Journal of Tea Science

Study on Chemistry and Bioactivities of Tea Polysaccharides

XU Zhong-xi, WANG Kun-bo

Journal of Tea Science. 2004, 24(2): 75-81. doi:10.13305/j.cnki.jts.2004.02.001

Abstract ( 399 )

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The recent researches have found that tea polysaccharide has many bioactivities, such as anti-thrombosis, reducing blood-sugar, blood-lipid and pressure depressing and strengthening the body's immunity. It can be used in curing diabetes and cardiovascular disorder as healthy foods and subsidiary medicine. The methods of extraction and purification, determination of purity and molecular weight, chemical composition, and bioactivities of tea polysaccharide are summarized.

The Development and Tendency on the New Technology Application in Tea Quality Evaluation

ZHOU Yi-bin, WANG Jun

Journal of Tea Science. 2004, 24(2): 82-85. doi:10.13305/j.cnki.jts.2004.02.002

Abstract ( 476 )

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Basically, the quality of tea is evaluated by the tea experts through senses. The sensitivity of human’s sense, however, is liable to be changed by external factors, therefore, it is not easy to make an accurate evaluation through human’s sense. The paper presents the new research development in evaluating tea quality such as the shape of tea, the color of tea infusion, the aroma and taste of tea by instruments, especially the application of the machine vision to the shape of tea and the color of tea infusion, the electronic nose to the tea aroma and the electronic tongue to the taste of tea, it put forwards the tendency of the new technology application to tea quality evaluation.

Genetic Diversity Estimates for Darjeeling Tea Clones Based on Amplified Fragment Length Polymorphism Markers

Rajan Kumar Mishra, Swati Sen-Mandi

Journal of Tea Science. 2004, 24(2): 86-92. doi:10.13305/j.cnki.jts.2004.02.003

Abstract ( 309 )

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Tea plants growing in Darjeeling area, in addition to all other factors described below, are unique due to their typical geographical isolation. DNA fingerprints revealed a high degree of polymorphism in genomes of different clones, and this demonstrated the suitability of using the Amplified Fragment Length Polymorphism (AFLP) method for genome analysis between closely related plants, such as vegetatively propagated (clonal) populations of tea. Cluster analysis exhibited a dendrogram that closely matched with earlier clonal grouping based on morphological characters. The extent of genetic relatedness between the clones was found to be at 70% level. Results also showed that the genetic variation (Hs) was higher among China type. The variation between and within the three types of clonal populations studied (viz. China, Assam and Cambod type) are 63% and 36% respectively.

Genotypic Difference of Nitrogen Efficiency in Tea Plant [Camellia sinensis (L.) O. Kuntze]

WANG Xin-chao, YANG Ya-jun, CHEN Liang, RUAN Jian-yun

Journal of Tea Science. 2004, 24(2): 93-98. doi:10.13305/j.cnki.jts.2004.02.004

Abstract ( 354 )

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Pot experiment with 6 tea plant genotypes was conducted to investigate the genotypic difference in N efficiency at 4 N levels. The results showed that there were significant difference in increased biomass yield, increased new shoots, N uptake efficiency, N physiological utilization efficiency, N economic efficiency and N use efficiency among 6 tea plant genotypes. The difference of N uptake efficiency was the main fact that resulted in the N use efficiency among tea plant genotypes.

Effect of Chemical Insecticides on the Diversity of Arthropods in Tea Garden

WANG Guo-hua, LIANG Yuan-fa, TIAN Yong-hui, WANG Jia-lum, ZHOU Guo-lan

Journal of Tea Science. 2004, 24(2): 99-104. doi:10.13305/j.cnki.jts.2004.02.005

Abstract ( 426 )

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The effect of chemical insecticides on the structure and diversity of arthropods in various tea gardens were investigated. Results showed that the effect of chemical insecticides on the arthropods in tea gardens reflected in the structure and the constitution of species, the diversity index and the distributive evenness of species. The index of population density of dominant insect pest was increased greatly in those tea gardens with higher chemical insecticide expense, especially for tea leaf hopper (Empoasca vitis Gotho). The regulatory effect of natural enemies on major insect pest was increased in those tea gardens with lower expenses of insecticides. Besides, the diversity index and the evenness index were increased at the same time.

Study on the Burning Character of Tea-seed Oil as An Alternative Fuel in Diesel Engine

MA Rong-chao, QIN Wen

Journal of Tea Science. 2004, 24(2): 105-108. doi:10.13305/j.cnki.jts.2004.02.006

Abstract ( 452 )

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Vegetal energy is becoming one of the important energy sources for diesel engine. A test of burning character on S195 diesel engine was carried out using tea-seed oil as the alternative fuel. The results showed that it is feasible to burn mixture oil of tea-seed oil and diesel oil without changing the structure of the engine. When burning the tea-seed oil or mixture fuel in the engine, the exhaust pollution is on decline, but the specific fuel consumption rats and deposit charcoal of combustion chambers and injection nozzles are more than ever. The performance of the engine is rather good when burning the mixture of tea-seed oil and diesel oil in same volume and the angle of pre-oil-supplied is 19^o CA.

Chemical Forms of Lead and Cadmium in Soils from Some Tea Gardens near Highway

ZHANG Ming-kui，HUANG Chang-yong

Journal of Tea Science. 2004, 24(2): 109-114. doi:10.13305/j.cnki.jts.2004.02.007

Abstract ( 338 )

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Three soil profiles and twenty-three surface soil samples, developed from various parent materials, were collected from different tea gardens near highway in Zhejiang province. The total, five chemical fractions (exchangeable, carbonate bound, organic matter-bound, oxides bound and residual forms) and water-solubility of Pb and Cd in the soils were characterized. The results showed that concentrations of total and different chemical fractions of Pb and Cd in the soils varied with locations and soil properties. Increased Pb and Cd concentrations in surface layer of the soil profiles suggested that Pb and Cd accumulation in the soils was related to soil pollution and fertilizer application. The concentrations of organic matter-bound, oxides bound and residual forms of Pb and Cd were mainly controlled by total Pb and Cd in the soils. However, exchangeable and water-soluble Pb and Cd, which had high potential risk, increased with decreasing pH. The results indicate that long-term plantation of tea could cause sol acidification and elevated concentrations of bio-available heavy metals in the soil, and hence aggravated the risk of heavy metals.

Dynamics of Theanine Biosynthesis in Tea Suspension Cells

CHENG Hao, GAO Xiu-qing

Journal of Tea Science. 2004, 24(2): 115-118. doi:10.13305/j.cnki.jts.2004.02.008

Abstract ( 369 )

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The level of theanine biosynthesis of tea cultured cells initiated from different explant material and the dynamics of theanine biosynthesis in tea suspension cell were analyzed. The suitable medium for theanine biosynthesis and the effect of medium renewal were also tested. According to the result, the peak of theanine accumulation was appeared on the 11^th day during a culture cycle. But if the medium was renewed in an interval of 10 days, theanine could be continuously accumulated in the cells until about the 30^th day and reached a high peak of 20% cell dry weight.

Derivation of Theanine and Its Determination by Capillary Electrophoresis

LI Ping, WAN Xiao-chun, LI Jian, ZHANG Zheng-zhu, SHEN Zuo-jun

Journal of Tea Science. 2004, 24(2): 119-123. doi:10.13305/j.cnki.jts.2004.02.009

Abstract ( 405 )

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A novel derivative method for determination of theanine was developed by micellar electrokinetic capillary chromatography (MECC). Samples were derivated with 2,4-dinitrofluorobenzen. The buffer solution used in this method was 0.03mol/L sodium borate solution (pH9.8). Column temperature was 17℃. The separating voltage was 28βkV and detection at 360βnm. Factors of pH value, reaction time, reaction temperature and concentration of buffer were optimized. The products of derivation of theanine can be stable for five days at 4℃ or 25℃. The linearity of this assay was 0.2~5βmmol/L (r²=0.993). The minimal detection limit (S/N=2) was 0.05βmmol/L.

HPLC Quantitation of Theaflavins in Tea Pigments

LI Da-xiang, WAN Xiao-chun, LIU Li-hua, XIA Tao

Journal of Tea Science. 2004, 24(2): 124-128. doi:10.13305/j.cnki.jts.2004.02.010

Abstract ( 422 )

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In this study, theaflavin(TF1), theaflavin monogallate(TF2+TF3) and theaflavin digallate(TF4) in tea pigments are isolated and purified with high speed counter current chromatography combined with Sephadex LH-20 and semi-preparative HPLC. With the purified theaflavin, the standard curves have been set up by HPLC for theaflavins quantitation. The results on the accuracy and recovery determination showed that the coefficient of variation of TF1, TF2+TF3, TF4 and total theaflavins range from 2.6’8.5%, 2.0’3.8%, 2.0’3.9% and 2.2’4.1% respectively. Using HPLC quantitation, the relative error of total theaflavins amounts in the standard theaflavins from Sigma company is 3.4%. The total amounts of theaflavins in tea pigments are 20.5%, in which TF1, TF2+TF3 and TF4 are 6.0%, 9.1% and 5.4% respectively. This method is useful to quantify theaflavins and to control the quality of tea pigments, which could promote the studies on their pharmacological effects.

Selection of Optimum Conditions for Theaflavin Transformation from Tea Polyphenol through Immobilized Enzyme Membrane

TU You-ying, FANG Qing, LIANG Hui-ling, HUANG Hai-tao

Journal of Tea Science. 2004, 24(2): 129-134. doi:10.13305/j.cnki.jts.2004.02.011

Abstract ( 315 )

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Immobilized polyphenol oxidases (IPPO) was applied for the synthesis of theaflavins using tea catechins as substrates. A Response Surface Methodological (RSM) study was conducted using a five-level, five-variable, central composite rotation design (CCRD) to select the optimum catalysis conditions for theaflavin transformation from tea polyphenol through immobilized enzyme membrane. Five important variables were considered, namely, incubation duration, enzyme/substrate ratio (E/S, Activity Units/ml-AU/ml), aeration volume, concentration of tea polyphenols, and the pH value of the reaction system. The highest theaflavins concentration of 0.766βmg/ml was predicted under the conditions as with 49βmin for the incubation duration, 128.7 for E/S ratio, 23.81βml/min ventilation for air volume, 5.95βmg/ml for catechins concentration, and pH 4.3. The measured theaflavins concentration was 0.754±0.017βmg/ml under the same condition, which suggested that the prediction model was practical and the selected conditions were reasonable.

Effect of Dietary Tea Polyphenols on Performances, Lipid Metabolism and Egg Quality of Laying Hens

LOU Hong-xing, LIN Zi, WANG You-ming, LU Fu-zhuang, TANG Jun-feng, YING Jun-feng, YANG Zhong-ming

Journal of Tea Science. 2004, 24(2): 135-140. doi:10.13305/j.cnki.jts.2004.02.012

Abstract ( 440 )

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There were two feeding trials in this research. 225 37-week-old Lohamann laying hens were randomly divided into five treatments for trial one,fed a basal diet supplemented with 0, 0.05, 0.1, 0.2, 0.4 percentage tea polyphenols(TP) for a period of 59 days, respectively.600 51-week-old Lohamann laying hens were randomly divided into four treatments for trial two, fed a basal diet added with 0, 0.025, 0.05, 0.1 percentage TP for a period of 8 weeks, respectively. Dietary effects of TP supplementation on performance, lipid metabolism and egg quality were investigated in laying hens. The results showed that: (1) Egg production and feed conversion efficiency were improved to a certain extent by supplementing TP, but they were not improved with the increasing levels of added TP. (2) The addition of 0.1% TP in diet increased egg yolk VE and VA concentration by 58.99% and 20.96%, respectively. And TP was tended to increase whole egg amino acid levels containing S. The supplementation of 0.025%—0.1% TP in diet of layers at later period decreased broken and soft-shelled egg rates by 31.59%—47.09%. (3) The addition of 0.4% TP in diet decreased total cholesterol (TCH), triglyceride(TG), LDL-C contents of layer serum with 46 week old by 19.65%, 19.99% and 7.69%, respectively, and increased HDL-C by 45.35%. No significant change of 0.025%—0.1% TP supplementation on serum lipid levels was found in layers with 59βw old.

Study on the Stabilizing Mechanism of Konjac Glucomannan in Tea Drink

GONG Jia-shun, LIU Pei-ying, LIU Qin-jin

Journal of Tea Science. 2004, 24(2): 141-146. doi:10.13305/j.cnki.jts.2004.02.013

Abstract ( 357 )

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The stabilizing mechanism of konjac glucomannan in tea drink was studied. By using ethanol precipitation method and the pictures of SEM and TEM revealed that the strong sorption between the konjac glucomannan（KGM） and components or the particles of tea extracts produced hydrogen complexes and, furthermore, the hydrogen complexes could be well dispersed in the system of konjac-tea drink. The X-ray diffraction and differential scanning calorimetry (DSC) indicated that the powder of KGM, tea extracts and konjac-tea solids are amorphous. The experimental results also showed that the molecule weight of KGM in water solution and black tea and oolong tea liquid were 4.83378×10⁵, 3.41182×10⁵, and 3.51307×10⁵, respectively, and the fact of konjac-tea drink had a strong ability of bearing precipitation of electrolyte because of KGM additions was confirmed.

Study on β-glucosidase Gene in Tea [Camellia sinensis (L.) O. kuntze] Leaves by in situ PCR

LI Yuan-hua, JIANG Chang-jun, YU You-ben

Journal of Tea Science. 2004, 24(2): 147-150. doi:10.13305/j.cnki.jts.2004.02.014

Abstract ( 274 )

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