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In an industrial context of producing catechin-enriched fractions by electromigration, a new technology demonstrated to be effective for concentration of the two main catechins (EGC and EGCG) of green tea, the recovery yield from tea leaves during brewing would be the most important parameter of the whole process rentability. However, the majority...
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A simple, rapid and reliable method of high performance liquid chromatography (HPLC) was developed for the simultaneous determination of bioactive compounds in oolong teas. The optimized method consisted of the use of a C18 reversed-phase column, an isocratic elution system (2 ml/min) of water:acetonitrile (87:13) containing 0.05% trifluoroacetic a...
A preliminary study on separation of catechins from green teas using a created separation unit consisting of a 1-L column packed with Amberlite XAD-7HP was investigated. Green tea was produced from young fresh shoots and determined for total polyphenols content (TPC), caffeine (CF) and total catechin content (TCC), including (-)-epicatechin (EC), (...
Tea (Camellia sinensis L.) has attracted much attention due to the antioxidant capacities of bioactive compounds present in it, which are considered beneficial to consumer health. In Thailand, commercially cultivated teas are the Assam and the Chinese cultivars which both are processed as green teas. The aim of this study was to investigate the che...
Roasting is crucial for producing Yuan An yellow tea (YAYT) as it substantially affects sensory quality. However, the effect of roasting time on YAYT flavor quality is not clear. To investigate the effect of roasting time on the sensory qualities, chemical components, odor profiles, and metabolic profile of YAYTs produced with 13 min roasting, 16 m...
The optimal brewing conditions for Turkish green tea were determined on the basis of extracted catechins and sensory attributes. Green tea infusions were prepared at 75, 85 and 95 °C with brewing times of 1, 2, 3, 5, 10, 20, 30 and 45 min. The amounts of epistructured catechins (EGCG, EGC, ECG, EC), non-epistructured catechins (C, GC, GCG) and caff...
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... They found that the prolonged effect of brewing red tea increased the content of polyphenolic compounds. Labbe, Tremblay and Bazinet [2006] conducted a study on the content of catechins in tea after the second brewing. Epigallocatechin and epicatechin content decreased after the second brewing, while epicatechin gallate and epigallocatechin gallate content increased. ...
The aim of the research was an attempt to obtain cosmetic care masks containing powdered waste leaves from red and green tea. On the basis of literature reports and our own research, original cosmetic formulas containing the addition of teas and the technology for their manufacture had been developed. Before incorporating the tea raw material into the cosmetic, it was dried to an adequate level of dryness and ground to a powder. The reference point in the evaluation was the base mask (without the addition of teas). Next, the functional properties of the cosmetic prototypes were evaluated. Viscosity, yield point, and skin moisturization were evaluated, and a sensory analysis of the developed masks was carried out. Based on the study, it was found that the masks containing the addition of powdered tea leaves had more favourable rheological and sensory properties, and showed a higher degree of moisturization two hours after washing the product off the skin, relative to the base mask.
... Although TPC slightly increased with infusion time, the difference was not statistically significantly. This finding is in accordance with Labbé et al. [50], who reported that the concentration of phenolics in green tea increased up to a certain level, and then remained constant after a further increase of infusion time. On the contrary, several studies reported that an increase in preparation time favours the extraction of phenolics by increasing their solubility and the diffusion coefficient [51]. ...
The aim of this study was to characterise the elemental and radiological composition of strawberry tree (Arbutus unedo L.) leaves and tea preparations and compare it with commercial Uvin H herbal mixture, widely used in treatment of urinary tract infections. The concentration of 17 elements and the activity concentration of selected radionuclides were measured in strawberry tree leaves/Uvin H herbal mixture, as well as in herbal tea prepared by infusion or decoction of leaves for 5 or 10 min. In both leaves and tea preparations, Ca, K, Mg, and Na were the most abundant elements, while the lowest levels were measured for As, Co, Mo, and Se. Only ¹³⁷Cs and ⁴⁰K were detected in analysed leaves/herbal mixture, while the activity of radionuclides in tea preparations was below the detection limit. The maximum possible health benefits can be obtained by a 10-min decoction of leaves, which resulted in the highest total phenolic content and antioxidant activity and levels of K, Ca, Mg, Na, Fe, Mn, and Se in comparison to the other preparation methods evaluated in this study. The calculated intake of potentially toxic elements and radionuclides does not represent a health risk to consumers.
... p=0.034 respectively) interpretation that older adults may be less likely to use the internet due to factors such as lack of access, lack of interest, or lack of knowledge about how to use the internet [48]. Based on a study by Carolny (2010) showed how drinking tea can steep genes in health, typically one would use water that is not quite boiling, and pour it over the tea, letting the leaves steep for approximately 2 to 3 minutes [49]. In contrast to our study most respondents, 38%, preferred to boil their green tea for 10 minutes. ...
Green tea is one of the most widely consumed beverages worldwide, with green tea gaining popularity due to its potential health benefits. Consuming too much green tea daily could have adverse effects. Following the consumption of a high dose of green tea extract, several complications and negative effects can be observed, The consumption patterns and habits of the consumer in the tea market are influenced by a variety of factors, including psychological factors behavioural factors and descriptive factors in marketing. A cross-sectional study was conducted among 500 participants selected randomly from different areas in Benghazi, Libya. A validated questionnaire assessed demographics, knowledge, attitude, and practices about green tea. Five commonly consumed green tea brands were selected from local markets and brewed for different durations (soaking, 10, 20, 30, 60) minutes at a constant temperature of 100. Samples were analysed for physicochemical parameters and compared with Libyan standard specifications for green tea. The relationship Between Socio-Demographic Factors and Knowledge, Attitude, and Practice About Original Research Article Alojaly et al.; Asian J. 733 Green Tea, was modelled using the statistics package social sciences (SPSS). There was a significant relationship between the number of times people drink green tea and income (p=0.021). Also, there was an association between believing green tea is good for children and education level (p=0.000). The standard requirements and explanatory data of the sample were close to the standard specification for tea. The studied samples achieved a good level of quality in all measured physical and chemical properties compared to the Libyan standard specification for tea. When analysing the samples, it was noticed that the caffeine values in all samples increased with brewing duration. While the value of tannin in green tea reached the highest concentration value at 20 minutes, except for sample E, at 30 minutes, Most participants were aware of the health benefits of green tea but lacked knowledge of its potential side effects. There is a high level of children who don't drink green tea. Tea sample quality varied from brand to brand according to parameters like moisture, ash, and fibre content. Caffeine content increased with longer brewing time, and tannin content started to decrease when brewed for more than 20 minutes.
... The main tea catechins are catechin (C), gallocatechin (GC), epicatechin (EC), epicatechingallate (ECG), epigallocatechin (EGC), and epigallocatechingallate (EGCG) [6]. Catechins affect the color, aroma, and taste [7,8]. ...
This study was conducted to obtain a clear product and enhance the product quality by reducing or preventing the formation of tea cream, one of the most critical problems in ready to drink (RTD) tea production. Thus, the tannase enzyme was applied to the Turkish black tea extracts at by different brewing temperatures (50 and 70 °C), times (5, 10, and 20 min), and tea:water ratios (1:100, 5:100, 10:100). Total phenolic, tea cream and catechin analysis were performed on the extracts. The amount of tea cream was in the range of 0.37–0.74 g/100 g black tea in the enzyme-treated samples and 1.23–2.19 g/100 g black tea in the untreated control sample. Moreover, a decrease in the cream in black tea extracts obtained using the classic extraction method was observed at around 65.89–74.55% with the tannase enzyme application.
... Apigenin is rich in dried parsley, with a concentration of 45,035 µg/g, while EGC and EGCG, which are both types of catechin, can be found in green tea [82]. In addition, EGC was found at a concentration of 1160.6 µg/mL, while the concentration of EGCG was 542.6 µg/mL, when green tea was brewed for 80 min at 50 • C, suggesting green tea as a potent source of flavonoids [83]. Green tea is mainly consumed in Asian countries, such as China, Japan, Korea, and India; this indicates a relationship between green-tea consumption and the relatively low frequency of NB in all of Asia, although this proposition requires further research [84,85]. ...
Neuroblastoma (NB) is an extracranial tumor of the peripheral nervous system arising from neural crest cells. It is the most common malignancy in infants and the most common extracranial solid tumor in children. The current treatment for high-risk NB involves chemotherapy and surgical resection followed by high-dose chemotherapy with autologous stem-cell rescue and radiation treatment. However, those with high-risk NB are susceptible to relapse and the long-term side effects of standard chemotherapy. Polyphenols, including the sub-class of flavonoids, contain more than one aromatic ring with hydroxyl groups. The literature demonstrates their utility in inducing the apoptosis of neuroblastoma cells, mostly in vitro and some in vivo. This review explores the use of various polyphenols outlined in primary studies, underlines the pathways involved in apoptotic activity, and discusses the dosage and delivery of these polyphenols. Primary studies were obtained from multiple databases with search the terms "neuroblastoma", "flavonoid", and "apoptosis". The in vitro studies showed that polyphenols exert an apoptotic effect on several NB cell lines. These polyphenols include apigenin, genistein, didymin, rutin, quercetin, curcumin, resveratrol, butein, bisphenols, and various plant extracts. The mechanisms of the therapeutic effects include calpain-dependent pathways, receptor-mediated apoptosis, and, notably, and most frequently, mitochondrial apoptosis pathways, including the mitochondrial proteins Bax and Bcl-2. Overall, polyphenols demonstrate potency in decreasing NB proliferation and inducing apoptosis, indicating significant potential for further in vivo research.
... El incremento de la relación solvente:hoja acelera la extracción. El valor del coeficiente de difusión rápida para CA se incrementa 9,3 veces pasando la relación de 4 a 10, para UA se incrementa por 7,3 y para OA en una relación de 3,8 para un incremento de la relación de 4 a 8. (Labbé et al., 2006). De acuerdo a la respuesta de la solubilización de los componentes a la temperatura y al tiempo los compuestos fueron divididos en dos grupos: lo que eran dependientes del tiempo y aquellos que eran dependientes del tiempo y la temperatura. ...
... La infusión de la cafeína es ligeramente influenciada por la temperatura y se incrementa moderadamente con el tiempo de extracción. La concentración de la cafeína en el extracto alcanza un máximo a los 40 minutos para todas las temperaturas, a 50 °C la concentración se incrementa lentamente desde 147,8 g/ml a los 5 minutos hasta 331,7 g/ml a los 40 minutos y luego permanece constante, de acuerdo a los resultados de Labbé et al. (2006) las mejores condiciones para la extracción de cafeína son una temperatura entre 70 y 90 °C y una duración entre 20 y 40 minutos. ...
... Figura IV.7: Concentración de los diferentes componentes en función del tiempo y de la temperatura (Labbé et al, 2006) Estas características pueden ser importantes desde el punto de vista industrial dado que se pueden utilizar las condiciones de extracción para producir fracciones enriquecidas en determinadas catequinas de acuerdo con las condiciones de tiempo y temperatura que se utilicen en la operación. ...
Tesis doctoral Universidad de Buenos Aires cinética y equilibrio de extracción acuosa de yerba mate
... Authors also indicated that the relative amounts of caffeine were not changed after tannase treatment. Labbe et al. (2006) investigated the effects of brewing temperature and time on solubility of green tea catechins and reported the best extraction conditions for green tea extracted at 1:50 tea: water ratio as 70-80 ºC and 20-40 minutes. It was also reported that caffeine solubility slightly increased with increasing brewing temperature and caffeine concentration merely influenced by brewing temperature. ...
... Lu et al. (2009) reported increasing EGC concentrations of green tea supplemented with tannase enzyme at different concentrations due to enzymatic hydrolysis. Labbe et al. (2006) reported that solubility kinetics of catechins varied based on brewing time and temperature and achieved the best EGC yield at 50°C and 20-40 minutes brewing times. ...
... Lu et al. (2009) reported decreasing EGCG concentrations of green tea supplemented with tannase enzyme at different concentrations due to enzymatic hydrolysis. Labbe et al. (2006) reported EGCG content at 50 °C brewing temperature and 5, 20 and 40 min brewing times respectively as 15.5, 245.3 and 489.3 µg/ml, the values at 90 °C brewing temperature and 5, 10 and 40 minutes brewing times were respectively reported as 489.6, 763.8 and 1071.4 µg/ml. ...
This study was conducted to investigate the changes encountered in water soluble dry matter (ºBrix), total phenolics, caffeine and some important catechins of green tea extracts extracted through ultrasound-assisted extraction procedures. Extractions were conducted at 70°C temperature, different tea: water ratios (5:100; 10:100) and brewing times (5, 10 and 20 min) and resultant extracts were also supplemented with tannase enzyme. Total phenolics of green tea extracts varied between 2.68 - 3.87 g GAE/100 g dry green tea. The greatest total phenolics (3.87 g GAE/100 g dry green tea) was obtained from 20 min brewing at 70°C and 10:100 tea: water ratio of tannase enzyme-supplemented extract. As compared to the control samples, decreasing EGCG and ECG contents and increasing EGC and EC contents were observed with tannase enzyme supplementations.
... Maximum absorption (nm) 273 nm (Farhan et al., 2016) Melting and boiling point (°C) 218°C, 909.00-910.00°C (Bartosikova & Necas, 2018) Physical description Solid, colorless, bitter, and astringent taste (Bartosikova & Necas, 2018) Crystallization From water (Labbé et al., 2006) Optical rotation (α) 20 −179° (c 0.28 in ethanol) (Labbé et al., 2006) Chemical properties Solubility Time, temperature, and solvent dependent (Hu et al., 2009;Labbé et al., 2006) Soluble in water (Bartosikova & Necas, 2018) Soluble in acetone, ethanol, pyridine, tetrahydrofuran, and methanol (Bartosikova & Necas, 2018) Partially soluble in grease Binding Oxygen Stable under a low partial pressure of oxygen (Zeng et al., 2018) (Continues) ...
... Maximum absorption (nm) 273 nm (Farhan et al., 2016) Melting and boiling point (°C) 218°C, 909.00-910.00°C (Bartosikova & Necas, 2018) Physical description Solid, colorless, bitter, and astringent taste (Bartosikova & Necas, 2018) Crystallization From water (Labbé et al., 2006) Optical rotation (α) 20 −179° (c 0.28 in ethanol) (Labbé et al., 2006) Chemical properties Solubility Time, temperature, and solvent dependent (Hu et al., 2009;Labbé et al., 2006) Soluble in water (Bartosikova & Necas, 2018) Soluble in acetone, ethanol, pyridine, tetrahydrofuran, and methanol (Bartosikova & Necas, 2018) Partially soluble in grease Binding Oxygen Stable under a low partial pressure of oxygen (Zeng et al., 2018) (Continues) ...
... Maximum absorption (nm) 273 nm (Farhan et al., 2016) Melting and boiling point (°C) 218°C, 909.00-910.00°C (Bartosikova & Necas, 2018) Physical description Solid, colorless, bitter, and astringent taste (Bartosikova & Necas, 2018) Crystallization From water (Labbé et al., 2006) Optical rotation (α) 20 −179° (c 0.28 in ethanol) (Labbé et al., 2006) Chemical properties Solubility Time, temperature, and solvent dependent (Hu et al., 2009;Labbé et al., 2006) Soluble in water (Bartosikova & Necas, 2018) Soluble in acetone, ethanol, pyridine, tetrahydrofuran, and methanol (Bartosikova & Necas, 2018) Partially soluble in grease Binding Oxygen Stable under a low partial pressure of oxygen (Zeng et al., 2018) (Continues) ...
Epigallocatechin gallate (EGCG), a green tea catechin, has gained the attention of current study due to its excellent health‐promoting effects. It possesses anti‐obesity, antimicrobial, anticancer, anti‐inflammatory activities, and is under extensive investigation in functional foods for improvement. It is susceptible to lower stability, lesser bioavailability, and lower absorption rate due to various environmental, processing, formulations, and gastrointestinal conditions of the human body. Therefore, it is the foremost concern for the researchers to enhance its bioactivity and make it the most suitable therapeutic compound for its clinical applications. In the current review, factors affecting the bioavailability of EGCG and the possible strategies to overcome these issues are reviewed and discussed. This review summarizes structural modifications and delivery through nanoparticle‐based approaches including nano‐emulsions, encapsulations, and silica‐based nanoparticles for effective use of EGCG in functional foods. Moreover, recent advances to enhance EGCG therapeutic efficacy by specifically targeting its molecules to increase its bioavailability and stability are also described.
Practical applications
The main green tea constituent EGCG possesses several health‐promoting effects making EGCG a potential therapeutic compound to cure ailments. However, its low stability and bioavailability render its uses in many disorders. Synthesizing EGCG prodrugs by structural modifications helps against its low bioavailability and stability by overcoming premature degradation and lower absorption rate. This review paper summarizes various strategies that benefit EGCG under different physiological conditions. The esterification, nanoparticle approaches, silica‐based EGCG‐NPs, and EGCG formulations serve as ideal EGCG modification strategies to deliver superior concentrations with lesser toxicity for its efficient penetration and absorption across cells both in vitro and in vivo. As a result of EGCG modifications, its bioactivities would be highly improved at lower doses. The protected or modified EGCG molecule would have enhanced potential effects and stability that would contribute to the clinical applications and expand its use in various food and cosmetic industries.
... However, as the extraction time increased, the TPC extraction was increasing (p < 0.05); while TF quantification indicated that long-time process is inadequate for their extraction. Labbé et al. (2006) indicated that catechin, the majoritarian flavonoid presented in habanero pepper (Oney-Montalvo et al., 2020), is higher affected by the time of extraction, reducing its value by approximately 5% when extraction time increased from 40 to 80 min. For a better interpretation of the second-order response surface models, selected 3D plots of TF, TPC, TC, AC, and RP as a function of solid-to-solvent ratio (x 1 ) and temperature (x 2 ) are presented in Figure 2. The optimal extraction condition for bioactive compounds, AC, and RP is also presented in Table 3. ...
Habanero pepper is a good source of bioactive compounds with antioxidant capacity; however, up to now, some factors for increasing their extraction have not been investigated yet. This research aimed to evaluate the effect of solid‐to‐solvent ratio (1:250, 1:45, and 1:25 w/V), temperature (20, 35, and 50°C), and time (6, 15, and 24 h) on the extraction of bioactive compounds and antioxidant capacity from habanero pepper following a Box‐Behnken design. The optimal extract was evaluated in its capsaicinoids content by HPLC and as an antimicrobial against two foodborne pathogens. The response surface models adequately adjusted (R2>0.75) experimental data of bioactive compounds extraction from habanero pepper in the ranges of the variables proposed. Extract obtained under the optimal conditions (1:250 w/V, 50°C, and 24 h) contains 1617.9 mg/100g and 628.0 mg/100g of capsaicin and dihydrocapsaicin, respectively, showing a reduction of 1.23±0.14 and 2.37±0.10 log cycles for S. Typhimurium and S. aureus, respectively.
... For instance, Lin, et al. (2008) discovered that after lyophilized and prepared into the same concentration (5 mg/mL), the green tea extracts from cold brewing (4 • C/24 h) performed more effective scavenging on DPPH and hydroxyl radicals as well as more potent chelating on ferrous ions than the extracts of hot brewing (90 • C/20 min) [6]. Additionally, because of the different interdependence between brewing duration and brewing temperature on various tea compounds [7], the tea compositions may eventually exist in dissimilar ratios in the cold and hot-brewed tea infusions, and this may result in their distinct sensory qualities. Therefore, even if made from the same loose tea, sensory characteristics of the tea infusions resulting from different temperature/time extractions may not be simply standardized by adjusting their water content. ...
The market size of varied carbonated teas and bottled ready-to-drink tea products in Taiwan has surpassed that of traditional Taiwan tea with hot infusion. The consumption behavior of Taiwanese consumers for new and varied types of cold infusion tea products has also differed from that of traditional hot infusion ones. More kinds of Taiwan tea with different fermentation levels are gradually being used as raw materials for various cold infusion tea products. Therefore, to study consumers’ responses towards cold-brewed tea has become more important for the market of tea in Taiwan. This study recruited Taiwanese consumers to taste seven Taiwanese specialty tea infusions with various degrees of fermentation, and their opinions were gathered by questionnaires composed of check-all-that-apply (CATA), and temporal check-all-that-apply (TCATA) questions and hedonic scales. We found that both CATA and TCATA data agreed that the sensory features of unfermented and lightly semi-fermented tea infusions could be plainly distinguished from the ones of heavily semi-fermented and fully fermented teas based on correspondence analyses. Through CATA and TCATA, the sensory characteristics of the cold-brewed tea of various fermentation degrees could be clearly identified. The first-hand information of cold tea beverages analyzed through this study could be useful for the development of the market in Taiwan. The proper level of bitterness, astringency, fresh tea leaf flavor, and late sweetness were the essential qualities of cold infusions brewed from lightly fermented teas, which could be the best raw materials for production of cold tea beverages to satisfy as many consumers as possible.