a certain extent affects the quality and safety of these products. The aim of the study was to determine the qualitative composition and quantitative content of some groups of BAS in dietary supplements with green tea leaf extract. Materials and methods. Three dietary supplements from different manufacturers “Green Tea Extract”, “Green Tea Extract”, “Green Tea” were chosen for the study. Qualitative analysis was performed by thin layer chromatography, for quantification spectrophotometry in the UV-region was used. Results. The presence of catechins was found in the studied dietary supplements, caffeine was found only in trace amounts. The total content of catechins is 146.80 ± 1.36 mg, 79.00 ± 0.88 mg, 28.00 ± 0.75 mg, and in terms of green tea extract, which is stated in dietary supplements for dietary supplements “Green Tea Extract”, “Green Tea Extract”, “Green Tea”, respectively. Conclusions. Qualitative and quantitative analysis of some groups of BAS of three dietary supplements with green tea leaf extract was performed. It was found that dietary supplements “Green Tea Extract” and “Green Tea” meet the requirements of the US Pharmacopoeia 38 in terms of catechins. Based on the study, it can be concluded that the problem of compliance with dietary supplements is relevant today and requires the introduction of regulatory documentation for the detection and determination of biologically active substances in dietary supplements.