Tea Tannin Research Articles

The Relationship of Tea Consumption Habits with Incidences of Anemia in Adolescent Girls at Pekanbaru City

Anemia is a condition where there is a lack of red blood cells below normal, one of which is caused by consuming iron inhibitors such as tannins in tea. Tannins are known to inhibit the absorption of iron, especially the heme non-iron category. Drinking tea at the same time as eating can inhibit the absorption of Fe and thus affect hemoglobin levels. This study aims to determine the relationship between tea consumption habits and the incidence of anemia in young women at MTsN 3 Pekanbaru. This type of research is descriptive with a cross sectional design. The research sample of 64 female adolescent respondents was obtained using purposive sampling. Sampling used inclusion and exclusion criteria. Data on tea consumption habits was obtained using the SQ-FFQ (Semi-Quantitative Food Frequency) method and using a questionnaire. Hemoglobin level data was obtained by taking blood using the Diaspect device. The results of the study showed that 68,8% of respondents drank tea at the same time as eating, the percentage of respondents who consumed tea in the occasional category if the score was ≥ 10-14,9 with a frequency of 1-2x/week was 53,1% and the percentage of respondents who have a hemoglobin level of ≥12 g/dl with a category of no iron deficiency anemia of 65,5%.The conclusion of this studyis that there is no significant relationship between the habit of drinking tea and the incidence of anemia but there is a significant relationship between the time of tea consumption and the incidence of anemia in Adolescent girls. Keywords : Tea Consumption, Anemia incidence, Adolescent girls.

In-situ growth of SrTiO3 nanosheets on graphene oxide for colorimetric detection of tannins in tea and behavior of active oxygen radicals in the nanozymatic process

Nanozymes are ideal materials for designing colorimetric sensors, and the spontaneous catalytic effect in most of nanozymes commonly leads to instability of the colorimetric signal. To improve this limitation, photoresponsive nanozymes as a switch under specific-light irradiation are used to regulate the reaction process in a controlled manner. Strontium titanate (SrTiO3) is a high-performance photocatalyst, whose heterojunctions formed with reduced graphene oxide (rGO) are promising to efficiently induce the separation of carriers, further generating abundant radicals to colorize the substrate. Here, the SrTiO3-rGO composites with a high specific surface area were synthesized by hydrothermal method and showed excellent peroxidase-like activity under ultraviolet irradiation. The affinity for 3,3′,5,5′-tetramethylbenzidine is equivalent to 19 times that of horseradish peroxidase and the reaction mechanism is analyzed based on reactive intermediates(·O2-) and elemental valence changes. A colorimetric sensor based on SrTiO3-rGO with high sensitivity, low limit (56 nM), and wide linear range (1–100 µM) is constructed for detecting tannins in tea samples. This visualization model provides a reliable idea for the quantitative analysis of trace substances.

A novel tannase from Klebsiella pneumoniae KP715242 reduces haze and improves the quality of fruit juice and beverages through detannification

The presence of high tannin content in fruit juices and other beverages generates bitterness and haze formation with a concomitant deterioration of their quality. This problem could be circumvented by treating these food products with the enzyme tannase (tannin acyl hydrolase EC 3.1.1.20), which contains the ability to hydrolyze the ester and depside linkages present in hydrolyzable tannins. In the present study, a low molecular weight (38.20 kDa) tannase purified from Klebsiella pneumoniae KP715242 was used for clarification and detannification of orange juice, beer, and tea cream solubilization. The initial tannin content of orange juice was reduced to 42.45% upon treatment with 4.5 U/mL of purified tannase at 35°C for 3.5 h. Beer haze was clarified by incubating the colloidal suspension with the purified enzyme. Under the optimum condition of temperature (30°C), incubation time (3.5 h), and enzyme concentration (4.5 U/mL), the initial tannin content of beer was reduced to 46.47%. Tea cream solubilization was achieved by treating the tea extract with varying enzyme concentrations at different time intervals and temperatures. The maximum reduction in the tea tannin content (55%) was observed at 35°C when the enzyme was incubated for 3 h at a concentration of 6.0 U/mL. The results of this investigation could be further exploited at an industrial scale in the detannification of fruit juice, beer, and tea.

INFLUENCE OF THE ADDITION OF CHAMOMILE ON THE CONTENT OF TANNINS IN TEA

In this work, the influence of chamomile on the content of tannin in the blended green and black teas is investigated by the titrimetric method, which relies on the assessment of tannin oxidation by potassium permanganate with the indicator indigo carmine. The standard procedure of titration was altered in such a way that the dilution of filtrate used during the investigation was decreased by 10 times. This modification made it possible to use the regular 250 ml flasks instead of big and inconvenient porcelain bowls. This way, identification of the point of equivalence became easier and more accurate. Application of this modified method to the determination of tannin in a series of blended teas showed results that are in good agreement with those obtained by the standard methods. They proved that the content of tannin in tea does not depend on the added chamomile and, therefore, this herb does not depress the medical value of the investigated blended teas.

PROTEIN PRECIPITATION BY TEA POLYPHENOLS, IN-SILICO ANALYSIS OF ITS BIOAVAILABILITY, AND BINDING TO SARS-COV-2

This study is undertaken to see precipitation of protein non-specifically by tannin in tea, a plant secondary metabolite. Tannins that are present as a part of the defense system of the plant get oxidized to its quinone/semiquinone state and readily react with protein to form a precipitate. In this study, we have estimated the polyphenol content of Assam tea which was decreased by 9.33% due to the precipitation reaction with BSA. We have visualized the precipitation of protein by tannin/polyphenol. In our studies, we have tried to remove highly reactive or protein precipitating polyphenols from ready-to-drink black tea with the help of charcoal beads. Bioavailability, including absorption, metabolism, distribution, and excretion of different types of tea polyphenols in the human body have been assessed using bioinformatics methods. Polyphenols are high molecular weight compounds and are less absorbable through the GI tract. We have also analyzed the binding affinity of 24 tea molecules to spike glycoprotein of SARS -CoV-2.

Implementation of Statistical Process Control Method and Root Cause Analysis on Quality of Bitter Tannin Tea Tin

The purpose of this study was to determine the quality control of tannin content of Bitter Liquid Tea (TCP). This study methodology is quantitative method with statistical process control method and root cause analysis approach. Based on the calculation and analysis of the control chart - p it can be seen that the tannery content of bitter liquid tea (TCP) in a state of uncontrollable. This can be demonstrated by the existence of data points outside the control limit (out of control) on the control chart-p and the point fluctuates very high and irregular, so it can be concluded that the process in a state of uncontrollable. Based on the results of analysis by using root cause analysis showed that the cause of variation in tannin content is the duration of brewing and the amount of dry tea. This result can be used by XYZ Company to assist in improving the quality of tannin in bitter liquid tea, so indirectly the quality of the product also increases. To increase knowledge about Statistical Process Control and Root Cause Analysis method application to improve product quality. This research is a direct implementation to the tea company, so that in accordance with the problems and applicative in providing solutions. The existence of new methods for the company in improving the quality of its tea products.

Tannin-controlled micelles and fibrils of κ-casein

Effects of green tea tannin epigallocatechin-gallate (EGCG) on thermal-stress-induced amyloid fibril formation of reduced carboxymethylated bovine milk protein κ-casein were studied by dynamical light scattering and small angle X-ray scattering (SAXS). Two populations of aggregates, micelles, and fibrils dominated the time evolution of light scattering intensity and of effective hydrodynamic diameter. SAXS experiments allowed us to resolve micelles and fibrils so that the time dependence of the scattering profile revealed the structural evolution of the two populations. The low-Q scattering intensity prior to an expected increase in time due to fibril growth shows an intriguing rapid decrease, which is interpreted as the release of monomers from micelles. This phenomenon, observed both in the absence and in the presence of EGCG, indicates that under thermal stress free conditions, native monomers are converted to amyloid-prone monomers that do not form micelles. The consumption of free native monomers results in a release of native monomers from micelles because only native proteins participate in micelle-monomer (quasi)equilibrium. This release is reversible, indicating also that native-to-amyloid-prone monomer conversion is reversible as well. We show that EGCG does not bind to protein in fibrils, neither does it affect/prevent the proamyloid conversion of monomers. EGCG hinders the addition of monomers to growing fibrils. These facts allowed us to propose the kinetics model for EGCG-controlled amyloid aggregation of micellar proteins. Therein, we introduced the growth-rate inhibition function, which quantitatively accounts for the effect of EGCG on the fibril growth at any degree of thermal stress.

The Relationship Of Drinking Tea Behavior With Levels Of Hemoglobin in STIKes Guna Bangsa Yogyakarta Students

Iron has an important role in the body that functions to transport oxygen from the lungs to all body tissues through hemoglobin in the blood. Iron deficiency is one of the factors causing anemia. Anemia can be diagnosed from a level of hemoglobin. If a person's has Hb level is low, it can be said that the person is suffering from anemia. The low Hb level can be influenced by several factors, one of which is the consumption of tea. The content of tannins in tea can reduce iron absorption by the body. This study aims to analyze the relationship between drinking of tea behavior in STIKES Guna Bangsa Yogyakarta students with level of hemoglobin. The method is carried out by direct interviews with 55 samples of female students and level of henoglobin were checked using the Hb meter automatic. The results obtained were that 71% of the samples consumed tea and 29% did not consume tea. 53.85% of the sample who consumed tea had a low Hb level whereas 68.75% of the samples that did not consume tea had normal Hb levels. Data from the results of chi-square analysis obtained a value of p = 0.001 <0.05, which means that there is a relationship between the behavior of tea drinking with hemoglobin levels in STIKES students for Yogyakarta

Effect of phenolics on amandin immunoreactivity

Amandin immunoreactivity was assessed using monoclonal antibody (mAb) 4C10-based immunoassays: enzyme-linked immunosorbent assay (ELISA), Western blot, and dot blot. Nonpareil almond soluble proteins mixed with equal amounts of select phenolic compounds were incubated at room temperature (RT, 22 °C) or heated at 100 °C for 1 h. As revealed by ELISA, only incubation with tea tannins had a measurable effect on amandin immunoreactivity at RT. Incubation with tannic acid, tannin, ellagic acid, tea tannin, and walnut tannin at 100 °C for 1 h stabilized amandin immunoreactivity. Nonpareil whole almond flour mixed with ellagic acid or grape seed tannins (each at 1 and 2%; w/w) was subjected to autoclaving (121 °C, 15 psi; 5, 30 min); blanching (100 °C, 3, 10 min); microwaving (500 W, 1, 3 min); and roasting (140 °C, 170 °C, 177 °C for 30, 20, and 12 min; respectively). In addition, Nonpareil whole almond flour mixed with ellagic acid or grape seed tannins (each at 1 and 2%; w/w), in presence of sugar (5% and 20%, w/w) or corn syrup (5% and 20%, w/w), was also subjected to roasting at 170 °C for 20 min. ELISA results suggested that moist heat (autoclaving and blanching) was the most effective in reducing the mAb 4C10 detectable amandin immunoreactivity.

Self-Assembled Tea Tannin Graft Copolymer as Nanocarriers for Antimicrobial Drug Delivery and Wound Healing Activity.

Green chemistry polymers from renewable resources have recently received much more attention from pharmaceutical researchers. However, the appropriate application of a polymer depends on its chemical nature, biocompatibility and microstructure. Here, tannin polyphenols from the common beverage, tea, are used to develop a novel self-assembled porous capsule as a microstructure of hydrogel for versatile biological applications, such as drug delivery, antioxidant and wound healing activity. Hydrogel has been successfully used for the delivery of both anticancer and antimicrobial drugs. The developed material shows excellent biocompatibility and antioxidant activity in vitro. The scratch assay for in vitro wound healing activity reveals their higher potential to repair the damaged cells in comparison to control.

Chronoamperometric evaluation of the antioxidant capacity of tea on a polyquercetin-modified electrode

It was established that the components of tea are oxidized on a glassy carbon electrode modified with carbon nanotubes and electropolymerized quercetin in a phosphate buffer solution (pH 7.0) as a supporting electrolyte under conditions of differential pulse voltammetry. The oxidation potentials of the individual phenolic antioxidants of tea (gallic acid, rutin, quercetin, catechin, epigallocatechin gallate, and tannin) on the modified electrode were found. A method for the chronoamperometric determination of the antioxidant capacity (AOC) of tea was developed based on the oxidation of tea antioxidants at a potential of 0.20 V. The AOC of tea was evaluated using а difference between the oxidation currents of the analyte and a supporting electrolyte after 50 s of electrolysis in terms of gallic acid. The analytical range of gallic acid was 0.25‒750 μM with a detection limit of 0.063 μM. Positive correlations of the AOC with antioxidant activity in a reaction with 2,2-diphenyl-1-picrylhydrazyl and the total phenolic content were found (r = 0.700 and 0.647 at r crit = 0.396, respectively).

Determination of pesticide multi-residues in green tea using a modified QuEChERS extraction and liquid chromatography tandem mass spectrometry technique

A modified QuEChERS method was developed and validated for determination of pesticide multi-residues in green tea by liquid chromatography tandem mass spectrometry. Lead acetate was first time used together with primary secondary amine and graphite carbon black to eliminate tannin, caffeine, and other pigments in tea and thus reduced the matrix effects. The method was compared to the original QuEChERS method as well as A.O.A.C. QuEChERS method. For accurate quantification, the matrix matched calibration technique was used. The method showed good performance in the concentration range from 0.01 to 1 mg kg–1. All pesticides could be quantified at and lower than 0.01 mg kg–1. Recoveries were from 70 to 120% and repeatabilities were <15% RSD depending on the compounds.

ВЛИЯНИЕ ФЕРМЕНТАЦИИ И ИЗМЕНЕНИЯ КИСЛОТНОСТИ СРЕДЫ НА СОСТАВ И АНТИОКСИДАНТНУЮ АКТИВНОСТЬ ВОДНЫХ ЭКСТРАКТОВ ЧАЯ

The presense of hydrolysable tannins in green tea, as well as hydrolysable and condensed tannins in black tea has been prooved with the help of potentiometric method, and condensed compounds take 70% of the total content. Antioxidant activity of tea extracts with different type of fermentation has been measured using amperometric method and determined, that the samples of green tea have the highest value of activity. Correlation between the total amount of polyphenols in tea and antioxidant activity was found. There was established, that decrease of pH lowers the quantity of tannins, which take part in oxidation-reduction processes, what may have a connection with their transformation into non-ionized form.

Reference Flow Injection Analysis of Trace Amounts of Tannin with Inhibited Kinetic Spectrophotometric Detection

A simple and highly sensitive reference flow injection inhibited kinetic spectrophotometric method is proposed for the determination of trace tannin in tea and wine samples. The method was based on the enhanced sensitivity of cetylpyridinium bromide on the redox reaction between Eosine Y and KBrO3, and on inhibitory effect of tannin on the same reaction in the sulphuric acid medium. The resulting red complex product was stable in sulphuric acidic medium and has a maximum absorption at 540 nm. The linear response range and detection limit are 0.010-0.45 mg L-1and 4.82μg L-1respectively. The sampling frequency was 20 samples per hour. The relative standard deviation for 11 determinations of 0.10mg L-1tannin acid was 1.78% and values of recovery in the rang of 96.7%-107.3%.The proposed method has been successfully used to determine tannin in tea and wine samples. The results obtained were compared with those provided by the FolinDenis method.

A digital image-based micro-flow-batch analyzer

This paper introduces for the first time the combination of digital images taken with a webcam and a micro-flow-batch analyzer as a novel strategy for implementing quantitative chemical analysis. The digital image-based micro-flow-batch analyzer (DIB-μFBA) was formed using urethane-acrylate resin, glass slides and ultraviolet lithography. The glass slides were used as sealant layers on both sides of the substrate urethane-acrylate and provide the necessary transparency to the microsystem to conduct studies using digital images. DIB-μFBA uses digital images obtained from a webcam with CCD sensor, based on the RGB (red–green–blue) color model. The analyzer was used for determining the tannins in green tea employing the well-known ferrous tartrate method. All standard solutions were prepared in-line, and all analytical processes were completed by simply changing the operational parameters in DIB-μFBA control software. The paired t test, at a 95% confidence level, showed no statistically significant differences between results obtained by DIB-μFBA and the spectrophotometric reference method. The proposed microsystem presented satisfactory physical and chemical properties while keeping the flexibility, versatility, robustness and multi-task characteristics of conventional flow-batch analysis. Therefore, it was possible to build a low-cost device with high sample throughput (about 190h−1) and reduced reagent consumption (about 300 times less than the reference method), contributing to the basic principles of green chemistry and the advancement of micro-analytical procedures.

Antibacterial and antioxidant activities of tannins extracted from agricultural by-products

This study was aimed at evaluating antibacterial and antioxidant activity of tannins extracted by several solvents from agricultural by-products, including green tea waste and acorn, chestnut, and persimmon hulls. Tannin content was the highest in acetone extracts from all types of hulls, but not green tea waste (p<0.05). Tannin extracts from green tea waste had higher antibacterial activity than those from acorn, chestnut, and persimmon hulls extracted with distilled water, ethanol, or acetone. With ethanol extraction, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of green tea tannin extracts was significantly higher than that of tannins extracted from acorn, chestnut, and persimmon hulls (p<0.05). In particular, tannins extracted from green tea waste had a greater IC50 value for DPPH scavenging activity than did vitamin C. Antioxidant activity was also significantly higher in ethanol extracts from green tea waste than in distilled water and acetone extracts (p<0.05). Therefore, tannins extracted from green tea waste could be a natural source for substitutes to present antioxidants as well as antibiotics. Key words: Acorn, antibacterial activity, antioxidant activity, chestnut, green tea, persimmon.

Turbidimetric and photometric determination of total tannins in tea using a micro-flow-batch analyzer

Both turbidimetric and photometric determinations of total tannins in samples of green and black tea, using a micro-flow-batch analyzer (μFBA) were studied. The miniaturized system was formed using photocurable urethane-acrylate resin and ultraviolet lithography technique. The turbidimetric method was based on the precipitation reaction of Cu (II) with tannins in acetate medium at a pH of 4.5. The photometric method was based on the complexation reaction of tannins with ferrous tartrate. The turbidimetric μFBA was able to test 200 samples per hour. The photometric μFBA allowed 300 analyses per hour, generating 136μL of residue per analysis. The paired t test, at a 95% confidence level, showed no statistically significant differences between results obtained by both methods and the reference method. The urethane-acrylate μFBA maintained satisfactory physical and chemical properties, and represents an improvement over conventional flow-batch analyzer.

Folding of a Salivary Intrinsically Disordered Protein upon Binding to Tannins

We used ion mobility spectrometry to explore conformational adaptability of intrinsically disordered proteins bound to their targets in complex mixtures. We investigated the interactions between a human salivary proline-rich protein IB5 and a model of wine and tea tannin: epigallocatechin gallate (EgCG). Collisional cross sections of naked IB5 and IB5 complexed with N = 1-15 tannins were recorded. The data demonstrate that IB5 undergoes an unfolded to folded structural transition upon binding with EgCG.

Immunological effects of tannins through dendritic cell

Ellagitannins widely distributed in medicinal plants have been demonstrated to exhibit diverse biological activities including host-mediated antitumor and immunomodulatory anti-leishmanial effects, which are associated with macrophage activation. In the present study, we examined the immunological effect of oenothein B (1), a macrocyclic ellagitannin dimer with potent antioxidative and antimicrobial activities, on a human dendritic cell (DC) which is one of the important antigen presenting cells. The effect of 1 on DCs was assessed by flow-cytometric analysis and morphological observation using a microscopy comparing with those of (-)-epigallocatechin gallate (EGCG, a green tea tannin). The production of cytokines in LPS stimulated DCs was also analyzed using the ELISA. EGCG and 1 induced the apoptosis of DCs and showed a significant down-regulation for the expression of cell surface molecules, CD1a and CD83, suggesting the inhibition against the maturation of DCs. Oenothein B also suppressed remarkably the production of inflammatory cytokines such as IL-1β and IL-6 in dose-dependent manner. These data may partly be able to explain the traditional use of tannin-containing medicinal plants for treatment of a variety of inflammatory diseases.

Effects of green tea tannin on cisplatin-induced nephropathy in LLC-PK1 cells and rats.

A study was conducted to clarify whether green tea tannin ameliorated cisplatin-induced renal injury in terms of lactate dehydrogenase and malondialdehyde leakage from a renal epithelial cell line, swine-derived LLC-PK1 cells in culture. Green tea tannin was shown to suppress the cytotoxicity of cisplatin, the suppressive effect increasing with the dose of green tea tannin. The effect of cisplatin was then investigated in rats given green tea tannin for 40 days before cisplatin administration and in control rats given no green tea tannin. In control rats, blood, urinary and renal parameters and the activities of antioxidative enzymes in renal tissue deviated from the normal range, indicating dysfunction of the kidneys. In contrast, rats given green tea tannin showed decreased blood levels of urea nitrogen and creatinine, and decreased urinary levels of protein and glucose, reflecting less damage to the kidney. In this group, the activity of catalase in the renal tissue was increased, while the level of malondialdehyde was decreased, suggesting the involvement of radicals in the normalizing of kidney function. Based on the evidence available it appeared that green tea tannin eliminated oxidative stress and was beneficial to renal function.