[en] In the present study, twenty four commercial tea samples were assayed to determine their free radical scavenging activity and polyphenolic contents based on the brewing/infusing period. Tea samples were infused/brewed in 200 mL boiled water at 120 degree C for 1, 2 and 5 min, respectively. The radical scavenging activities of tea infusion/brewing were measured using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay method. The results were ranged from 67.81-90.51% for black tea bags, 90.37-94.51% for green tea bags, 24.66-92.25% for black tea powder, 16.08-93.06% for green tea powder and 32.90- 45.54% for Camomile herbal infusion. The results showed that 1 or 2 min black tea bags infusion exhibited highest radical scavenging activity than 5 min infusion. Antioxidant activities of tea powders were variable with the amount of tea powder. It was observed that antioxidant activity increased with increasing boiling time for smaller amount of sample. In contrary, shorter boiling time was better for larger amount of sample. The polyphenol contents of tea infusion were determined and the results were expressed as milligram quercetin equivalent/200 mL of tea infusion. The polyphenol content was increased with increased brewing period. In contrary, brewing for longer time rendered extract less antiradical activity. This study suggests that infusing tea bag for 1 or 2 min is sufficient for getting infusion with maximum radical scavenging activity and in case of tea powder, shorter boiling time is better for larger amount of powder or small amount of powder should be boiled for minimum 5 min for rendering extract with maximum radical scavenging activity. (author)

[en] In the present study, feasibility of producing high quality of tea polyphenols, the anine and caffeine from the extract of summer green tea by column chromatography was investigated. Crude extract of summer green tea obtained by hot water extraction was passed through columns of polyamide and NKA-II macroporous resin respectively, resulting in tea polyphenols-enriched fraction (96.27 +- 1.78%), the anine-enriched fraction (99.02 +- 0.43%) and caffeine-enriched fraction (99.25 +- 0.36%). The recovery rates for tea polyphenols, the anine and caffeine were 72.42 +- 1.41%, 66.12 +- 1.66% and 62.07 +- 2.17%, respectively. The separation procedure allowed the production of such products by decreasing impurities and avoiding the use of poisonous organic solvent. The results suggested that it was possible to produce high-quality products of rich-in tea polyphenols, the anine and caffeine by a simple way. From industrial point of view, this novel method has many merits such as high efficiency of separation, low consumption of energy and environment-friendly procedure. (author)

[en] Experiments on the removal and recovery of U(VI) from aqueous solution by tea waste were conducted. The adsorbent was characterized by scanning electron microscope and energy dispersive spectrometer before and after the adsorption treatment. The removal of U(VI) amounts to 86.80 % at optimum pH 6. The adsorption process reaches its equilibrium in 12 h at 308 K, and the kinetic characteristic can be described by the pseudo-second-order kinetic equation. The amount of adsorption increases from 22.92 to 142.21 mg g^-1 with the decrease of tea waste dosage from 100 to 10 mg for solution with an initial uranium concentration of 50 mg L^-1. Desorption for the four strippants is higher than 80 %. The equilibrium data are more agreeable with Freundlich isotherm than Langmuir isotherm. (author)

[en] In some tea tree planting areas within 300 km from the TEPCO's Fukushima Daiichi Nuclear Power Plant (FNPP), it was found that newly emerged tea plant leaves for green tea contained two radiocesium species (cesium-134 and cesium-137). In this study, using processed green tea leaves for drinking, extraction ratios of radiocesium under several brew conditions were observed. When 90 deg C water was used, 50-70% of radiocesium was extracted into the water, while 54-60% of radiocesium was extracted with 60 deg C water. A part of radiocesium would be removed from leaves if the leaves were washed with 20 and 60 deg C water before brewing, and the efficiencies were 11 and 32%, respectively. Newly emerged camellia leaves were used to simulate the radiocesium removal ratio from raw tea leaves by washing and boiling; radioactivity concentration was decreased to 60% of the original concentration with washing and 10 min boiling. From these results, it was found that almost half of the radiocesium would not be removed from raw or processed tea leaves. The values obtained in the present study could be used for internal radiation dose estimation from tea leaves. (author)

No abstract available

[en] Analysis of Br, La, Ca, Sc, Cr, Fe, Rb, Sb, Co, Zn, Eu, As, Se, Cs, and Hg, in tea leaves sample has been carried out either as micro trace elements. Analysis were carried out by irradiating the samples for 36 hours followed by two days cooling in TRIGA-MARK reactor, at thermal neutron flux of 10 exp. 11 n/cm2s. Multi Channel Analyzer was use for identifying the energy of gamma ray emitted. The result obtained in term of concentration range were Br 2.82-4.95 ppm; La 0.13-3.84 ppm; Sc 0.10-0.88 ppm; Cr 0.18-1.03 ppm; Ca 0.28-0.94 ppm; Fe 161.33-894.11 ppm Rb 50.42-144.61 ppm; Sb 0.09-0.88 ppm; Co 0.06-0.18 ppm; Zn 11.17-33.50 ppm; Eu 0.01-0.06 ppm; As 0.14-1.50 ppm; Se 3-60 ppb; Cs 0.07-0.38 ppm and Hg 10-80 ppb. (author). 7 refs, 3 figs, 4 tabs

[en] Background: Insecticide toxicity is the problem of every person in under developed countries. It is necessary to counteract its effect by natural and cheap remedies like green tea and vitamin C. In this manner common man can also enjoy blessings of life. The current research was performed to compare the protective function of green tea and vitamin C on experimental cypermethrin provoked nephrotoxicity Method: Forty healthy Balb/C mice purchased from National Institute of Health, Islamabad, Pakistan and divided in to four groups (10 each). Group a was control which received only normal diet. Group B, group C and group D were experimental groups which were given Cypermethrin, Cypermethrin with green tea and Cypermethrin with vitamin C respectively. These groups were also given normal diet. After 1 month blood was drawn by intra-cardiac method to assess renal parameters. Results: One month research showed increase in serum urea to 6.8±.48 m.mol/l (n=3.9±.44) while green tea and vitamin C normalize them to 4.0±.83 m.mol/l and 3.4±.33 m.mol/l respectively. Serum creatinine increased to 42.90±3.28 m.mol/l (n=29.50±3.95) while green tea and vitamin C normalize them to 28.80±4.58 m.mol/l and 22.60±2.06 m.mol/l correspondingly. Conclusion The results showed that green tea and vitamin C neutralized toxicity induced by Cypermethrin in mice and their effect is comparable. (author)

[en] To evaluate the effects of green tea on liver histology of mice on high fat diet. Study Design: Analytical experimental randomized control trial. Place and Duration of Study: Department of Anatomy in collaboration with the Department of Pathology, Army Medical College, Rawalpindi and National Institute of Health, Islamabad. Twelve weeks study. Material and Methods: Sixty adult mice, Balb-c, strain were selected and divided into three groups. The control group was given standard laboratory diet throughout the study. In experimental group A, the study was carried out in two phases. In the first phase, hepatic steatosis was induced by high fat diet containing 4 percent cholesterol powder and 40 percent butter fat for six weeks. In the second phase, experimental group was given normal diet with 1 percent green tea over a period of next six weeks. The experimental group B was given high fat diet containing 4 percent cholesterol powder and 40 percent butter fat with 1 percent green tea over a period of twelve weeks. Ten mice in each group were sacrificed at six weeks and remaining ten were sacrificed at twelve weeks.Results: High fat diet for six weeks produced significant hepatic steatosis, evident on histological analysis. When experimental group A (induction phase) with high fat diet was compared with the (reversal phase) on normal diet and green tea, statistically significant difference (p<0.05) was noted in terms of liver histology. Green tea reverted all parameters in experimental group B, which though reduced never reached the control value and remained somewhat elevated. Conclusion: It is therefore concluded that green tea protects against the development of hepatic steatosis and reduces hepatic injury in mice. (author)

[en] Full text: A solid extract of procyanidins from green tea was studied by ESR, using a Varian E-12 (X-band: ∼9.1 GHz) spectrometer, at room temperature, and liquid N₂ temperature. The spectrum consisted of three unstructured lines, one ∼20 gauss wide, one ∼ 10 gauss wide, and one ∼3 gauss wide. Saturation behaviour of these lines at room and liquid N₂ temperature showed them to be from different radicals. About 50% of the extract is epogallocatechin gallate (EGCG). Using a pure sample of EGCG, it was possible to assign the broadest and strongest 'single' signal to EGCG. It has not been possible yet to assign the other lines to other molecular species

[en] The removal of Co²⁺ in aqueous solution by spent green tealeaves (SGTL) was studied in batch conditions. The bio-sorbent was characterized by the infrared spectroscopy, Boehm's titration and by pHpzc. The optimum pH value was found in the range of 4 to 6. The sorption was fast, obeyed the pseudo second order model, and favored at low temperature. The bio-sorption capacity recorded a rate of 83.52% using 0.25 g of SGTL. The isotherm followed the Langmuir model. The Co²⁺ bio-sorption is exothermic, reversible and favorable and that it was carried out by physic sorption with low activation energy. (author)