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Black tea is a healthy and popular tea beverage. However, its main bioactive compounds (theaflavins and thearubigins) are not easily absorbed. The aim of this study was to investigate the modulation of intestinal microbiota by the nonabsorptive components of Keemun black tea (KBT) and Dianhong black tea (DBT), and fructooligosaccharide (FOS) was selected for use in the control group. KBT, DBT, and FOS significantly increased total short-chain acid production. Specifically, FOS treatment predominantly increased the production of acetic acids and black tea treatments increased the production of acetic, propionic, and butyric acids at similar rates. Moreover, FOS exerted a strong bifidogenic effect after 24 h of fermentation; KBT and DBT increased the abundance of the beneficial genus Bacteroides and Roseburia. In summary, the nonabsorptive components of KBT and DBT could serve as novel prebiotics, the underlying mechanisms of which are quite different from those of FOS.

Dark tea (containing Eurotium cristatum) and black tea have hypoglycemic effects. The black brick tea with fungal growth is obtained from black tea by adding E. cristatum, followed by steaming, pressing, fungal growth, and drying. However, the hypoglycemic effects of black brick tea are still unexplored. Here, we used black brick tea with fungal growth and black tea as raw materials to study their hypoglycemic effects in a hyperglycemic mice model. Both these types of black tea could lower the content of blood glucose and increase the content of hepatic glycogen by upregulating the proteins and mRNA expression of phosphatidylinositol-4,5-bisphosphate3-kinase, glycogen synthase, protein kinase B and phosphoinositide-dependent protein kinase-1 and downregulating the protein and mRNA expression of glycogen synthase kinase 3β. These regulatory steps were followed by high activities of glutathione peroxidase and superoxide dismutase and low content of malondialdehyde. These teas can promote blood glucose transport and absorption by upregulating the protein and mRNA expression of insulin receptor substrate-1 and glucose transporter-2 and stimulate glycolysis by upregulating the protein and mRNA expression of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2. Our study suggests that the black brick tea was more effective than the black tea in terms of hypoglycemic.

It is well known that black and green tea extracts, particularly polyphenols, have antimicrobial activity against various pathogenic microbes including viruses. However, there is limited data on the antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), which emerged rapidly in China in late 2019 and which has been responsible for coronavirus disease 2019 (COVID‐19) pandemic globally. In this study, 20 compounds and three extracts were obtained from black and green tea and found that three tea extracts showed significant antiviral activity against SARS‐CoV‐2, whereby the viral titre decreased about 5 logs TCID50 per ml by 1·375 mg ml−1 black tea extract and two‐fold diluted tea bag infusion obtained from black tea when incubated at 25°C for 10 s. However, when concentrations of black and green tea extracts were equally adjusted to 344 µg ml−1, green tea extracts showed more antiviral activity against SARS‐CoV‐2. This simple and highly respected beverage may be a cheap and widely acceptable means to reduce SARS‐CoV‐2 viral burden in the mouth and upper gastrointestinal and respiratory tracts in developed as well as developing countries., Significance and Impact of the Study: Here, we show that black tea extract and tea bag infusion could reduce the viral titre of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in vitro by 5 logs TCID50 per ml within 10 s. Black and green teas are widely available and are relatively cheap to purchase in both developed and developing countries. In translational terms, drinking tea might contribute to the in vivo reduction in numbers of SARS‐CoV‐2 virus in saliva of infected persons, as well as lowering the viral burden in the mouth and upper gastrointestinal and respiratory tracts. A clinical trial is urgently needed to establish if drinking tea results in the prevention of transmission of SARS‐CoV‐2 virus between infected and non‐infected persons.

Free radicals are one of the triggering factors for degenerative diseases. Free radical activity can be minimized or prevented in the presence of antioxidant compounds. The butterfly pea flower (Clitoria ternatea L.) has long been used as a traditional medicine to cure various diseases. Previous research has shown that the Butterfly pea flower has bioactive compounds, one of which is flavonoids, which act as antioxidants. Butterfly pea flower can be used as another substitute in making black tea-based kombucha drinks. Kombucha fermentation can increase the benefits of Butterfly pea flower with the presence of organic acids, minerals, and vitamins produced during the fermentation process. This study aims to determine the effect of fermentation time on chemical characteristics including pH, reducing sugar content, and antioxidant activity. Based on analysis of variance ANOVA showed that the length of time fermentation had a very significant effect (P>0.01) on pH, reducing sugar content and antioxidant activity of black tea and Butterfly pea flower kombucha. The longer the fermentation time, the lower the pH and sugar content in the medium. Optimum antioxidant activity occurred on the 8th day of fermentation in the variation of treatment P3 (3:3) which was 89.74%. These results indicate that black tea kombucha and Butterfly pea flower are categorized as having high antioxidant activity at the interval of 68.45% to 89.74%.

Black tea contains flavonoid and its derivate which is a mechanism of actions to stimulate and increase cell proliferation of hair dermal papilla cell to suppress the production of tumor necrosis factor alpha (TNF alpha) that trigger baldness. This study aimed to determine the stable hair tonic formula and to investigate the effectiveness of black tea extract hair tonic in rabbits (oryctolagus cuniculus) as animal testing. There were 3 different concentrations used in this study namely formula 1 (1.25 % of black tea extract), formula 2 (2.5 % of black tea extract) and formula 3 (5 % of black tea extract). The physical stability evaluation was conducted using some tests such as organoleptic, pH, density determination and viscosity test. The result of this evaluation showed that all the three formulas were stable, its effectiveness as hair restorer then was tested and the result of this test indicated that black tea extract has activity as a hair fertilizer and the optimum extract was shown by the formula 3 with black tea extract concentration of 5% with the hair growth in the 18th day i.e., 9.62 ± 0.365 mm.

Camellia sinensis (L.) O. Kuntze (tea) is one of the most widely consumed beverages across the world, serving as an essential commodity crop for several developing countries. A bulk of tea’s health-promoting properties are attributed to the antioxidant properties of EGCg, its predominant polyphenol. As a result of these health benefits, tea production and consumption has expanded and promoted the development of tea industries globally. Tea cultivation is dependent on a good distribution of rainfall, and the current changes in climate pose a significant threat to its global supply chains. Through the efforts of the International Centre for Tropical Agriculture (CIAT), predictions of future climate changes in the tea growing regions of Kenya between now and 2050 have been generated. A study was conducted to develop models to identify key tea growing regions that will remain ideal for tea farming and also investigate the metabolomic differences between 243 drought susceptible NonCommercial (NComm) and 60 Commercial (Comm) cultivars. Non-targeted, high-resolution UPLC-MS was used to attain a new profound understanding of the metabolomic multiplicity between the Comm and NComm groups and to elucidate their association with tea liquor quality and drought tolerance. Several metabolites, namely argininosuccinate, caffeic acid, caffeine, catechin, citric acid, epicatechin, epigallocatechin gallate, gallic acid, gluconic acid, glucose, maltose, quercetin and theanine were found to clearly differentiate between the Comm and NComm cultivars. These detected metabolites were linked to improved tea quality and drought tolerance in the Comm cultivars.

Introduction: Tea is a popular beverage that comes from Camellia sinensis. Tea is generally categorised into four types: black tea, oolong tea, green tea, and white tea. These four types are distinguished based on the presence or absence of a fermentation process during their processing. One of the compounds that play a role in providing freshness to tea is caffeine. Aims: The purpose of this study was to determine the caffeine content in the tea samples that are on the market. Methods: This was done using the near-infrared (NIR)-chemometric method and using the TLC-Densitometry method as a comparison. Infrared (IR) spectroscopy combined with chemometrics has been developed as a simple method to analyse the caffeine content in a tea sample. IR spectra of tea samples were correlated with caffeine content using chemometrics. Results: In this study, the partial least squares (PLS) model of the NIR model that showed the best calibration with r-square was 0.958, and the root mean squared error of calibration (RMSEC) value was 0.070. The PLS calibration model of the NIR models was further used to predict the unknown caffeine content in commercial samples. The significance of the caffeine content that had been measured with NIR and TLC-Densitometry was evaluated using a two paired sample t-test. Conclusion: The caffeine content measured with both methods gave no significant difference.

Tea is a rich source of functional components called polyphenols which impart it antioxidant properties. Tea is categorized as green or black tea according to the processing method used. Tea is widely consumed beverage, and it is often prepared with the addition of milk and sugar in many parts of the world including India. The present study was conducted to compare the effect of addition of milk and/or sugar, in both black and green teas of two brands (1 and 2), on the antioxidant properties of teas. The total polyphenol, flavonoid and catechin contents along with antioxidant activity were significantly (p

In this research, kombucha tea was prepared using 5 different tea extracts and physicochemical and sensory analyses were made. The tea extracts used are black tea, green tea, sage, linden and mint, respectively. The prepared tea samples were subjected to fermentation for 14 days. In tea samples, pH, electrical conductivity, water-soluble solid and phenolic components were analyzed before and after fermentation. pH values decreased by an average of 63% in all tea samples after fermentation. The electrical conductivity increased in black tea, green tea and mint tea, while sage and linden decreased. Brix values decreased in all tea samples, the most decrease was in black tea. Total amount of phenolic contents of kombucha tea samples decreased excluding mint tea sample. As a result of sensory analysis of tea samples, mint tea got the highest score. As a result of the research, it has been determined that the kombucha tea, which is usually made with black and green tea, can be prepared with teas of different flavors and its consumption can be increased. © 2021, Sociedade Brasileira de Ciencia e Tecnologia de Alimentos, SBCTA. All rights reserved.

Aquilaria is one of the plant genus-producing agarwood. Aquilaria leaves have pharmacological effects which the potential to be processed into black tea. The aim of this study is to determine the effect of fermentation duration on physicochemical and organoleptic characteristics of Aquilaria leaves tea. This study employed a Completely Randomized Design with two factors; the plant species (A. crassna, A. malaccensis, and A. subintegra) and fermentation duration (0 minutes, 70 minutes, and 90 minutes). Parameters analyzed including water content, total phenol, and antioxidant activity. Organoleptic tests were performed on the color, taste, and aroma of the brewed tea. The results summarized that A. subintegra had the highest total phenol and antioxidant activity, but the taste of the tea was not favored. A. crassna fermented 70 minutes and A. malaccensis fermented 0 minutes were the most preferred, but both have lower total phenol and antioxidant activity than A. subintegra. Keywords: Aquilaria , Antioxidant activity, Organoleptic test, Tea, Total phenol

Although black tea and dark tea are both fermented teas, their fermentation processes are varied a lot and strongly affect their chemical components. The flavonoids which are the major active compounds in teas play an important role in their refreshing effect and health benefit. The differential flavonoid glycosides in these two fermented teas were investigated using nontargeted modification-specific metabolomics UHPLC–MS method. Principal component analysis (PCA) and orthogonal projection on latent structure-discriminant analysis (OPLS–DA) showed that these two types of fermented teas could be clearly distinguished according to their characteristic secondary metabolites. 218 glycosylated records were found out through six specific glycosylated neutral loss calculations. After intersection calculations between glycosylated metabolites and differential secondary metabolites, seven flavonoid glycosides markers were identified which contribute to the classification of two kinds of fermented teas. According to the experimental results, the contents of flavonoid glycosides may strongly relate to the fermented processing technology and microbial fermentation of dark tea would decrease the contents of flavonoid glycosides. The proposed strategy could provide a feasible and reliable technique to understand the glycosylation level under different treatments.

Flavonoid compound is an important compound of tea products. However, the flavonoid level content in black tea is lowest than other teas. This is due to the processing of black tea which has an enzymatic oxidation stage and the tea age leaves when picking. Young tea leaves contain higher total flavonoids than old tea leaves. With an average level of total flavonoids, the young tea leaves is 27.76% qe w / w, while for the old tea leaves 18.61% qe w / w. However, the enzymatic oxidation time treatment did not affect the total flavonoids because the process only affected the quality of black tea steeping, on it ’s colour, aroma, and taste. Keywords: age of tea leaves, black tea, enzymatic oxidation, total flavonoids

Inflammatory bowel disease (IBD) is a chronic gastro-intestinal disorders of unknown etiology. There are several drugs approved for treating IBD patients with active disease, including first-line use of aminosalicylates, and secondary choices of immunomodulators and other therapies. These medications might manage disease symptoms, but have also shown significant side-effects in IBD patients. Tea is the second largest beverage in the world and its main active ingredients including tea polyphenols, polysaccharides and tea pigments have been shown promising anti-inflammatory and antioxidant properties. In this review, we summarize the influence of different tea varieties including green tea, black tea and dark tea as potential nutritional therapy for preventing and treating IBD, and discuss the mechanisms of tea ingredients involved in the regulation of oxidative stress, inflammation, signaling pathways, and gut microbiota that could benefit for IBD disease management. Our observation directs further basic and clinical investigations on tea polyphenols and their derivatives as novel IBD therapeutic agents.

The purpose of this study was to determine the antioxidant activity of fermented tea (black tea) with Ketapang leaves (Terminalia catappa) using two variations of leaf age, namely leaflets 1-3 and 4-5. The parameters observed were water content, pH, antioxidant activity (IC 50 ) and total phenol content of tea. R esults showed that the antioxidant activity of young leaves (shoots 1-3) significantly higher than old leaves (shoots 4-5) but had lower total phenol and pH. In general, the character of Ketapang leaf tea products at shoots 1-5 has water content ranging from 5.55-5.58%, total phenol content of 22.63-28.97 mg / g EAG, and antioxidant activity (IC 50 ) of 6.27-6 . 71 µg/ml and the pH of steeping water from 5.9 to 6.1.

Combined withering and shaking processes are key steps in the formation of characteristic floral and fruity aromas in black teas. However, the effect of the sequencing of withering and shaking on volatile compounds and aroma formation in black tea has not been evaluated to date. This study used headspace solid-phase microextraction and gas chromatography-tandem mass spectrometry to detect volatile compounds in black teas after withering-shaking and shaking-withering processing. Five main differentially volatile components were screened out by partial least squares discriminant analysis and odor activity value analysis, which were 3-carene, geraniol, β-myrcene, τ-cadinol, and β-ionone. Additionally, sensory evaluation showed black tea produced by withering-shaking was fruitier, while shaking-withering produced a more floral tea. This study provides a theoretical basis for the discrimination of aroma characteristics of black tea processed by shaking, as well as a technical guide for the precise production of black teas with different floral-fruity aroma biases.

The aim of the study was to determine the type of solvent that allows the most complete extraction of antioxidant substances from white, black and green tea (Camellia sinensis). The objects of the study were extracts of three types of tea obtained using various solvents: water, a mixture of water-ethanol (75% vol./25% vol.), A mixture of water-ethanol (50% vol./50% vol.), A mixture of water -ethanol (25% vol./75% vol.) and ethanol (96%). In extracts of white, black and green tea, the total content of phenolic substances, flavonoids, antiradical activity by the DPPH method, and the restoring force by the FRAP method were determined. The maximum values of the total content of phenolic substances were found in the extract of white tea based on ethanol and a water-ethanol solvent system (50/50), black tea when extracted with water, green tea with a water-ethanol solvent ratio (50/50). High values of the total content of flavonoids were established for white tea extract based on a water-ethanol solvent system (50/50), black tea when extracted with water, green tea, when using ethanol as a solvent. Low antiradical activity was found in white tea extract based on a water-ethanol solvent system (50/50), in ethanol-based black tea, and green tea showed low values when extracted with water. The highest index of restorative power was found in white tea extract based on a water-ethanol solvent system (25/75), in black and green tea when extracted with water. Thus, as a result of the study of extracts of white, black and green tea, it was found that when the white tea is extracted with a water-ethanol (50/50) solvent system, the largest amount of antioxidant substances is extracted. The maximum amount of antioxidants from black and green tea is extracted using water as a solvent.

Tea is a widely renowned functional beverage originating from processed tender leaves of the Camellia sinensis plant after brewing with hot water. This refreshing and revitalizing beverage has been recognized as an essential commodity since ancient times. Tea constituents have many health benefits and hence find usage in functional foods, beverages, and nutraceuticals. Nonetheless, the clinical usage of tea constituents is limited by the high molecular weight, poor stability, and low bioavailability of some active components. We review how fresh tea leaves are processed into different forms of tea such as green, oolong, white, and black teas. The major tea constituents, e.g., catechins, caffeine, and theanine, exhibit numerous health properties such as antioxidant, anti-inflammatory, anticancer, antidiabetic, cardioprotective, and antimicrobial. We discuss methods to enhance the efficacy and applicability of active tea constituents, such as micro- and nanoencapsulation techniques.

In recent years, the green process method is attaining mild impact ailments and are nontoxic antecedents and are emphasized in the advancement of nanotechnology. This process subsists environmental sustainability. This study intended for eco-friendly synthesis of iron nanoparticles by using green tea and black tea leaves extract. Polyphenols are the components present in the plants used for the synthesis of metal nanoparticles and are replaced by chemical components. This component is nonlethal and biodegradable. Plants evoke more reliable nanoparticles related to other norms. Green synthesis methods do not require high temperature and energy. The characterization of the Fe- Nanoparticles function is done by using SEM and XRD techniques.

The aim of current research was to determine the effect of different extraction techniques on the antioxidant capacity of green tea, black tea and ginger polyphenols. Initially, the raw materials were subjected to compositional analysis. Afterward, the bioactive moieties from all the samples were extracted through ultrasound and conventional solvent extraction method using different solvents (i.e. ethanol, methanol and water). Furthermore, the functional ingredients, namely, catechins and theaflavins were isolated by solvent partition method from green and black tea, respectively. In addition, the extracts and isolates were analyzed for their total phenolic and antioxidant profile using various spectrophotometric assays. For the quantification of theaflavins and catechins, a reverse phase HPLC system was used. Results showed that ultrasound (P > .005) proved more effectual for the extraction and isolation of polyphenols (757.33 mg/100 g GAE) from the tested materials among the other extraction techniques (741.66 mg/100 g GAE). Likewise, green tea showed better performance than the rest and in solvents ethanol performed better as compared to their counter parts. Similarly, the isolates showed higher antioxidant potential as compared to their extracts and order of effectiveness was catechins > theaflavins > Ginger freeze dried extract (GFDE).

The aim of this study was to determine the levels of myricetin, quercetin, and kaempferol in green and black Kenyan types in relation to geographic location of production. Tea samples were extracted before chromatographic separations with a Shimadzu 20A HPLC coupled with PDA. Flavonol levels were quercetin > kaempferol > myricetin. Teas from east of rift, had quercetin 1.25-1.83 mg/g and 1.29-1.71 mg/g for green and black types, respectively. Kaempferol levels were between 1.28-1.72 mg/g in green and 1.36-1.76 mg/g in black tea. Myricetin ranged at 0.40-0.79 mg/g green and 0.12-0.38 mg/g black tea types. Total flavonols in green tea were highest at 4.28 mg/g while black tea was 3.83 mg/g. These trends agree well with those observed in teas west of the rift. For tea types, myricetin and kaempferol showed a significant difference (P ≤ 0.05) between green and black teas. Total flavonols showed no significant difference. Kenyan teas are a potential dietary source of flavonols myricetin, quercetin, and kaempferol as evidenced by the significant quantities recorded in this study.

Black tea accounts for 70-80% of world tea production, and the polyphenols therein are produced by enzymatic oxidation of four tea catechins during tea fermentation. However, only limited groups of dimeric oxidation products, such as theaflavins, theasinensins, and theacitrins, have been isolated from black tea and chemically characterized. This is largely because of the complexity and heterogeneity of the oxidation products. To determine structures and production mechanisms of uncharacterized black tea polyphenols,in vitro model fermentation experiments using pure catechins and polyphenol oxidase have been applied, and basic oxidation mechanisms have been established. Contemporary methods, such as LC-MS, are also effective to identify catechin oxidation products in black tea. Despite ongoing efforts, almost 60% of the solids in black tea infusion remain uncharacterized. These compounds include the so-called thearubigins, which are a heterogeneous mixture of uncharacterized catechin oxidation products with oligomeric structures. This review summarizes the current knowledge of the production mechanisms of representative black tea polyphenols and presents recent progress in characterization of thearubigins.

Black tea accounts for 70-80% of world tea production, and the polyphenols therein are produced by enzymatic oxidation of four tea catechins during tea fermentation. However, only limited groups of dimeric oxidation products, such as theaflavins, theasinensins, and theacitrins, have been isolated from black tea and chemically characterized. This is largely because of the complexity and heterogeneity of the oxidation products. To determine structures and production mechanisms of uncharacterized black tea polyphenols,in vitro model fermentation experiments using pure catechins and polyphenol oxidase have been applied, and basic oxidation mechanisms have been established. Contemporary methods, such as LC-MS, are also effective to identify catechin oxidation products in black tea. Despite ongoing efforts, almost 60% of the solids in black tea infusion remain uncharacterized. These compounds include the so-called thearubigins, which are a heterogeneous mixture of uncharacterized catechin oxidation products with oligomeric structures. This review summarizes the current knowledge of the production mechanisms of representative black tea polyphenols and presents recent progress in characterization of thearubigins., Chemical & pharmaceutical bulletin, 68(12), pp.1131-1142; 2020

Heavy metal pollution is one of the environmental problems and one of the critical concerns of food hygiene. Consumption of tea as a pleasant drink and food habit is common among Iranians.The prese...

The article contains theoretical and practical information, including the basic requirements for black tea, methods for evaluating organoleptic indicators. Tasting remains one of the preferred methods of assessing the quality of tea. Tea tester evaluates such properties of the drink (aroma and taste shades, the presence of foreign odors and tastes) that cannot be obtained by other methods. When carried out correctly, organoleptic analysis gives no less objective results than instrumental analytical methods. To a certain extent, it is more informative, since it allows you to evaluate the product from the point of view of the consumer and his preferences.

Contemporary consumers drink significant amounts of tea because of its health–benefits mainly associated to the presence of polyphenols with high antioxidant activity. Therefore, the information how to obtain tea infusion of the highest quality, i.e. with high antioxidant capacity is needed. In this study, the various models for the prediction of total polyphenols and antioxidant activity of green and black tea infusions were developed and compared. Three mathematical equations: Spiro’s, Peleg’s and logarithmic, and two data mining techniques: multivariate adaptive regression splines (MARS) and artificial neural networks (ANNs) were used to build the predictive models. The results obtained show that Spiro’s model could be used for the prediction of green tea quality expressed as total phenolic content or the antioxidant activity (determination coefficients above 0.99), whereas Peleg’s model is more suitable for black tea quality prediction (determination coefficients above 0.99). Data mining techniques (MARS and ANNs) enable to create models fast and of simple application with very good acceptability (determination coefficients above 0.99).

Anthocyanins are important bioactive supplements that are consumed from multiple foods and beverage products. Screening tea cultivars producing a high level of anthocyanins can help to enrich the edible bioactive supplements. ‘Zijuan’ (ZJ) is a tea cultivar growing purple shoots rich in anthocyanins, but it is susceptible to freezing winter and sprouts late in spring. Hybridisation using ‘ZJ’ as the female parent and an early sprouting cultivar ‘Wuniuzao’ as the male parent was carried out, and four hybrids with purple leaves were obtained. The quality of anthocyanins, catechins, caffeine and amino acids in shoots with three leaves and a bud of the purple leaf hybrids obtained were determined based on the field investigation on sprouting time in spring, winter resistance and leaf yield. It showed that hybrid ‘B-2’ sprouted earlier in the spring, contained a higher level of anthocyanins and also showed good performance in winter resistance than its female parent ‘ZJ’. It also showed that black tea processing induced a marked decrease in foliar anthocyanins, but green tea processing had little effect on the foliar anthocyanins. Purple tea leaves should be prepared into unfermented green tea instead of fermented black tea to preserve the high level of anthocyanins in the final tea products.

The use of waste materials in concrete has been accelerated around the world recently. In this study, thermal and compressive strength properties of concrete doped with black tea waste are studied to assess the availability of using this type of waste in concrete. Black tea waste with 0.3 and 0.5 vol.-% were added to concrete mixtures. Thermal conductivity and effusivity of concrete with black tea waste were evaluated firstly, and load-bearing capacity of this biomass doped concrete were also investigated by the compressive test and Schmidt hammer test. The results showed that using black tea waste with 0.3 vol.-% slightly decreased the compressive strength of concrete whereas there was a considerable decrease in thermal conductivity. However, using black tea waste with 0.5 vol.-% causes an obvious decrease in compressive strength and a decrease in thermal conductivity of concrete which is not directly proportional with the amount of black tea. Therefore, with a small toleration of loss of compressive strength, black tea waste doped concrete can be produced with high volume fractions in order to have concrete samples with good thermal insulation for research purposes.

Tea was known as one popular and power-consuming beverage. The purpose of the current study was to determine the concentration of heavy metals in infused tea consumed in Kashan City. This cross-sec...

This study uncovered the chemical changes during kombucha's fermentation process and revealed the associated immunomodulatory activity in Salmonella typhi-infected mice. The snake fruit juice and black tea extract were processed into kombucha (a beverage known for its health benefits) by fermentation with SCOBY culture at room temperature for 14 days. Snake fruit kombucha showed high changes in fermentation parameters (total acidity, pH, and total sugar), as well as bioactive compounds and antioxidant activity. Salmonella typhi demonstrated a reduction in the population of CD8+TNFα+ and CD4+IFNγ+ of infected experimental animals. Both snake fruit kombucha and black tea kombucha have the potential to be utilized as an immunomodulator to circumvent unstable conditions of the immune system caused by Salmonella typhi. Black tea kombucha and snake fruit kombucha cancan raise the production of CD8+TNFα+ and CD4+IFNγ+ in mice infected with Salmonella typhi. In the group of normal mice, black tea and snake fruit kombucha were able to lower down the production of CD8+TNFα+, which is a potent mechanism to modulate the immune system. Further research is required to highlight the mechanism and role of black tea kombucha and snake fruit kombucha in the immune response that modulates and treats infection by Salmonella typhi.

Community associated strains of Staphylococcus aureus were isolated and treated with extracts of Catharanthus roseus and Camellia sinensis (black tea) to examine their antibacterial potential, eith...

Tea is one of the most consumed beverages in the world. Majority of people consume black tea more than green tea. Green tea is prepared from the dry leaves of Camellia sinensis bush. The extent of oxidation of the leaves determines the type of tea prepared. Green tea is made from the un-oxidised tea leaves and is a type of less processed tea. Therefore, it contains the most number of antioxidants and beneficial phenols. These polyphenols prevent the acid production of bacterial species like Streptococcus mutans and Porphyromonas gingivalis, which are solely involved in the development of dental caries and periodontal diseases. Around 30 articles from Pubmed and other Scopus indexed journals were collected and the data was extracted from them. The articles were selected based on their relevance to the topic and characteristics. The review methods, applications of green tea in various systems, applications of green tea in dentistry and their risk and side effects were discussed. The above topics were discussed accurately and the data was selected accordingly. The topic was discussed to see whether green tea can be used in dentistry.

Tea as a refreshing beverage is consumed socially and habitually. Tea contains several bioactive compounds. The present research work has been designed to work on characterization of tea and tea infusion collected from major tea growing regions of India as climate influences aroma and taste of tea. CTC-tea and Orthodox-tea (O-tea) samples were collected from different tea growing regions of India. In both the type of tea samples maximum and minimum percentage of moisture were recorded in Nilgiri and Dooars tea. Amount of Crude fibres in manufactured CTC-tea was more than O-tea. Ash content of CTC-tea and O-tea ranged between 1.308%-1.66% and 0.233-0.315% respectively. The pH of infusions was found to be acidic. Optical density of O-tea infusions was found to be less than CTC-tea infusions. Insoluble and soluble matter in tea infusions was extremely variable. Theaflavin of tea infusions prepared from CTC-tea were more than that of O-tea of the same region. Thearubigins was recorded more in all CTC-tea samples over O-tea except for the sample manufactured at Nilgiri. Caffeine content was high in CTC-tea samples of Nilgiri, Terai and Shillong whereas for Assam and Dooars it was high in O-tea. Free radical scavenging activity was more in CTC-tea than O-tea of the same region. O-tea showed better antibacterial activity than CTC-tea.

Black tea powder was used to make tea infusion using a Keuring coffee maker. Effect of tea particle size (0.30 or 0.60 mm), water volume for brewing (118, 177, or 236 ml), and the amount of tea powder (1.0, 1.5, or 2.0 g) on tea infusion quality were evaluated. The concentration of four chemical compounds (soluble sugars, total amino acids, polyphenols, and caffeine) in tea infusion was measured. In general, the concentration of the four compounds in tea infusion increased with the amount of tea powder used and decreased with increasing water volume and tea particle size. Using 2.0 g of 0.30 mm tea powder and 118 ml of water per brew, the concentration of the above four components was 412.3, 251.6, 208.9, and 205.3 μg/ml, respectively, and higher than tea infusion prepared by traditional method (312.4, 204.1, 211.6, and 175.9 μg/ml). The highest extraction efficiency (mg/cup.g) for the four chemical components per unit weight of tea powder was at using 1.0 g of 0.30 mm tea powder with 236 ml water for soluble sugars (32.3 μg/ml) and caffeine (16.3 μg/ml), at using 1.5 g tea powders for polyphenols (22.3 μg/ml) and at using 2.0 g tea powders for amino acid (13.6 μg/ml). This study suggested using a single‐serve coffee maker can be a convenient and effective way to prepare the tea infusion with high quality., Results obtained from this study demonstrated that the single‐serve coffee maker can be a convenience tea brewing method and tea infusion quality can be optimized based on consumer preference.

Anthraquinone (AQ) levels in some Indonesian dried tea leaves samples from different plantation areas and their brewed tea samples were determined by gas chromatography-tandem mass spectrometry methods. The mean lower bound, middle bound, and upper bound of AQ levels in 59 dried tea leaves samples were 82.2, 82.8, and 83.4 μg/kg, respectively, while their 95%th percentile values were identical at 190.3 μg/kg (0.1903 mg/kg). In a transfer rate study, the mean and 95%th AQ levels in 30 dried tea leaves samples with AQ level ≥ LOQ (limit of quantification) were 128.6 and 194.5 μg/kg (0.1945 mg/kg), while those of their corresponding brewed tea samples were 2.1 and 3.4 μg/kg, respectively. The mean and 95%th transfer rates of AQ into brewed tea samples were 51.99 and 88.17%. Using these data and taking into account daily tea consumption, calculated cancer potency slope factor, benchmark dose of 10% effect at lower bound 95% confidence interval of AQ, and average body weight, the risk characterization due to exposure to this compound from tea consumption was calculated and stated as incremental lifetime cancer risk (ILCR) and margin of exposure (MOE). The overall results revealed that AQ levels in dried tea leaves up to the highest level found in the samples lead to an ILCR of not more than 10-6 and an MOE of not less than 104 and hence was predicted to give sufficient consumer protection.

In this study, 170 tea samples were investigated for the occurrence of 9,10-anthraquinone (AQ), which was collected from Shandong Province of China in 2018. The contamination levels of AQ were detected by a combination of QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure with gas chromatography tandem mass spectrometry. Under the optimal conditions, the linear range for AQ was from 10 to 200 ng/mL. The recoveries ranged from 95.6% to 101%, with the coefficient of variation less than 3.99%. The limits of detection and quantification for AQ were 0.001 and 0.003 mg/kg, respectively. Owing to the good accuracy, precision, and high sensitivity, the proposed method is suitable for the determination of trace AQ in tea. The results demonstrated that AQ was detected in 67.1% of tea samples, with the average concentration of 0.0160 mg/kg. The contamination levels varied from tea types and sale locations. The individual average values of AQ in green tea, black tea, oolong tea, and pu-erh tea products were 0.0161 mg/kg, 0.0140 mg/kg

The article analyzes the main trends and prospects for the development of the global and Russian tea market. It reviews and analyzes the main directions of development of the tea market in the world, provides an international classification of black tea, shows the main countries manufacturers, importers and exporters of this product. The dynamics of tea production, import and export in the Russian Federation over five years showed in this article by using analytical indicators. Also were identified the main reasons for the changes and analyzed the leading players-producers of the domestic tea market, as well as showed the main trends characteristic of the development of this market in immediate prospects. The article considers the general structure of the tea market in natural terms and provides the results of analysis of changes in consumer preferences. Within the framework of the study, the assortment of the Perekrestok retail network was studied as a tool for forming and maintenance commodity stocks of this economic entity. ABC-analysis was used to analyze the assortment of black tea. Based on the results of the study, recommendations were developed and proposed for further work with the assortment of this product group.

Tea (Camelia sinensis L.) is one of the main beverages known and consumed all around the world. Quality of tea is not only linked to the raw material but also to the processing steps that influence on the biochemical and sensory characteristics of each type of tea. This overview is focused on the differences in the production and composition of the main types of teas present in the market, highlighting not only their chemical and sensory characteristics, but also the importance of this plant from the food science viewpoint related to its several applications.

As the most abundant component in black tea, thearubigins (TRs) contribute a lot to black tea's characteristic color, mouthfeel, and potential health benefits. But compared to lower molecular weight black tea polyphenols, there are fewer researches that focus on TRs because of their heterogeneity. This review summarized recent research progress on (1) isolation method of TRs; (2) structure analysis and formation mechanism of TRs; (3) biofunctions of TRs, including antioxidation, antimutagenic and anticancer effects, effects on mitochondrial activation, gastrointestinal motility and skeletal health, to show some future research aspects and prospects of TRs.

Brewed tea is the most consumed beverage after water. The tea commodity is divided into four: bulk green tea, retailed green tea, bulk black tea, and retailed black tea. Eventhough bulk black tea has the lowest price average, it has the highest demand and import value growth each year. Rusia is not only the main export destination country for Indonesian bulk black tea, but also the largest bulk black tea importer in the world. The purpose of this research are to analyze the position of Indonesian bulk black tea export competitiveness in the global market and to find the factors that significantly affect Indonesian bulk black tea export in Russian market. The result of CMSA shows that Indonesia's competitiveness ranks low among other exporter countries and has a negative growth trend. According to multiple linear regression analysis, the most significantly affecting factor is price with a negative relation. Which means when price grows, Indonesia's competitiveness decline.

In the mid-1800s, plantation-produced tea from India came onto the British market. Tea retailers blended this more malty and black tea with the lighter Chinese-grown tea to which consumers had become accustomed. By the turn of the 20th century, blending helped Empire-grown tea supplant Chinese-grown tea on the market. Scholars of tea have shown how British tea companies working in South Asia stoked racialized fears that Chinese tea arrived in Britain in an adulterated state, laden with impurities that included dyes, perfumes and even human sweat. This article describes how concerns about protecting tea leaves from outside adulteration gave way to concerns about the potential digestive threat that lay inside tea leaves themselves. Medical journals linked the increased consumption of Indian teas to a population-wide ‘epidemic’ of indigestion. The most cited culprits in this epidemic were tannins, chemical compounds that were also thought to give black tea its characteristic bitterness and color. The normalization of black tea consumption among the British public was not just a work of marketing or branding but a work of resolving uncertainty about what tannins were at a material, biophysical level. As this uncertainty was resolved scientifically, tea was materialized not as a singular, unified product but as an active chemical assemblage.

The quality of Congou black tea fluctuates greatly with the changing seasons. However, variations in the taste quality of Congou black tea manufactured during a single spring season are far from clear. Here, we analyzed the taste quality of HuangJinCha (HJC) Congou black tea using sensory evaluation and found the taste quality of black tea manufactured in the early spring was better than that manufactured in the late spring. Principal component analysis (PCA) and cluster analysis for the data from the electronic tongue confirmed the variation and revealed that April 4 may be the critical time point at which variations in taste quality become apparent. The contents of tea polyphenols (TP), total catechins (TC), total flavones, (‐)‐epigallocatechin gallate (EGCG), (‐)‐epicatechin gallate (ECG), and gallic acid (GA) showed increasing trends, whereas total amino acids (TAA) declined over time. Moreover, the variations in total amino acids (r = 0.846) and total flavones (r = ‐ 0.858) were highly significantly correlated with the average taste quality score (p, The taste quality of Huangjincha Congou black tea manufactured in the early spring was better than that manufactured in the late spring. The variations in total amino acids and total flavones were significantly correlated with the average taste quality score (P < 0.01), suggesting these two compounds were the primary factors responsible for the fluctuation in taste quality.

Background Rare earth elements (REEs) played an important role in enhancing the yield and quality of tea, and have been widely used in tea cultivation. In the present study, 3011 tea samples of four tea types, namely black tea, green tea, oolong tea and dark tea, were collected from the mainly tea producing areas in different provinces of China to analyze the contents of 16 REEs by inductively coupled plasma mass spectrometry. Results The results obtained showed that the higher average content of REEs was 2.960 mg kg-1 in black tea from Henan province, 2.500 mg·kg-1 in green tea from Shanxi province, 3.870 mg·kg-1 in oolong tea from Guizhou province and 2.955 mg·kg-1 in dark tea from Hunan province. The sum percentage of five elements (Sc, Y, La, Ce, and Nd) to total REEs was 84.39% in black tea, 85.07% in green tea, 83.67% in oolong tea and 84.42% in dark tea. In addition, the content of Ce in tea was greatest, regardless of the province of China. The content trend of the five REEs was Ce > La > Sc > Nd > Y in black and green tea, respectively. However, the content trend was Ce > Y > Sc > Nd > La in oolong tea and Ce > Y > La > Nd > Sc in dark tea. Conclusion The tea leaves mainly accumulated light REEs rather than heavy REEs. These results provided an important theoretical basis for investigation of the accumulation characteristics of REEs in Chinese tea. © 2020 Society of Chemical Industry.

This study aimed to evaluate the effects of tea extracts on oral biofilm colonization depending on steeping temperature. S. mutans and S. sobrinus were cultured and treated with green or black tea ...

Theaflavins (TFs) are generated by endogenous polyphenol oxidase (PPO)- and peroxidase (POD)-catalyzed catechins oxidation during black tea processing, which needs to be well-controlled to obtain a proper TFs/thearubigins (TRs) ratio for better quality. Not all leaves from any tea plant cultivars or varieties are suitable for making high-quality black teas, regardless of the processing techniques. The mechanisms underlying TFs formation and the main factors determining the tea leaf processing suitability are not fully understood. We here integrated transcriptome and metabolite profiling of tea leaves to unveil how enzymes or metabolites in leaves are changed during black tea processing. The information enabled us to identify several PPO and POD genes potentially involved in tea processing for TF production. We characterized a POD gene, whose recombinant enzyme showed TF creation activity. The capacity for POD-catalyzed TF production could be used as a molecular marker for breeding tea plant varieties suitable for high-quality black tea production.

Tea is a non-alcoholic beverage that is widely consumed after water with potential health benefits. In general, tea processing divided into three types, non-enzymatic oxidation process (green tea), semi-oxidation (oolong tea), and with enzymatic oxidation (black tea). The sorting and grading is a stage in controlling the quality of green tea. This study aims to determine the characteristics of different grades of green tea on the total polyphenols, liquor color, and rehydration ratio. The results showed that the pekoe/pecco grade had the highest total polyphenol and rehydration ratio compared to other grades. Pekoe grade has a greenish yellow and brighter liquor color. Application of good agriculture practice (GAP) and plucking of fresh tea leaves should be considered to obtain more grade pekoe in the green tea processing.

Jinjunmei (JJM), Keemun (KM), and Dianhong (DH) are the representative black teas in China, and they have always been favored by consumers. In this study, we aim to obtain the aroma characteristic information of volatile components in black tea samples through headspace solid-phase microextraction (HS-SPME), solvent-assisted flavor evaporation (SAFE), and gas chromatography-mass spectrometry combined with gas chromatography-olfactometry technology. The results showed that 70 compounds including α-methylbenzyl alcohol (isomer of β-phenylethanol) were identified as odorants. Among them, 39 compounds such as linalool and geraniol showed a high degree of aroma contribution. Furthermore, the Feller’s additive model was used to explore the perceptual interactions among the methyl salicylate and the floral compounds (10 groups): five groups of binary compounds showed masking effect after mixing, one group showed additive effect, and four groups showed synergistic effect. The ratio (R) was compared with the aroma index (n) of Steven’s law, which found a high-fitness exponential relationship. The results of this study help to provide additional and new theoretical guidance for improving the aroma quality of black tea.

The formation of prostaglandin E2 (PGE2) is associated with adverse inflammatory effects. However, long-term treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) comes with risk of severe side effects. Therefore, alternative ways to inhibit PGE2 are warranted. We have investigated the effects of tea extracts and the polyphenols epigallocatechin gallate (EGCG) and quercetin on PGE2 formation, determined by immunoassay, and protein expression, determined by immunoblotting, of cytosolic phospholipase A2 (cPLA2), cyclooxygenase 2 (COX-2) and microsomal PGE synthase-1 (mPGES-1) in human monocytes. Green and black tea extracts, and with a lower potency, Rooibos tea extract, inhibited lipopolysaccharide (LPS) and calcium ionophore-induced PGE2 formation. In addition, all tea extracts inhibited the LPS-induced expression of mPGES-1, and the green and black tea extracts also inhibited, to a lesser extent, COX-2 expression. The tea extracts only marginally reduced cPLA2 expression and had no effect on COX-1 expression. EGCG, present in green and black tea, and quercetin, present in all three teas, also inhibited PGE2 formation and expression of mPGES-1, COX-2 and cPLA2. Cell-based and cell-free assays were also performed to evaluate direct effects on the enzymatic activity of COX and PGE synthases. Mainly, the cell-free assay demonstrated partial inhibition by the tea extracts and polyphenols. However, the inhibition required higher doses compared to the effects demonstrated on protein expression. In conclusion, green and black tea, and to a lesser extent Rooibos tea, are potent inhibitors of PGE2 formation in human monocytes, and mediate their effects by inhibiting the expression of the enzymes responsible for PGE2 formation, especially mPGES-1.

The formation of prostaglandin E2 (PGE2) is associated with adverse inflammatory effects. However, long-term treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) comes with risk of severe side effects. Therefore, alternative ways to inhibit PGE2 are warranted. We have investigated the effects of tea extracts and the polyphenols epigallocatechin gallate (EGCG) and quercetin on PGE2 formation, determined by immunoassay, and protein expression, determined by immunoblotting, of cytosolic phospholipase A2 (cPLA2), cyclooxygenase 2 (COX-2) and microsomal PGE synthase-1 (mPGES-1) in human monocytes. Green and black tea extracts, and with a lower potency, Rooibos tea extract, inhibited lipopolysaccharide (LPS) and calcium ionophore-induced PGE2 formation. In addition, all tea extracts inhibited the LPS-induced expression of mPGES-1, and the green and black tea extracts also inhibited, to a lesser extent, COX-2 expression. The tea extracts only marginally reduced cPLA2 expression and had no effect on COX-1 expression. EGCG, present in green and black tea, and quercetin, present in all three teas, also inhibited PGE2 formation and expression of mPGES-1, COX-2 and cPLA2. Cell-based and cell-free assays were also performed to evaluate direct effects on the enzymatic activity of COX and PGE synthases. Mainly, the cell-free assay demonstrated partial inhibition by the tea extracts and polyphenols. However, the inhibition required higher doses compared to the effects demonstrated on protein expression. In conclusion, green and black tea, and to a lesser extent Rooibos tea, are potent inhibitors of PGE2 formation in human monocytes, and mediate their effects by inhibiting the expression of the enzymes responsible for PGE2 formation, especially mPGES-1 Ingick som manuskript i avhandlingen med titeln Cancer and Inflammation: Role of Macrophages and Monocytes

Coffee and tea are popular beverages worldwide, and therefore generate large amounts of waste. Here we describe the caffeine content and phenolic profile in three types of teas and coffees, and how they vary with two successive extractions. Although the first extraction was far more efficient than the second, green tea also showed a high content of flavanols in the second extraction, as did mate tea for phenolic acids. Black tea could also be a good option since caffeine content was highest in both extractions. Water also proved to be the most effective solvent in almost all cases, which represent a major benefit for urban horticulture, as it is a simple extraction method from an easily accessible source. Coffee and tea residues are a rich source of caffeine and phenolic compounds that could potentially be used as alternatives to conventional pesticides.

This study aimed to compare the effect of hot roller (HR) drying and hot air (HA) drying on the sensory evaluation, chemical quality, antioxidant activity, and metabolic profile of Yihong Congou black tea processed from E’cha NO1. The Yihong Congou black tea dried with HA obtained higher sensory scores and better chemical qualities such as the hue of tea brew color (a and b), content of theaflavins, thearubigins, water extract, free amino acids, tea polyphenol, and the ratio of polyphenol to amino acids as well as higher antioxidant capacities compared to that dried with HR. The HA drying tea increased the contents of volatile compounds that had positive correlation with sweet and flowery flavor, while the HR drying tea increased the contents of volatile compounds related to fruity flavor. Moreover, non-targeted metabolomics data indicated that the levels of most free amino acids significantly increased, while the levels of most soluble sugars reduced in the HA drying method compared to the HR drying method. The metabolic analysis was also consistent with the above results and revealed that D-ribose and gallic acid were the main characteristic metabolites of HA drying. Our results could provide a technical reference and theoretical guide to processing a high quality of Yihong Congou black tea.