scholarly journals The Influence of Water Composition on Flavor and Nutrient Extraction in Green and Black Tea

Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 80 ◽  
Author(s):  
Melanie Franks ◽  
Peter Lawrence ◽  
Alireza Abbaspourrad ◽  
Robin Dando
Keyword(s):  
Green Tea ◽  
Tap Water ◽  
Epigallocatechin Gallate ◽  
Black Tea ◽  
Deionized Water ◽  
Water Composition ◽  
The Everyday ◽  
Influence Of Water ◽  
Green And Black Tea ◽  
Degree Of Extraction

Tea is made from the processed leaves of the Camellia sinensis plant, which is a tropical and subtropical evergreen plant native to Asia. Behind water, tea is the most consumed beverage in the world. Factors that affect tea brewing include brewing temperature, vessel, and time, water-to-leaf ratio, and, in some reports, the composition of the water used. In this project, we tested if the water used to brew tea was sufficient to influence perceived flavor to the everyday tea drinker. Black and green tea were brewed with bottled, tap, and deionized water, with brewing temperature, vessel, time, and the water-to-leaf ratio matched. The samples were analyzed with a human consumer sensory panel, as well as instrumentally for color, turbidity, and Epigallocatechin Gallate (EGCG) content. Results showed that the type of water used to brew tea drastically affected sensory properties of green tea (and mildly also for black tea), which was likely driven by a much greater degree of extraction of bitter catechins in teas brewed with more purified bottled or deionized water. For the everyday tea drinker who drinks green tea for health, the capability to double the EGCG content in tea by simply brewing with bottled or deionized water represents a clear advantage. Conversely, those drinking tea for flavor may benefit from instead brewing tea with tap water.

scholarly journals The Association between Green and Black Tea Consumption on Successful Aging: A Combined Analysis of the ATTICA and MEDiterranean ISlands (MEDIS) Epidemiological Studies

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1862 ◽  
Author(s):  
Nenad Naumovski ◽  
Alexandra Foscolou ◽  
Nathan M. D’Cunha ◽  
Stefanos Tyrovolas ◽  
Christina Chrysohoou ◽  
...  
Keyword(s):  
Green Tea ◽  
Successful Aging ◽  
Coffee Consumption ◽  
Black Tea ◽  
Epidemiological Studies ◽  
Tea Consumption ◽  
Successful Ageing ◽  
Mediterranean Islands ◽  
Combined Analysis ◽  
Green And Black Tea

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.

Effect of different doses of un-fractionated green and black tea extracts on thyroid physiology

2010 ◽  
Vol 30 (8) ◽  
pp. 884-896 ◽  
Author(s):  
Amar K Chandra ◽  
Neela De ◽  
Shyamosree Roy Choudhury
Keyword(s):  
Thyroid Gland ◽  
Green Tea ◽  
Harmful Effect ◽  
Black Tea ◽  
Green Tea Extract ◽  
Male Rats ◽  
Thyroid Peroxidase ◽  
Black Tea Extract ◽  
Green And Black Tea ◽  
Tea Extract

Tea is a rich source of polyphenolic flavonoids including catechins, which are thought to contribute to the health benefits of it. Flavonoids have been reported to have antithyroid and goitrogenic effect. The purpose of this study was to evaluate whether high doses of green and black tea have a harmful effect on thyroid physiology. Un-fractionated green and black tea extracts were administered orally to male rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%. The results showed that green tea extract at 2.5 g% and 5.0 g% doses and black tea extract only at 5.0 g% dose have the potential to alter the thyroid gland physiology and architecture, that is, enlargement of thyroid gland as well as hypertrophy and/or hyperplasia of the thyroid follicles and inhibition of the activity of thyroid peroxidase and 5′-deiodinase I with elevated thyroidal Na+, K+-ATPase activity along with significant decrease in serum T3 and T4, and a parallel increase in serum thyroid stimulating hormone (TSH). This study concludes that goitrogenic/antithyroidal potential of un-fractionated green tea extract is much more than black tea extract because of the differences in catechin contents in the tea extracts.

scholarly journals Effect of Gelatin-Based Edible Coatings Incorporated with Aloe vera and Black and Green Tea Extracts on the Shelf Life of Fresh-Cut Oranges

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Mohsen Radi ◽  
Elham Firouzi ◽  
Hamidreza Akhavan ◽  
Sedigheh Amiri
Keyword(s):  
Weight Loss ◽  
Shelf Life ◽  
Green Tea ◽  
Microbial Growth ◽  
Aloe Vera ◽  
Black Tea ◽  
Quality Parameters ◽  
Fresh Cut ◽  
Green And Black Tea ◽  
Tea Extract

The aim of this study was to evaluate the effect of gelatin coating incorporated with Aloe vera gel (50,100%) and green and black tea extracts (5,10%) on physicochemical, microbial, and sensorial properties of fresh-cut oranges at 4°C for 17 days. Significant differences in terms of quality parameters were observed between the control and coated fresh-cut oranges. The highest variation of quality parameters was observed in control, while the least variations were observed in coated slices with 100% Aloe vera and 10% green tea extract. The weight loss was increased with time, but the coating treatment especially with 100% Aloe vera had significant effect on the prevention of weight loss. Also, Aloe vera coated samples obtained the highest score in sensory evaluation. Coating with gelatin incorporated with Aloe vera and green tea extracts successfully retarded the microbial growth and therefore extended the shelf life of fresh-cut oranges during cold storage.

scholarly journals Effect of Water Hardness on Catechin and Caffeine Content in Green Tea Infusions

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3485
Author(s):  
Mica Cabrera ◽  
Faizah Taher ◽  
Alendre Llantada ◽  
Quyen Do ◽  
Tyeshia Sapp ◽  
...  
Keyword(s):  
Sodium Bicarbonate ◽  
Green Tea ◽  
Tap Water ◽  
Sodium Bicarbonate Solution ◽  
Water Hardness ◽  
Deionized Water ◽  
Epicatechin Gallate ◽  
Caffeine Content ◽  
Effect Of Water ◽  
Tea Infusions

The health benefits of green tea are associated with its high catechin content. In scientific studies, green tea is often prepared with deionized water. However, casual consumers will simply use their local tap water, which differs in alkalinity and mineral content depending on the region. To assess the effect of water hardness on catechin and caffeine content, green tea infusions were prepared with synthetic freshwater in five different hardness levels, a sodium bicarbonate solution, a mineral salt solution, and deionized water. HPLC analysis was performed with a superficially porous pentafluorophenyl column. As water hardness increased, total catechin yield decreased. This was mostly due to the autoxidation of epigallocatechin (EGC) and epigallocatechin gallate (EGCG). Epicatechin (EC), epicatechin gallate (ECG), and caffeine showed greater chemical stability. Autoxidation was promoted by alkaline conditions and resulted in the browning of the green tea infusions. High levels of alkaline sodium bicarbonate found in hard water can render some tap waters unsuitable for green tea preparation.

scholarly journals Review: Telaah Kandungan Senyawa Katekin dan Epigalokatekin Galat (EGCG) sebagai Antioksidan pada Berbagai Jenis Teh

2021 ◽  
Vol 8 (1) ◽  
pp. 31
Author(s):  
Zahra Hasna Fadhilah ◽  
Farid Perdana ◽  
Raden Aldizal Mahendra Rizkio Syamsudin
Keyword(s):  
Antioxidant Activity ◽  
Green Tea ◽  
Bioactive Compounds ◽  
Bitter Taste ◽  
Epigallocatechin Gallate ◽  
Black Tea ◽  
Major Determinant ◽  
Oolong Tea ◽  
Ic50 Value ◽  
High Antioxidant Activity

Katekin merupakan senyawa bioaktif dengan kerangka flavan-3-ol dan menjadi senyawa utama penentu mutu serta dapat memberikan rasa pahit yang khas pada teh. Senyawa turunan katekin yang memiliki aktivitas sebagai antioksidan paling kuat dan melimpah yaitu epigalokatekin galat. Tujuan dari review artikel ini yaitu untuk mengetahui kandungan senyawa katekin dan epigalokatekin galat sebagai antioksidan pada berbagai jenis teh berdasarkan nilai IC50.Metode penulisan review artikel ini dilakukan dengan mencari serta menganalisis studi pustaka dari beberapa jurnal yang berkaitan dengan aktivitas antioksidan pada berbagai jenis teh dengan penelusuran terhadap senyawa katekin, khususnya epigalokatekin galat. Hasil review menunjukkan bahwa aktivitas antioksidan pada pengolahan jenis teh seperti teh hijau, teh oolong, dan teh hitam memiliki perbedaan yang cukup signifikan yang dapat dilihat dari kandungan senyawa katekin dan EGCG dimana semakin besar kandungan senyawa tersebut, maka aktivitas antioksidannya semakin tinggi. Selain itu, tingginya aktivitas antioksidan dapat dilihat dari nilai IC50. Semakin rendah nilai IC50, maka aktifitas antioksidan akan semakin tinggi. Teh hijau terbukti memiliki aktivitas antioksidan yang paling tinggi diantara teh lainnya dengan kandungan katekin sebesar 10,04% dan epigalokatekin galat sebesar 3,28% serta nilai IC50 yang paling rendah yaitu 58,61 µg/mL. Kata Kunci: Katekin, Teh Hijau, Teh Oolong, Teh Hitam, Antioksidan Catechins are bioactive compounds with a flavan-3-ol structure and become a major determinant of quality compounds and can give a distinctive bitter taste of tea. Catechin derivative compounds that have the antioxidant activity as the strongest and abundant are epigallocatechin gallate. The purpose of this article review was to determine the content of catechins and epigallocatechin gallate compounds as an antioxidant in various types of tea based on the IC50 value. The method of writing of this article review was carried out by searching and analyzing literature studies from several journals related to antioxidant activity in various types of tea by tracing catechin compounds, especially the epigallocatechin gallate. The results of the review showed that the antioxidant activity in the processing of types of tea such as green tea, oolong tea, and black tea has significant differences which could be seen from the content of catechins and EGCG compounds where the greater the content of the compounds, the higher the antioxidant activity. Also, the high antioxidant activity can be seen from the IC50 value. The lower the IC50 value, the higher the antioxidant activity. Green tea shows to have the highest antioxidant activity among other teas with a catechin content of 10.04% and an epigallocatechin gallate of 3.28% and the lowest IC50 value of 58.61 µg/mL.

scholarly journals Acute cognitive, mood and cardiovascular effects of green and black tea

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Andrew Scholey ◽  
Alicia Burns ◽  
Matt Pase ◽  
Andrew Pipingas
Keyword(s):  
Green Tea ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Cardiovascular Function ◽  
Cardiovascular Effects ◽  
Black Tea ◽  
Assessment System ◽  
Taste Masking ◽  
Double Blind ◽  
Green And Black Tea

AbstractTea is often described as having “refreshing” properties. Indeed, components of both green and black tea have been shown to acutely improve aspects of cognition and mood and to affect cardiovascular function. There is, however, surprising little research directly comparing these effects between different types of tea. This study therefore examined acute cognitive, mood, and cardiovascular effects of green tea and black tea.A double blind, randomised, placebo-controlled,balanced, three-way cross-over study was conducted. Fourteen healthy young adults (M = 23.8, SD = 3 years) consumed placebo (water), green tea and black tea in balanced order at least 24 h apart.The drinks were prepared according to standardised procedures and consumed under double-blind conditions (in opaque containers with lemon cordial added for taste-masking). Mood and cognition were measured at baseline then 90 min post-treatment, cardiovascular function was assessed post-dose only. Mood was evaluated using a series of visual analogue scales, cognitive performance was assessed using a suite of standardised tests from the Computerised Mental Performance Assessment System (COMPASS), gauging performance on aspects of attention, memory and executive function.Peripheral and central systolic and diastolic pressure,augmentation pressure, augmentation index,and blood flow velocity were measured via Sphygmocor pulse wave analysis and Doppler ultrasound, respectively. There were a number of significant effects associated with the active treatments. Compared with placebo, black tea and green tea was associated with significantly improved digit vigilance accuracy (p < .01), while green tea was associated with higher alertness (p < .05).Regarding cardiovascular outcomes, black tea and green tea significantly increased central diastolic pressure, and peripheral diastolic pressure in comparison to placebo (P < .01). Black tea also significantly increased central systolic pressure compared to green tea and placebo (p < .05). Analysis of treatment guessing suggested that the masking procedure was highly effective. In conclusion, the present study shows that green tea improves alertness. Since black tea contains higher levels of caffeine, this effect is likely underpinned by non-caffeine mechanisms or caffeine/non-caffeine compound interactions.Improved vigilance is consistent with caffeine effects which may be modulated by cardiovascular effects. Interestingly the cardiovascular effects are opposite to those reported for chronic tea interventions. These results suggest that acute cognitive and cardiovascular components of tea merit further investigation both in the presence and absence of caffeine.

scholarly journals Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 721
Author(s):  
Eriko Ohgitani ◽  
Masaharu Shin-Ya ◽  
Masaki Ichitani ◽  
Makoto Kobayashi ◽  
Takanobu Takihara ◽  
...  
Keyword(s):  
Virus Infection ◽  
Green Tea ◽  
Virus Titer ◽  
Epigallocatechin Gallate ◽  
Black Tea ◽  
Human Saliva ◽  
Detectable Level ◽  
Healthy Human ◽  
Rapid Inactivation

Saliva plays major roles in the human-to-human transmission of SARS-CoV-2. If the virus in saliva in SARS-CoV-2-infected individuals can be rapidly and efficiently inactivated by a beverage, the ingestion of the beverage may attenuate the spread of virus infection within a population. Recently, we reported that SARS-CoV-2 was significantly inactivated by treatment with black tea, green tea, roasted green tea and oolong tea, as well as their constituents, (-) epigallocatechin gallate (EGCG), theasinensin A (TSA), and galloylated theaflavins. However, it remains unclear to what extent tea inactivates the virus present in saliva, because saliva contains various proteins, nitrogenous products, electrolytes, and so on, which could influence the antivirus effect of tea. Here, we assessed whether tea inactivated the SARS-CoV-2 which was added in human saliva. A virus was added in healthy human saliva in vitro, and after treatment with black tea or green tea, the infectivity of the virus was evaluated by TCID50 assays. The virus titer fell below the detectable level or less than 1/100 after treatment with black tea or green tea for 10 s. The black tea-treated virus less remarkably replicated in cells compared with the untreated virus. These findings suggest the possibility that the ingestion of tea may inactivate SARS-CoV-2 in saliva in infected individuals, although clinical studies are required to determine the intensity and duration of the anti-viral effect of tea in saliva in humans.

scholarly journals Uji Pendahuluan Anti-biofilm Esktrak Teh Hijau dan Teh Hitam Pada Streptococcus mutans melalui Metode Microtiter Plate

2018 ◽  
Vol 4 (1) ◽  
pp. 44-49
Author(s):  
Andi Arjuna ◽  
Winda Setya Pratama ◽  
Sartini Sartini ◽  
Mufidah Mufidah
Keyword(s):  
Streptococcus Mutans ◽  
Green Tea ◽  
Black Tea ◽  
Microtiter Plate ◽  
Green Tea Extract ◽  
Biofilm Growth ◽  
Microtiter Plate Assay ◽  
Black Tea Extract ◽  
Green And Black Tea ◽  
Tea Extract

Tea (Camellia sinensis L.) has an activity as an antibacterial, widely studied to plankton cells, without further researching into biofilm cell. Therefore, this research had been conducted to initially evaluate the activity of green- and black-tea extracts in inhibiting Streptococcus mutans biofilm. Green and black tea leaves were extracted using 70% methanol. Determination of MIC was subsequently performed by microdilution method. Next, the biofilm formation and inhibition were run through microtiter plate method using flexible U-bottom PVC 96 wells, which then observed using microplate reader on λ = 515 nm. As The results, MIC for green and black tea extract stood at 4 mg/mL, 6 mg/mL respectively. The biofilm inhibitory activity of black tea extract was at 8 and 10 mg/mL inhibiting 6 % and 12.5 % S. mutans. Green tea extract showed that concentration of 4 to 10 mg/mL was able to inhibit biofilm growth by 24%; 45%; 48% and 53%. Thus, through microtiter plate assay, it could be concluded that tea extract has potent antibiofilm to S. mutans, where green tea extract has better activity than black tea extract.

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