Journal of Tea Science

A Review on the Technique of Tea Decaffeination

XU Yong-quan, YIN Jun-feng, YUAN Hai-bo, CHEN Jian-xin, WANG Fang

Journal of Tea Science. 2008, 28(1): 1-8. doi:10.13305/j.cnki.jts.2008.01.001

Abstract ( 563 )

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It is reported that tea has many medical functions. However, consumers prefer decaffeinated tea and tea products due to caffeine’s negative disadvantageous. Decaffeination is realized by different methods, including the traditional methods such as water decaffeination, solvent extraction, adsorption separating and supercritical carbon dioxide extraction. The recent developmental microbial and enzymatic degradation and breeding low caffeine tea varieties are also developed for removal of caffeine. The investigation on tea decaffeination was reviewed, and the feasibility was discussed in this paper. The techniques of water decaffeination combined with adsorption separating, microbial and enzymatic degradation as well as low caffeine tea breeding were regarded as the main developmental direction of tea decaffeination by the authors.

Study on the Optimum Machine-plucking Period for High Quality Tea

LUO Yao-ping, TANG Meng, CAI Wei-zhi, WEN Dong-hua, WEN Zheng-jun

Journal of Tea Science. 2008, 28(1): 9-13. doi:10.13305/j.cnki.jts.2008.01.007

Abstract ( 386 )

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On the basis of requirements for producing high quality tea, the seasonal variation of mechanical compositions of machine-plucked tea shoots under three plucking period was investigated when the following three criterions for tea shoots was pre-set up in one bud with one leaf and one bud with two leaves, and two-leaf banjhi. Results showed that high quality tea could be produced when the tea shoots were plucked in the period that 75.0%~84.9% shoots were met the one bud and tow leaves stage, and therefore this period can be defined as the optimum machine-plucking time. It was also showed that if machine-plucking is performed based on the above-defined criterion, the interval of machine-plucking in spring would be around 20 days, if an optimum period of machine-plucking is defined on the basis of the formation of a fish-leaf, it could be 15 days after the formation of fish-leaf in spring and 12 days in autumn. The average maturing time of a tea-leaf is 5.4 days in spring and 4.2 days in autumn in Hangzhou. Thus, a suitable regulation of machine-plucking period, will obtain the required plucked tea shoots for the manufacture of high quality tea.

Studies on the Spatial Variability and Influencing Factors of Trace Elements in Sichuan Mengshan Montanic Tea Plantation Soils

WANG Yong-dong, LIAO Gui-tang, LI Ting-xuan, ZHANG Xi-zhou, HUANG Ping

Journal of Tea Science. 2008, 28(1): 14-21. doi:10.13305/j.cnki.jts.2008.01.008

Abstract ( 336 )

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The subtropical hill region is the main area where the tea plantations are distributed in Chian, Trace elements are very important to tea quality, Study on the spatial variability of trace elements in tea plantation soils is the foundation of precision agriculture. With the original data as basis, the spatial variability of trace elements of montanic tea plantation soil in Mengshan is studied with the aid of principal component analysis and geostatistics model. The result showed: (1) The spatial variability of four trace elements(Fe, Mn, Zn, Cu) in tea plantation soils are similar. All of the theoretical model of trace elements are exponential model, the range of spatial correlation is 206~1 860 m. The spatial correlation of Fe, Mn, Zn belong to medium levels [C₀/(C₀+C): 25.1%~49.6％], the spatial variability between Mn and Cu similar anisotropic characteristic in NE111º, Fe and Zn trends to isotropy. (2) Principal component of comprehensive cartography describe the distribution rule of trace elements in general. Maps of Kriged estimates with principal component showed that the characters of trace elements distributed in a belt shape across the Mengshan mountain, which are in accordance with the result of geostatistic analysis. (3)The mainly influencing factors of tea plantation soil in Mengshan are soil condition and slope.

Effects of Spreading Environment on Tea Polyphenols and Catechin Components in Tea fresh Leaves of High Quality Green Tea

YIN Jun-feng, MIN Hang, XU Yong-quan, YUAN Hai-bo, WEI Kun-kun

Journal of Tea Science. 2008, 28(1): 22-27. doi:10.13305/j.cnki.jts.2008.01.002

Abstract ( 452 )

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Using one bud or one leaf and one bud as material, fresh tea leaves were spread continuously (78%~61%) and spread under different environment conditions, then fixed with liquid nitrogen and freeze-dried, respectively. The effects of spread process and spread environments on the change of tea polyphenols and catechin components were investigated. The results showed that the contents of tea polyphenols and total catechins decreased at beginning and then increased during spreading, total esters type catechins decreased gradually, epigallocatechin gallate (EGCG), gallocatechin gallate (GCG) and epicatechin gallate (ECG) decreased in amount during spreading, whilst epicatechin (EC) and epigallocatechin(EGC) increased, but gallocatechin (GC) could not be checked out in fresh tea leaves and spread tea leaves. With the precondition of that the moisture of spread leaves was controlled at 70%, there was obvious effect of environment temperature and humidity on the change of chemical components during spreading. Contents of tea polyphenols and total catechins decreased in low relative humidity (60%), but increased in high relative humidity (90%). The effects of middle relative humidity (75%) on tea polyphenols and total catechins was correlative with environment temperature.

Monitoring and Evaluation of the Noise from the Working Location with Tea Refinement Processing Equipments and the Factory Boundary

YU Guo-feng, JIN Xin-yi, ZHAO Ai-feng, ZHANG Yuan, LI Shun-kai

Journal of Tea Science. 2008, 28(1): 28-32. doi:10.13305/j.cnki.jts.2008.01.004

Abstract ( 426 )

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By monitoring the noise from working location with tea refinement processing equipments and the factory boundary, the difference was compared. Results showed that, the qualified percentage on the noise from working operations and the factory boundary of the new style tea refinement processing workshop is 100% in the daytime and at night. The qualified percentage on the noise from working operations of the old style tea refinement processing workshop is 33.3%, and the noise from the factory boundary in the daytime is 81.25%, and that at night is 62.5%.

Research on the Correlative Factors of Sensory Quality of High-quality Green Tea

WANG Tong-he, HU Min, ZHANG Jiu-qian, LI Hong

Journal of Tea Science. 2008, 28(1): 33-38. doi:10.13305/j.cnki.jts.2008.01.005

Abstract ( 435 )

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The factors of tea sensory evaluation by biological statistical software SAS9.0 were conducted according to the results of sensory evaluation from Tea Culture Festival in Xinyang city from 2004 to 2007. Results showed that the correlation between liquor color and aroma, taste, infusion was significant, but the correlation between appearance and the other factors was not significant. It was showed that the taste﹥aroma﹥liquor color﹥infusion﹥appearance in comparing with total quality score. The score proportion of color 23, aroma 23, taste 24, appearance 30 was rather reasonable. The correlative equation of each factor and total quality score was established by the method of stepwise regression with the DPS data processing software as follows: Y=25.8852+0.731X₁+0.702X₂+1.02X₃+1.2204X₄+1.03X₅

Investigation on the Function of Monomers in Fuzhuan Tea by High-Throughput Screening

FU Dong-he, LIU Zhong-hua, HUANG Jian-an, CHEN Jin-hua, CHEN Hui-heng

Journal of Tea Science. 2008, 28(1): 39-42. doi:10.13305/j.cnki.jts.2008.01.006

Abstract ( 430 )

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Six compounds separated from Fuzhuan Tea were tested by High-Throughput Screening of model FXR, LXR, PPARδ, PPARγ and 3T3-L1 related to the lipid-depressing and anti-obesity. Results showed that all monomers were active to the models selected. To the active model FXR, gallic acid and ECG were active on the concentration of 50 µg/ml. The activating value of GA and ECG was 1.766 and 3.220 respectively. EGCG was very active on the concentration of 10 µg/ml and 50 µg/ml. The active value reached 6.0 when the concentration was 50 µg/ml. To PPARδ, the three compounds were active when the concentration was 50 µg/ml. The activating value of GC to PPARγ model was 1.619. The activating value of 3- methoxy- 4,5-dihydroxy-benzoic acid in PPARγ model was 1.734. The restraining value of 3,4-dihydroxy-benzoic acid in FXR model was 3.641, while that of CDCA(CK) was 6.435. All the results showed that all the compounds were functional ones.

Distribution of Catechins, Purine Alkaloids and Free Amino Acids in Tea Seedlings

CHEN Lin, WAN Xiao-chun, ZHANG Zheng-zhu, CHEN Qi

Journal of Tea Science. 2008, 28(1): 43-49. doi:10.13305/j.cnki.jts.2008.01.009

Abstract ( 491 )

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：Catechins, purine alkaloids and free amino acids in various parts of tea seedlings (Camellia sinensis cv. Fuyun 6) with four or five leaves were analyzed by HPLC-PDAD and amino acid analyzer. The results showed that catechins and purine alkaloids mainly existed in the leaves and tender stems, and less in the parts below cotyledons. There were higher (–)-epigallocatechin gallate and L-theanine contents in the tender leaves, which decreased as they grew up. L-theanine was especially abundant in the roots of tea seedlings, the same to its precursors, glutamic acid and alanine. L-theanine was largely formed in radicles during germination of tea seeds, and reached 13.429 mg/g of fresh weight when purplish red colored stems of tea seedlings came out. Thus, it would be a promising way to obtain natural L-theanine from the tender roots of tea seedlings and its clones.

Preliminary Study on Gene Expression Differences between Normal Leaves and Albino Leaves of Anji Baicha (Camellia sinensis cv. Baiye1)

WANG Xin-chao, ZHAO Li-ping, YAO Ming-zhe, CHEN Liang, YANG Ya-jun

Journal of Tea Science. 2008, 28(1): 50-55. doi:10.13305/j.cnki.jts.2008.01.010

Abstract ( 498 )

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Differences of gene expression between normal and albino leaves of tea plant (Camellia sinensis cv. Baiye1) were studied by mRNA differential display reverse transcription-PCR (DDRT-PCR). Fifty-eight differentially expressed cDNA fragments were obtained from normal and albino leaves. Twelve of which were confirmed by the analysis of RT-PCR. Among them, 5 fragments were specially expressed in normal leaves, 4 fragments were specially expressed in albino leaves, 1 fragment was up-regulated in normal leaves, and 2 fragments were up-regulated in albino leaves. Through BLASTX analysis with GenBank, 5 cDNA fragments showed high homologous to five known genes, namely soul heme-binding family protein of Arabidopsis thaliana, methionine synthase of Beta vulgaris, gag-pol polyprotein-related in Medicago truncatula, human glyceraldehyde-3-phosphate dehydrogenase pseudogene and ACC synthase of rose, respectively. The other 7 might be novel genes, they showed poor homologous to all proteins in the database.

Effects of Cadmium Stress on Growth of Tea Plant and Physiological Index in Leaves of Mengshan Tea

XIA Jian-guo, LAN Hai-xia

Journal of Tea Science. 2008, 28(1): 56-61. doi:10.13305/j.cnki.jts.2008.01.011

Abstract ( 305 )

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Effects of different cadmium concentrations on growth of tea plant and physiological index in leaves of Mengshan tea were studied with the tea cultured in pots. Results showed that, low concentration of cadmium has no obvious adverse effect on the tea plant. When the cadmium concentration reached 60 mg/kg,the tea plant harmed to die; The chlorophyⅡ(ChⅠ) content of most spring tea supplemented with Cd was higher than CK and the increasing trend was raised firstly and inhibited later. The chlorophyⅡ content of summer tea supplemented with Cd was significantly decreased with increase of cadmium concentration, and the chlorophyⅡ content showed a negative relationship with the cadmium concentration, and the coefficient of correlation was -0.997**. The malondialdehyde (MDA) content in spring and summer tea was significantly enhanced with the increase of cadmium concentration. The coefficient of correlation were 0.970**,0.994**（P<0.01）respectively. The free proline of spring tea was significantly enhanced wiyh the increase of Cd concentration, the coefficient of correlation was 0.829*（P<0.05）, the free proline in summer tea was significantly enhanced, and the coefficient of correlation was 0.980**（P<0.01）,and the content of free praline in summer tea was higher than that in spring tea. The soluble sugar content in spring tea supplemented with Cd was higher than CK and the increasing trend raised firstly and then inhibited, the coefficient of correlation was -0.342;The soluble sugar content of summer tea supplemented with Cd was significantly decreased and the coefficient of correlation was -0.909*（P<0.05）.

The Effect of Different Extracts of Fuzhuan Tea on the Activities of Digesting Enzyme

FU Dong-he, LIU Zhong-hua, HUANG Jian-an, CHEN Hui-heng

Journal of Tea Science. 2008, 28(1): 62-66. doi:10.13305/j.cnki.jts.2008.01.003

Abstract ( 327 )

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Fuzhuan Tea was extracted by chloroform, ethyl acetate, 1-butanol in turn. The effect of Fuzhuan Tea on the activities of metabolize enzyme was investigated. The results showed that different fractions of Fuzhuan Tea had different effects on pancreatic lipase activity. The sample extracted by chloroform could restrain pancreatic lipase a little and the relative activity was 0.82. The water extracts, the sample extracted by ethyl acetate and 1-butanol showed obvious activation, that of the sample extracted by 1-butanol was the most active. The multiple was 2.54. All fractions of Fuzhuan Tea were active to α-amylase, among them, the sample extracted by ethyl acetate was the most active. The relative activiy was 4.09. The water extracts was the second one and its relative activity was 2.99. That of the layer of water sample was not obvious. The sample extracted by chloroform could restrain α-amylase a little and the relative activity was 0.88. The samples separated from the sample extracted by ethyl acetate and the sample extracted by 1-butanol were active to α-amylase and pancreatic lipase respectively.

Protective Effect of Tea Polysaccharides on Carbon Tetrachloride Induced Liver Injury in Mice

FANG Wei, CHEN Yan, SUN Yu-jun

Journal of Tea Science. 2008, 28(1): 67-71. doi:10.13305/j.cnki.jts.2008.01.012

Abstract ( 311 )

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A polysaccharide named TPS-II was isolated from the water extraction of Liu’an Roasted Green Tea and purified by chromatography. The homogeneity of TPS-II was identified, its protective effect on carbon tetrachloride induced liver injury in mice was investigated. Results indicated that the molecular weight of TPS-II is about 1.01×10⁵, whose total content of saccharide and protein were 85.30% and 2.80% respectively, and its protective effect against CCl₄ induced acute liver injury is significant.

Investigation on the Tea Book “Jian Cha Jue”

LIU Xin-qiu, FENG Wei-ying, GU Wen, ZHU Zi-zhen, LI Xing-hui

Journal of Tea Science. 2008, 28(1): 72-76. doi:10.13305/j.cnki.jts.2008.01.013

Abstract ( 300 )

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The tea book “Jian Cha Jue” was written by Ye Jun in Qing Dynasty. It was lost in China. Now, there are Baoli and Mingzhi two editions in only a few Japanese libraries. The earliest edition of Baoli was not written by Ye Jun, but supplemented by the Japanese monk Jiao Zhong. The edition of Mingzhi was prefaced by the Chinese Wang Zhiben who was touring in Japan, and emendated by the Japanese Noboru Oda. They deleted the content which Jiao Zhong supplied when reprinted this tea book, but appended seven issues about tea which from Tu Long “Kao Pan Yu Shi”. Because of these, these two editions of “Jian Cha Jue” in Japan are jumbled. According to these confusions, the paper is on the purpose to resolve these problems.

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