Journal of Tea Science

Effects of Tea Polysaccharide on the Texture Characteristics of Amylose and Amylopectin

LIANG Qin, GUO Li, DU Xian-feng

Journal of Tea Science. 2011, 31(6): 473-478. doi:10.13305/j.cnki.jts.2011.06.001

Abstract ( 551 )

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Compatibility between the two kinds of polymer: amylose and amylopectin has a derect relation with the texture of starchy foods, and the texture will directly influence the processability, morphological structure, storability and edible characteristic of the starchy foods. This article studies the texture characteristics of mixture of tea polysaccharide, amylose and amylopectin at different mixing ratios, the result shows that the quantity of tea polysaccharide have a significant effect on the firmness, consistence, cohesiveness and index of viscosity of amylose, amylopectin and their mixtures.

Season Features of Mineral Elements and Dissolved Rates in Tea of Mengshan

ZHAO Ying, ZHANG Li

Journal of Tea Science. 2011, 31(6): 479-484. doi:10.13305/j.cnki.jts.2011.06.011

Abstract ( 551 )

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The contents of trace elements Ca, Mg, Fe, Mn, Cu and Zn in tea leaves of Mengshan which plucked in different seasons were determined by flame atomic absorption spectrometry (FAAS). The concentration and dissolved rates of six trace elements in their influsiong were calculated. The correlations of trace elements were analyzed using SPSS18.0 analysis software. The result showed that there were abundant trace elements in tea leaves of Mengshan, the contents order is Ca>Mg>Fe>Mn>Zn>Cu. There were positive correlation between Fe and Mn, Ca and Zn. On the contrary, Ca has a negative correlation with Zn. The seasonal dynamics of these elements had obvious regularity in tea leaves. The dissolved rates of various elements were correlated to the form of elements in tea, however, there is no significant relationship between dissolved rates and the plucking seasons.

Multi-walled Carbon Nanotubes-Ionic Liquid Modified Screen-printed Carbon Electrodes for the Determination of Trace Lead in Tea

XU Xu-ming, DOU Wen-chao, ZHAO Guang-ying

Journal of Tea Science. 2011, 31(6): 485-492. doi:10.13305/j.cnki.jts.2011.06.002

Abstract ( 503 )

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A new, high sensitivity and selectivity electrochemical sensor for determination of trace lead in tea by differential pulse stripping voltammetry was investigated. For modification of the screen-printed carbon electrode, 1-butyl-3-methylimidazolium hexafluorophosphate was applied as a super conductive binder and multi-walled carbon nanotubes were used after being functionalized. They improved the conductivity and signal transduction of electrode surface. In pH4.5 NaAc-HAc buffer containing 0.006mol/L I^¯, Pb²⁺ adsorbed onto the surface of MWCNTs-IL film coated SPCE at the deposition potential of –1.1V. During the positive potential sweep, lead was oxidized, and a good stripping peak appeared at –0.30V. Low concentration of I^¯ significantly enhanced the stripping peak current of lead. The liner relationship between stripping peak value and concentration of Pb²⁺ was in the range of 2~600μg/L with the R value of 0.99926 and detection limit of 0.63μg/L. No significant difference existed after the detection results were compared with ICP-MS method using t test. The high sensitivity and stability of this method demonstrated the application for a simple and economical determination of trace lead in tea.

Variation of Catechins and Purine Alkaloids Fingerprints during the Formation of Fresh Scent-Flavor Oolong Tea

CHEN Lin, CHEN Jian, ZHANG Ying-gen, WU Ling-sheng, WANG Zhen-kang, YANG Wei, YOU Zhi-ming

Journal of Tea Science. 2011, 31(6): 493-503. doi:10.13305/j.cnki.jts.2011.06.003

Abstract ( 463 )

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The spring shoots of Tieguanyin, Huangdan, Jinguanyin, Huangguanyin (Camellia sinensis) was respectively used as materials for the test, and catechins and purine alkaloids of the samples prepared during the period of shoot growth and the process of fresh scent-flavor Oolong tea were determined by high-performance liquid chromatography. The results showed that the stability, precision and reproducibility of the method were qualified for requirements to build catechins and purine alkaloids fingerprints of tea samples. When dealt with ChemPattern 2.0 Professional Version, a kind of fingerprint data processing software, the consistent pattern recognition results could be obtained by similarity analysis, cluster analysis and principal component analysis. The fingerprints of various tea samples were quite different during the period of shoot growth, and could be distinguished from the WIP of fresh scent-flavor Oolong tea. Every tea sample of the WIP of fresh scent-flavor Oolong tea could be well identified by cluster analysis (Euclidean-Nearest Neighbor), especially for principal component analysis (data pretreated with Log Transformation). The change in the content of (-)-epigallocatechin (EGC) was the most obvious during the period of shoot growth in each tea sample, which was followed by (-)-epigallocatechin gallate (EGCG) and caffeine. While the change in the content of (-)-epigallocatechin gallate (EGCG) was more obvious during the process of fresh scent-flavor Oolong tea, which was followed by EGC. The contents and compositions of catechins and purine alkaloids changed more significantly during the period of shoot growth than those in the process of fen-flavor Oolong tea.

Study on Physiological Characteristic of Tea Plant Inoculated by VA Mycorrhiza

LI Yuan-hua, ZHENG Fang, NI De-jiang, YANG Jiang-fan, SHI Yu-tao

Journal of Tea Science. 2011, 31(6): 504-512. doi:10.13305/j.cnki.jts.2011.06.012

Abstract ( 447 )

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The physiological characteristic of tea plant inoculated by VA mycorrhiza was studied. Results showed that 50d after inoculation, the chlorophyll content in tea leaves inoculated by VA mycorrhiza was higher than that uninoculated by VA mycorrhiza. Results also indicated when the photosynthetical available radiation was in the range of 0~1200μmol/m²·s, the net photosynthesis rate, the stomata conductance and the transpiration rate of the tea plant inoculated by VA mycorrhiza were all higher than those of the control, the water use efficiency (WUE) increased rapidly in earlier stage, then decreased gradually after reaching the peak, the degrees of saturation of leaves decreased gradually. After the tea plant inoculated by VA mycorrhiza, MDA content of tea leaves decreased while the hydroxyproline content decreased first and increased later with the increase of infection rate. The inoculation of VA mycorrhiza can improve the activities of protective enzymes of tea plant. During the resied of 90d after inoculation, the activity of POD reached the peak, the activity of SOD increased slightly first and then decreased smoothly. CAT activity of tea plant treated by VA mycorrhiza was always higher than that of the control.

NO₃^--N Concentration and Net Nitrification Rate in Tea Soils

HAN Wen-yan, XU Jian-ming

Journal of Tea Science. 2011, 31(6): 513-520. doi:10.13305/j.cnki.jts.2011.06.013

Abstract ( 419 )

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An investigation of NO₃^--N concentration and net nitrification rate in 130 tea soil samples was conducted. The net nitrification rate was measured by laboratory incubation method. The results showed that the NO₃^--N concentration ranged from 0 to 286.8mg/kg with a mean of 41.7mg/kg. Among all the samples, 40.8% of the soils were less than 20mg/kg in NO₃^--N concentration. Soil NO₃^--N concentration had a significant relationship with N application rate, but no obvious relation with soil net nitrification rate. A quadratic equation Y=738.0-289.9X+28.8X²（r²=0.2033, P<0.001） was established between NO₃^--N concentration (Y) and pH (X). Soil net nitrification rate ranged from -6.08 to 6.54 with a mean of 1.62mg/kg·d, and coefficient of variation (CV) was as high as 119%. 10% of the soil samples were below 0 in net nitrification rate, indicating net immobilization of nitrate happened in these soils. Net nitrification rate was positively and significantly related with N application rate. And an inverse function Y=10.14-33.96/X（r²=0.253, P<0.001）was found between net nitrification rate (Y) and soil pH (X). Why nitrate accumulated in tea soils and relationship between nitrification and pH was discussed.

Study and Identification of Cold Resistance of Camellia Sinensis by Chlorophyll Fluorescence Method

PANG Lei, ZHOU Xiao-sheng, LI Ye-yun, JIANG Chang-jun

Journal of Tea Science. 2011, 31(6): 521-524. doi:10.13305/j.cnki.jts.2011.06.014

Abstract ( 469 )

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Application of chlorophyll fluorescence technique has shown a favorable prospect in the research field for plant resistance. In the present research, referring to the measurement results by electrolyte conductivity method, appropriate chlorophyll fluorescence parameters were studied for the determination of cold resistance of tea plants. The results showed that the cold resistance of different tea cultivars measured by chlorophyll fluorescence parameter Fv/Fm with logistic equation was the same as which were obtained by electrolyte conductivity method: cv.Shuchazao> cv.Wancha91> cv.Pingyangtezao. However, the determination conclusions by Fv/Fo, Fm and Fo were not correspond to the result acquired by electrolyte conductivity method. For the determination of plant resistance, we concluded that chlorophyll fluorescence method is more convenient and less interfered than the traditional electrolyte conductivity method. Therefore, it was treated as a new method to identify the cold resistance of tea plants.

Effect of Tea Polyphenols Concentration on the Stability of Green Tea Infusion

XU Yong-quan, LIU Ping, CHEN Gen-sheng, CHEN Jian-xin, YUAN Hai-bo, YIN Jun-feng

Journal of Tea Science. 2011, 31(6): 525-531. doi:10.13305/j.cnki.jts.2011.06.004

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The chemical components and sensory quality of green tea infusion with different tea polyphenols concentrations were compared and investigated during the sterilization and storage. The results showed that, the stability of green tea infusions with different tea polyphenols concentrations was different. During the sterilization and storage, the color of green tea infusion darkened and turned red, contents of tea polyphenols and catechins decreased markedly, contents of flavones and gallic acid increased evidently, contents of caffeine and amino acids reduced slightly, sensory quality reduced obviously and ripe taste enhanced. With the increasing of tea polyphenols concentration, the change of chemical components and sensory quality strengthen, the degree of change under the high-temperature (37℃) storage was much larger than that under the low-temperature (4℃) storage. The stability of green tea infusion was relatively higher when tea polyphenols concentration was ranged from 400mg/L to 600mg/L.

Study on the EGCG from Tea on the Blood Anticoagulation Effect of Mice

WANG Xian-bo, CHENG Hao, ZHAO Yun, HUANG Hai-tao

Journal of Tea Science. 2011, 31(6): 532-536. doi:10.13305/j.cnki.jts.2011.06.009

Abstract ( 567 )

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The effect of EGCG on blood anticoagulation of mice was evaluated in this investigation. Results showed that EGCG with doses of 0.25g/(kg·d), 0.5g/(kg·d) and 1.0g/(kg·d)could significantly prolong bleeding time of mice tail and activated the partial thromboplastin time compared with control group, effectively depress fibrinogen level, while EGCG nearly has no impact on mice prothrombin time. EGCG with doses of 0.5g/(kg·d) and 1.0g/(kg·d) could effectively prolong coagulation time compared with control group. It is calculated that EGCG could inhibit the intrinsic coagulation pathway and prolong the blood coagulation time. EGCG showed obvious blood anticoagulation effect.

Selection of Clarifiers of Fermented Tea Wine

QIU Xin-ping, LI Li-xiang, NI Yuan, XU Rui-rui, JIANG Qi-zhong

Journal of Tea Science. 2011, 31(6): 537-545. doi:10.13305/j.cnki.jts.2011.06.010

Abstract ( 552 )

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Six clarifiers including bentonite, gelatine, chitosan, casein, diatomite and PVPP were applied separately in the clarifying treatment of fermented tea wine and their effects were evaluated through the determination of the light transmittance, absorbency value, alcoholicity, residual sugar, polyphenol compound and acidity of the fermented tea wine. Results indicated that the optimum addition quantity of bentonite, gelatine, chitosan, casein and diatomite were 0.6g/L, 0.2g/L, 1.0g/L, 0.2g/L and 0.4g/L, and PVPP was not suitable as clarifier of tea wine. And chitosan was the best clarifier for the tea wine.

Research on The Status of Chinese Tea Consumption and Factors of Tea Consumer’s Behavior

GUAN Xi, YANG Jiang-fan, XIE Xiang-ying, LIN Li-qiong

Journal of Tea Science. 2011, 31(6): 546-551. doi:10.13305/j.cnki.jts.2011.06.006

Abstract ( 847 )

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By using logistic models and data from China Health and Nutrition Survey, the paper analyze the status of tea consumption in China and its influencing factors. The results showed that the consumer's age, gender, urban and rural areas, education, income and region affect the drinking behavior of consumers, the factor of age, education level and income showed significant positive effect on the consumer’s drinking, while male and urban consumers have higher possibility of drinking tea comparing to the female and rural consumer, and consumers in central-eastern region have lower possibility of drinking tea comparing to the western consumers. Based on the conclusion, the corresponding policy recommendations were put forward.

Comparison of Tea Industry Policy Orientation between China and Japan and Their Quotable Experiences for Korea Drawing on

SHIN So-hee, LIANG Yue-rong

Journal of Tea Science. 2011, 31(6): 552-560. doi:10.13305/j.cnki.jts.2011.06.010

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Policy orientation in tea industry between China and Japan was compared and their quotable experiences for Korea to draw on were discussed. The universality in tea industry policy orientation of China and Japan was to optimize tea product structure aiming at lifting top grade teas, to promote organization of tea farmers through mutual aid association, to increase regional competitiveness by intensive management and individuation of product quality, to improve economic performance through comprehensive utilization of tea resources. The differences between these two countries are as follows: China emphasize the production efficiency of top grade teas, bring about the scale economy which takes the producers as the center and maximizing the utilization of regional tea resources to realize differentiation strategy of products and marketing; Japan focuse on the individuality of top grade teas, the marketing strategy takes the producers as the center, the diversification of the regional tea industry and the economical and ecological benefits during utilization of tea resources. It is considered that Korea should draw on China and Japan’s experiences in policy orientation to promote its tea industry.

Study on Scientific Input-output Efficiency of Tea Research Institute in China during the Year of 2006~2010

YANG Zhen-wei, YANG Ya-jun

Journal of Tea Science. 2011, 31(6): 561-566. doi:10.13305/j.cnki.jts.2011.06.007

Abstract ( 481 )

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The scientific input-output efficiency of ten Tea Research Institutes at or above provincial level in China was investigated by using DEA method during the year of 2006~2010. The result showed that institutes’ input & output efficiency keep well in total, but not 100% is efficient. Nine institutes were effective, and their scale and resources allocation level was in good situation. One institute was PE invalid and in scale decrease stage, it needs to strengthened scientific research management and improved resource allocative efficiency, to increase output and make DEA efficient. The correlation between input item and output item was investigated. The results showed that all outputs items correlate positively with the input items of fund and staff, while not positively with per capita fund.

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