Determination of caffeine content and main catechins contents in green tea (Camellia sinensis L.) using taste sensor technique and multivariate calibration

2010 ◽  
Vol 23 (4) ◽  
pp. 353-358 ◽  
Author(s):  
Quansheng Chen ◽  
Jiewen Zhao ◽  
Zhiming Guo ◽  
Xinyu Wang
Keyword(s):  
Green Tea ◽  
Camellia Sinensis ◽  
Multivariate Calibration ◽  
Caffeine Content ◽  
Sensor Technique ◽  
Taste Sensor

Determination of lemon and carbonate effects on caffeine content of various teas and investigation of daily caffeine intakes / Çeşitli çayların içerdikleri kafein miktarlarına limon ve karbonatın etkisi ve günlük alım miktarlarının incelenmesi

2016 ◽  
Vol 41 (5) ◽  
Author(s):  
Funda Demir ◽  
Azmi Seyhun Kıpçak ◽  
Özgül Dere Özdemir ◽  
Mehmet Burçin Pişkin ◽  
Emek Möröydor Derun
Keyword(s):  
Green Tea ◽  
Camellia Sinensis ◽  
Black Tea ◽  
Daily Maximum ◽  
Caffeine Content ◽  
Tea Infusions ◽  
Health Field

AbstractObjective: Tea (Camellia sinensis), has been used for health field in thousands of years. Caffeine is one of the key component in tea and investigation of caffeine is a popular working subject among the researches. The novelty of this study is not only the determination of the caffeine contents of the teas, but also how addition of lemon and carbonate effects the caffeine contents. Another aim of the study is the investigation of the daily caffeine intakes from teas.Methods: Tea infusions were prepared and caffeine contents were extracted by using chloroform and determined by UV-Vis Spectrophotometer. For lemon and carbonate addition experiments, lemon was added before the caffeine analysis and carbonate was added at the beginning.Results: Maximum caffeine contents from highest to lowest were seen in black, earl grey and green in classic teas; fennel, mint and sage in herbal teas; lemon, apple and rosehip in fruit teas. With lemon addition caffeine contents were increased except green tea and with carbonate addition caffeine contents were decreased except black and fennel tea. Daily caffeine intakes are found between 32.10% (green tea with carbonate) - 77.20% (black tea with lemon), 1.85% (sage tea with carbonate) - 4.05% (fennel tea with lemon) and 2.10% (rosehip with carbonate) - 4.00% (lemon tea with lemon) in classic, herbal and fruit teas, respectively.Conclusion: The significance of this study indicates that herbal and fruit teas contain caffeine, which is assumed zero in literature. The caffeine amount of herbal teas (20.79±0.36-30.68±0.63 ppm) were found barely higher than the fruit teas (22.87±0.54-28.54±0.75 ppm) but daily maximum caffeine intakes were found less than 5%. The daily maximum caffeine intakes were found in the teas as 525.36±2.84-20.79±0.36 ppm, where lemon addition increased to 617.90±3.54-22.97±0.58 ppm and carbonate addition decreased to 488.54±2.05-16.84±0.28 ppm.

scholarly journals Rapid LC-MS/MS Determination of Hesperidin in Fermented Tea Prepared from Unripe Satsuma Mandarin (Citrus unshiu) Fruits and Third-crop Green Tea (Camellia sinensis) Leaves

2020 ◽  
Vol 36 (10) ◽  
pp. 1243-1249 ◽  
Author(s):  
Masashi MIURA ◽  
Mamiko NOGAMI ◽  
Miho SAKAI ◽  
Miwa SATO ◽  
Takeshi YATSUSHIRO
Keyword(s):  
Green Tea ◽  
Camellia Sinensis ◽  
Citrus Unshiu ◽  
Satsuma Mandarin

Full Validation of a Simple Method for Determination of Catechins and Caffeine in Brazilian Green Tea (Camellia sinensis var. assamica) Using HPLC

2007 ◽  
Vol 65 (9-10) ◽  
pp. 607-610 ◽  
Author(s):  
S. T. Saito ◽  
P. E. Fröehlich ◽  
G. Gosmann ◽  
A. M. Bergold
Keyword(s):  
Green Tea ◽  
Camellia Sinensis ◽  
Simple Method

scholarly journals Determination of methylxanthines in tea samples by HPLC method

2019 ◽  
Vol 18 (2) ◽  
pp. 124-132
Author(s):  
Timotej Jankech ◽  
Mária Maliarová ◽  
Nicholas Martinka
Keyword(s):  
Green Tea ◽  
Mobile Phase ◽  
Hplc Method ◽  
Optimum Composition ◽  
Psychoactive Substances ◽  
West Lake ◽  
Caffeine Content ◽  
Peak Areas

Abstract Methylxanthines such as caffeine, theophylline, theobromine are significant and widespread psychoactive substances. We developed the isocratic method with optimum composition of the mobile phase 90 % water: 10 % acetonitrile and confirmed repeatability of retention times and peak areas. The developed HPLC method was applied to determine the content of methylxanthines in selected types of black and green teas available on the market. Of the black teas (tea bags), the highest concentration of theobromine was found in Ceylon tea (18.98 mg.L−1). The highest concentration of caffeine was in a cup of Earl Gray tea (254.09 mg.L−1). Among loose black teas, the highest content of both theobromine and caffeine was found in Pu Erh Superior tea, where the theobromine content was 24.62 mg.L−1 and the caffeine content was 520.67 mg.L−1. Of green powder teas, highest caffeine content (306.46 mg.L−1) was in Shizuoka Matcha Premium and the highest content of theobromine (8.45 mg.L−1) was found in GABA Midori. From the loose green tea, the highest concentration of theobromine (12.85 mg.L−1) was in Lung Ching West Lake. The highest caffeine content (484.85 mg.L−1) was in Gyokuro Shizuoka Premium Tea. In both types of teas the amount of theobromine and caffeine was quantified, but the presence of theophylline was not proven. Data on contents of these metabolites in tea products are highly informative for consumers.

scholarly journals CONCENTRAÇÃO DE CAFEÍNA EM Camellia sinensis

2018 ◽  
Vol 10 (3) ◽  
pp. 09-15
Author(s):  
Daniele Nascimento Silva ◽  
Marielle Flaviane de Carvalho Pimentel ◽  
Daniel Ângelo Macena ◽  
Vinícius Marques Gomes
Keyword(s):  
Green Tea ◽  
Camellia Sinensis ◽  
Black Tea ◽  
Ultraviolet Region ◽  
Physiological Effects ◽  
Chemical Dependence ◽  
White Tea ◽  
Low Concentrations ◽  
The World

Considering that tea is the second most consumed drink in the world it is important not to have excess caffeine in its composition since it causes some physiological effects to humanhealth such as diuretic and chemical dependence. The present project had as objective to compare the results obtained from the determination of caffeine in teas from the Camellia sinensis species with those found in the literature. For that, three samplesof white tea, three of green tea and three of black tea of the same brand were used. The analyzes were performed in triplicates and caffeine determined by spectrophotometry in the ultraviolet region. Black tea had the highest caffeine content (0.106 mg / g), white tea 0.082 mg / g and green tea the lowest (0.067 mg / g). However, the three types of teas have low concentrations when compared to the literature that presented values between 14.3 and 40.0 mg / g of caffeine of tea.

scholarly journals Influence of Seasonal and Yearly Variation on Phenolic Profiles, Caffeine, and Antioxidant Activities of Green Tea (Camellia sinensis (L.) Kuntze) from Azores

2021 ◽  
Vol 11 (16) ◽  
pp. 7439
Author(s):  
Lisete Paiva ◽  
Elisabete Lima ◽  
Madalena Motta ◽  
Massimo Marcone ◽  
José Baptista
Keyword(s):  
Green Tea ◽  
Camellia Sinensis ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Yearly Variation ◽  
Caffeine Content ◽  
Phenolic Profiles ◽  
The Impact

This study compares the antioxidant properties (RSADPPH–DPPH radical scavenging activity, FRAP–ferric reducing activity power, and FIC–ferrous ion-chelating activity), the total phenolics (TP), total flavonoids (TF), and catechin profiles, as well as the caffeine content of Azorean Camellia sinensis green tea collected in seasons of two different years. The RSADPPH showed some variation between 2019 and 2020, and presented, in general, better results in 2020 as well as during the summer seasons. The FRAP was also noted to be at its highest in July and August of the two investigated years (6.64 and 6.40 µg/mL in 2019 and 5.85 and 5.46 µg/mL in 2020). According to FIC activity, the August 2019 sample exhibited the highest value (76.18%). The TP varied between 291.14 and 326.93 mg gallic acid equivalents (GAE)/g of dried extract (DE) in 2019 and between 300.25 and 320.58 mg GAE/g DE in 2020. Concerning the TF, the values varied between 51.85 and 67.93 mg rutin equivalents (RE)/g DE in 2019 and between 50.27 and 69.57 mg RE/g DE in 2020. Epicatechins derivatives, determined by HPLC, presented higher values in all samples from 2020 compared to 2019, and the same was observed for esterified catechins. The epigallocatechin-3-gallate content was also higher in all samples from 2020 (214.52–240.16 mg/g DE) compared to 2019 (140.91–210.83 mg/g DE). Regarding caffeine content (12.86–20.45 mg/g DE in 2019 and 13.19–29.35 mg/g DE in 2020), the samples from April and June exhibited similar values in both years. In general, green tea samples exhibited better results in 2020 than in 2019, with the exception of FIC activity, while the varied TP and TF contents in certain months reflect the impact of climatic variation on tea quality.

scholarly journals FORMULATION OF A CREAM CONTAINING ETHOSOMAL GREEN TEA (CAMELLIA SINENSIS L. KUNTZE) LEAF EXTRACTS FOR IMPROVED DERMAL PENETRATION

2018 ◽  
Vol 10 (1) ◽  
pp. 221
Author(s):  
Effionora Anwar ◽  
Jeanetha Inees ◽  
Delly Ramadon
Keyword(s):  
Green Tea ◽  
Camellia Sinensis ◽  
Epigallocatechin Gallate ◽  
The Other ◽  
Polydispersity Index ◽  
Leaf Extracts ◽  
Spherical Morphology ◽  
Average Value ◽  
Dermal Penetration

Objective: This study aimed to formulate the epigallocatechin gallate (EGCG) from green tea into ethosomes and measure the resulting increases inskin penetration using a rat model.Methods: Ethosomes were formulated using ethanol concentrations of 25% (F1), 30% (F2), and 35% (F3), and those with favorable characteristicswere then incorporated into a cream for the determination of penetration into Franz diffusion cells.Results: We showed that the formulation F3 had the best spherical morphology, a Z-average value of 73.01 nm, a polydispersity index of 0.26, azeta potential of −47.77±3.93 mV, and the highest percentage of drug entrapment (49.46%±0.62%) compared with the other formulas. The totalcumulative EGCG penetration from the resulting ethosomal cream was 905.75±49.47 μg/cm2, whereas that from the cream containing green tea leafextract was only 413.92±52.83 μg/cm2.Conclusion: These data indicate a higher penetration of EGCG from ethosomal green tea cream than from cream containing non-ethosomal green teaextract.

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