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This research aims to identify the phytochemical constituents of 79 different samples of black tea, including varieties from India, Iran (IrT), Turkey (TT), and Sri Lanka. In addition, this study investigates the effect of varying brewing times on the quality characteristics of tea. Therefore, we analyzed the phytochemical content of tea using a novel LC–MS/MS method that we developed, which identifies 53 different phenolic compounds. Furthermore, objective evaluations were conducted on the total phenolic compound, total flavonoid compound, antioxidant activity, and color values at 15, 30, and 60‐min brewing intervals. The prevailing phenolic compounds discovered in the corresponding tea classifications were quantitatively analyzed to be quinic acid, epicatechin gallate, epigallocatechin gallate, epicatechin, epigallocatechin, gallic acid, nicotiflorine, and isoquercitrin. The study found that the TT and IrT groups had the richest phytochemical content and the highest antioxidant activity. The Turkish tea group had the highest measurement for the desired red color, which is considered a sensory property. Infusion color, antioxidant activity, and total phenolic and flavonoid contents showed significant increases with prolonged brewing time. It was important to note that the chemical composition of tea varies according to its origin and brewing conditions. Extending the brewing time improved the quality of the tea. It should be noted, however, that longer brewing times result in a more intense release of flavonoids, and this increase may have a pro‐oxidant effect. [ABSTRACT FROM AUTHOR]

Aim: The present study investigated the efficacy of Camellia sinensis regarding its antifungal activity toward Candida albicans and compared the various forms such as Japanese green tea, Chinese Oolong tea, Sabha black tea, and Sri Lanka black tea in relation to their antifungal property toward C. albicans. Materials and Methods: In this in vitro experimental study, the C. albicans were grown and maintained in their respective agar. Four different concentrations of 500 mg/mL and 250 mg/mL aqueous solution; 250 mg/mL ethanolic solution and 250 mg/mL methanolic solutions were prepared from four different forms of C. sinensis such as Japanese green tea, Oolong Chinese tea, Sabah black tea, and Sri Lanka black tea. The Kirby-Bauer disc diffusion method determined the activity of tea. The standard drug of Nystatin 100 IU (international units) was used as the positive control. After an incubation period of 48 h at 37ºC, the zone of inhibition was measured in millimeters. Results: Japanese green tea at its aqueous concentrations of 500 mg/mL and 250 mg/mL exhibited significantly higher mean zone of inhibition of 20.63 mm and 20.92 mm, respectively against C. albicans at P < 0.001. However, a mean zone of inhibition of 21.26 mm was shown by positive control Nystatin. Conclusion: The aqueous extract of Japanese green tea showed higher antifungal activity against C. albicans in comparison to black teas. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate pesticide residues in the imported and domestic tea sold in Turkey and to detect their compliance with maximum residue limits (MRL) and Acceptable Daily Intake (ADI). A total of 79 samples were analyzed by using LC-MS/MS and GC-MS devices with AOAC 2007.01 method to investigate 603 pesticide residues. According to the results, pesticide residues were found in a total of 28 tea samples. Pesticide residues were found in the countries of origin at the rates as follows: Iran (100%), India (33.3%) and Sri Lanka (17.3%). No pesticide residue was detected in the tea produced in Turkey. The compounds such as Diuron, Ethion, Cypermethrin, Thiacloprid, Thiamethoxam, Fenpyroximate, Acetamiprid, Imidacloprid, Flubendiamide, Deltamethrin and Hexythiazox were detected in positive samples. Seven types of pesticide residues exceeded the MRL determined by the Turkish Food Codex for 15 types (53.57%) for 28 samples with pesticide residue detected. Additionally, 4 types of pesticide residues were determined to exceed the ADI determined by the Codex Alimentarius for 13 (46.42%) of 28 samples with pesticide residue detected. These results have showed that the imported tea entering Turkey was not adequately analyzed in the customs control laboratories or the maximum residual limits were not clearly determined. [ABSTRACT FROM AUTHOR]

Black tea extracts (BTEs) from four different production areas showed a higher aggregation strength for phosphatidylcholine-based liposomes containing cholesterol used as a viral membrane model. Furthermore, the anti-influenza A virus (IAV) activity of each BTE in vitro demonstrated that although Sri Lanka, Kenya, and Assam had higher anti-IAV activities, Darjeeling had a lower anti-IAV activity, showing a correlation between each BTE and the liposome aggregation strength. Moreover, the antiviral activity strength of BTEs was consistent with the antioxidant activity strength of BTEs, suggesting that the component(s) in black tea that exhibits antioxidant activity would also be the component(s) that accounts for its antiviral activity. Thus, our results propose that BTEs exert their antiviral effects by binding not only hemagglutinin and neuraminidase but also viral membranes directly, especially "cholesterol-rich lipid rafts" and affect the membrane structure, causing the virus to aggregate, thereby inhibiting infection of the host cells. [ABSTRACT FROM AUTHOR]

Abstract: In order to objectively indicate the bitter taste intensities of black and oolong teas on the basis of a permanent standard point, a taste sensor method was developed that calibrated the sensor outputs with standard solutions prepared with only pure chemicals. Ethyl gallate (EG) was used as the standard substance. The sensor outputs were converted into the bitter taste intensities using two EG solutions at different concentrations. The astringent taste intensities of these teas were evaluated by the similar method. In this case, (−)-epigallochatechin-3-O-gallate (EGCg) was used as the standard substance. These evaluation results by the taste sensor system showed a similar tendency as those by human gustatory sense. Relative standard deviations of the sensor results revealed that these evaluation methods possessed enough practical precisions. Two-dimensional mapping analysis of the bitter and astringent taste intensities showed that, as a whole, the taste intensities of the Indian and Sri Lankan black tea samples had a tendency to be stronger than those of the Chinese oolong tea samples under the sample preparation conditions in this study. [Copyright &y& Elsevier]

Abstract: Ethnopharmcological relevance: Sri Lankan traditional practitioners recommend the consumption of black tea infusion (BTI) made from Camellia sinensis L. plant for regulation of glycaemia. However, they do not specify the grade of tea and their origin (i.e., agroclimatic elevation) and as such many prediabetics and milddiabetics use BOPF grade tea. Aim of the study: This study examines the blood glucose lowering potential of Sri Lankan BOPF grade tea and its potency with respect to agroclimatic elevations. Materials and methods: Unblended orthodox BOPF grade tea samples were collected from high-, mid- and low-grown agroclimatic elevations in Sri Lanka. Different concentrations of warm BTI (60, 120 and 480mg/ml), tolbutamide (reference drug: 22.5mg/kg body weight) and water (control) were orally administered to different groups of rats, and hypoglycaemic and antihyperglycaemic activities were assessed. Antidiabetic activity was determined using streptozotocin induced diabetic rats. Mechanisms of blood glucose lowering actions were investigated using several standards techniques. Results: BTI exhibited significant (P <0.05), dose-dependent and marked hypoglycaemic and antihyperglycaemic activities with quick onset. These effects did not differ with respect to agroclimatic elevation, although there were differences in the content of phyto-constituents. BTI also showed marked and quick antidiabetic activity. BTI inhibited intestinal glucose absorption and impaired α-glucosidase and α-amylase activities. BTI possessed insulinomimetic action, ability to improve insulin sensitivity and in vivo antioxidant activity. Notably, BTI was nontoxic. Conclusions: BTI of Sri Lankan BOPF grade tea has oral hypoglycaemic, antihyperglycaemic and antidiabetic actions which are mediated via multiple mechanisms. This study also indicates that, BOPF grade tea of any agroclimatic elevations in Sri Lanka could be used in the regulation of glycaemia. [Copyright &y& Elsevier]

Abstract: The fluoride contents were determined by ion-selective electrode in 26 black tea samples originally produced in Turkey, Sri Lanka, India and Kenya, and in 14 herbal and seven fruit infusions originated from Turkey. Fluoride content in black tea infusions ranged from 0.57 to 3.72mg/L after 5min of brewing. Higher fluoride levels were found in black teas originated from Turkey when compared with teas originated from Sri Lanka. Moreover higher fluoride levels were determined in black tea bags compared with granular and stick-shaped black teas. However, herbal and fruit infusions were characterized by low values of fluoride (0.02–0.04mg/L) after 5min of brewing and increasing brewing time to 10min caused only slight increases in some infusions. As a result, consuming tea infusions prepared from some black tea available in Turkish market, especially black tea bags, in large quantities may lead to exposion to a high amount of fluoride which may cause dental fluorosis. Although fruit and herbal infusions are safer to consume their fluoride contents are too low for caries prevention. In countries such as Turkey where tea is traditionally consumed, the fluoride concentration and daily safety precautions should be indicated on tea products. [Copyright &y& Elsevier]

This study examined the antidiarrhoeal potential of Sri Lankan black tea (Camellia sinensis) in mice using high grown unblend Dust grade No: 1 tea. Different concentrations of black tea brew (BTB) [84 mg/ ml (equivalent to 1.5 cups), 167 mg/ ml (equivalent to 3 cups), 501 mg/ ml (equivalent to 9 cups) or 1336 mg/ ml (equivalent to 24 cups)], or a high concentration (equivalent to 9 cups) of green tea brew (GTB) of Chinese and Japanese types or reference drug, loperamide (10 mg/ kg) were orally administered to different groups of mice (N = 9-12/group) and were subjected to two antidiarrhoeal tests: normal defecation test and castor oil-induced diarrhoea test. The results show that BTB of Sri Lankan Dust grade tea dose-dependently and markedly decreased the number of faecal boluses produced in the normal defecation test and improved the severity of the diarroheal condition in the castor oil-induced diarrhoea test. However, the antidiarrhoeal effect of BTB was superior to Japanese type of GTB and inferior to loperamide. BTB also prolonged the gastrointestinal transit time, impaired intestinal fluid secretion, increased intestinal fluid absorption and reduced in vitro nitric oxide production. It is concluded that Sri Lankan black tea possesses marked antidiarrhoeal activity supporting the folkloric claim that Sri Lankan black tea is a good remedy for acute non specific diarrhoea. [ABSTRACT FROM AUTHOR]

Abstract: Aim: In Sri Lankan traditional medicine black tea brew (BTB) of Camellia sinensis (L.) O. Kuntze (Theaceae) is claimed to have male sexual stimulant activity. As this claim is not scientifically tested and proven, this study was undertaken to evaluate the effects of BTB on male sexual competence. Material and methods: Different doses of BTB made from Sri Lankan high grown dust grade no 1 tea (84, 167 and 501mg/ml) or water were orally administered to separate groups of rats (n =9 per group) and 3h later their sexual behaviour were monitored (for 15min) using receptive females. Results: The overall results showed that BTB possesses marked aphrodisiac activity (in terms of prolongation of latency of ejaculation shortening of mount- and intromission latencies and elevation of serum testosterone level). The aphrodisiac action had a rapid onset and appears to be mediated via inhibition of anxiety and elevation of serum testosterone level. Further, this aphrodisiac action was not associated with impairment of other sexual parameters like libido, sexual motivation, sexual arousal, sexual vigour or penile erection. BTB was also nontoxic (in terms of overt signs, liver and renal toxicity). Conclusions: It is concluded that BTB can function as a quick acting, safe, oral aphrodisiac which may also be useful in certain forms of sexual inadequacies such as premature ejaculation and impaired libido and other sexual functions. [Copyright &y& Elsevier]

The purpose of this study was to assess the fluoride content of Ceylon Tea, which is a popular beverage throughout the world. The fluoride content of tea infusions prepared from different grades of tea leaves collected from different parts of the tea-growing regions (25 samples) of Sri Lanka was measured using a fluoride-selective electrode. Fluoride leaching was found to vary from 0.32 to 1.69 mg F/l, but there were no significant differences in terms of fluoride leaching between tea from different tea-growing regions or between tea of different grades. Dental fluorosis is widespread throughout the dry zone of Sri Lanka, and drinking water has traditionally been considered to be the main contributory factor to the development of fluorosis. However, diet, the consumption of tea in particular, may also contribute to the manifestation of dental diseases. [ABSTRACT FROM AUTHOR]

Fluoride content in black tea in various commodities, packages, and preparation processess was assayed and its safety evaluated. A fluoride ion selective electrode method was used to determine the fluoride content in 20 tea samples, in various black tea commodities, namely stick-shaped, granular, and canned or bottled tea beverage, originally produced in India, Sri Lanka, China, Japan and UK, and milk–tea after addition of milk and sugar. The fluoride content of 5 stick-shaped black teas was 96.9–148 mg/kg, that of 8 granular black tea was 139–223 mg/kg, and that of 3 canned or bottled beverage black tea beverages was 0.70–0.96 mg/l, respectively. Neither the bagged black tea paper nor the addition of milk and sugar affected the ionic fluoride level within the tea. These results suggest that, for heavy black tea drinkers, the fluoride intake in areas with drinking water fluoridation, and also other probable sources of fluoride, may approach or reach the level of risk from chronic fluoride intoxication. [Copyright &y& Elsevier]

The article discusses the scope and limitation of the taste sensor system for analyzing the astringency of black tea samples manufactured in India and Sri Lanka. According to the results of an organoleptic test, the sensor output was correlative to the human gustatory sense. The authors conclude that the astrigency of black tea can be successfully evaluated by using a 0.65 mM and 0.26 mM epigallocatechin-3-O-gallate aqueous solution including 5 mM KCl as a standard.