25 September 2005, Volume 25 Issue 3

    

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  Effects of Acidification and Organic Matter Accumulation on Lead Bio-availability in Tea Garden Soils

  ZHANG Ming-kui, FANG Li-ping, ZHANG Lu-qing

  Journal of Tea Science. 2005, 25(3): 159-164. https://doi.org/10.13305/j.cnki.jts.2005.03.001

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  The increased accumulation of lead (Pb) in tea is widely concerned. The study on the factors influencing Pb concentration in tea is necessary for the production of high quality tea. In this study, soils of two tea gardens (Yellowish red soil and Red soil) were collected and incubated by adding acid and organic manure for studying the effects of acidification and organic matter accumulation on Pb bio-availability of tea garden soils. Water-soluble Pb, NH₄OAc extractable Pb and chemical forms of Pb in the incubated soils were characterized. The results showed that soil acidification promoted transformation of other forms of Pb into exchangeable Pb, and thus increased water solubility and bio-availability of Pb in the soils. Accumulation of organic matter could activate Pb in soils with pH>4, whereas accumulation of organic matter decreased Pb bio-availability in lower pH soils (pH<4). The effects of pH and organic matter on Pb bio-availability were more significant in sandy soil than that in clayey soil.
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  Modeling for the Optimization of Fertilization of Tea High Yield

  XIA Jian-guo, LI Jing, GONG Fa-yong, WU De-yong

  Journal of Tea Science. 2005, 25(3): 165-171. https://doi.org/10.13305/j.cnki.jts.2005.03.002

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  The return two times set up juices optimumly trying to adopt“311-B”,a three-factor (N,P,K)substrate cultivation experiment was conducted by using tea. The regression equations of the relationship between N, P, K and the effects on the yield were established. The results indicated that the yield of tea would increase with high nitrogen supply, and P, K had certain effects on it, the order is N>P>K, the interactions of N-P, N-K and P-K to the yield were significant. Considering both the yield and quality of the hot pepper, the combinations of N, R K were optimized as follows: N: 0.406~0.435βg/kg soil, P₂O₅: 0.159~0.170βg/kg soil, K₂O: 0.186~0.198βg/kg soil, and N:P₂O₅:K₂O was 1:0.39:0.46.
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  The Optimization Research on Tissue Culture and Rapid Propagation of Camellia Sinensis

  ZHOU Jian, CHENG Hao, WANG Li-yuan

  Journal of Tea Science. 2005, 25(3): 172-176. https://doi.org/10.13305/j.cnki.jts.2005.03.003

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  The effect of different hormone on proliferation and growth of tea tissue culture seedlings were investigated, and an optimal culture medium of MS + BA 2.0 + NAA 0.1 + GA3 3.0βmg/L was screened out. On this optimal medium, the proliferation rate of tea cultured buds was 2.75 times after 30’s incubation. And more than 20% of those buds could developed to seedlings higher than 5βcm.
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  Molecular Cloning and Sequence Analysis on cDNA of Cystatin Gene from Tea Leaves

  WANG Zhao-xia, LI Ye-yun, JIANG Chang-jun, YU You-ben

  Journal of Tea Science. 2005, 25(3): 177-182. https://doi.org/10.13305/j.cnki.jts.2005.03.004

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  Two degenerate primers were designed according to the conserved region among the known plant cystatins. A cDNA fragment of 204βbp was amplified by RT-PCR (reverse transcription polymerase chain reaction) of total RNA extracted from fresh leaves of Tea plant (Camellia sinensis cv Longjing43). A full-length cDNA of the cystatin gene was obtained by 3’/5’RACE (rapid amplification of cDNA ends). The cDNA sequence of this 627βbp clone contained an open reading frame encoding a polypeptide of 101 amino acid residues with a predicable molecular mass of 11.026βKDa. The deduced amino acid sequence contained the motif QXVXG conserved among most members of the cystatin superfamily. By using the program of Blast on GenBank database, the sequence presented a high match with the cystatin genes from other plants, such as European chestnut, Cassava, Cowpea, Tomato, Soybean et al. All researched out sequences were all cystatins, so we can conclude that the cloned sequence is a member of cystatin gene from Tea plant.
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  Isolation of Endophytic Antifungal and Pesticide Degrading Bacteria from Tea Plant

  HONG Yong-cong, XIN Wei, LAI Yu-bin, WENG Xin, HU Fang-ping

  Journal of Tea Science. 2005, 25(3): 183-188. https://doi.org/10.13305/j.cnki.jts.2005.03.005

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  The screening and identification of endophytic bacteria from the healthy and diseased leaves of various tea cultivar plants were conducted. Results showed that the endophytic bacteria were accounted in 2.9×10⁶~39.4×10⁶βcfu/(g•fw) in tea cultivars plants. The TL2 stain showed strongly antagonistic activity against leaf fungal pathogens of tea-plant. It showed a good protecting effect when inoculated the TL2 strain bacteria firstly than inoculated the tea grey blight pathogen(Pestallozzia theae) later, Besides, it showed a strong degrative activity to cypermethrin. The TL2 bacteria strain could colonize within tea plant. According to the results of identification, the TL2 bacteria strain was identified as bacillas subtilis.
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  Effect of Raw Material Processing Technology on Processing Characteristic of the Green Tea Beverage

  YIN Jun-feng, LIN Zhi, TAN Jun-feng, YUAN Hai-bo, YU Guang-bing

  Journal of Tea Science. 2005, 25(3): 189-196. https://doi.org/10.13305/j.cnki.jts.2005.03.006

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  Different raw materials made by different tender degree and processing technique was adopted to process green-tea beverage. The quality characteristic of beverage and the adaptability of different raw materials are studied by analyzing the dynamic changes of tea polyphenols, caffeine, amino acid, catechins, the chromaticity, the evaluation of organoleptic quality of tea beverage and a series of destructiveness experiment. A processing of raw materials which was suitable for green tea beverage was putted forward.
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  Variation of Polygalacturonase Activity and its Biochemical Effects in Zuoqing Stage of Oolong Tea New Techniques

  TANG Hao, YANG Wei-li, WEN Hai-tao

  Journal of Tea Science. 2005, 25(3): 197-202. https://doi.org/10.13305/j.cnki.jts.2005.03.007

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  In this trial, two tea cultivars named Meizhan and Maoxie were used in the investigation on the variation of polygalacturonase(PG) activity and soluble pectin contents in processing tea leaves during Zuoqing (new technique) and control(no Yaoqing ) treatments. Results showed that the activity of PG was increased slightly after Saiqing, it was gradually increased in the previous stage of Yaoqing and reached the peak in the completion of the 3^rd Yaoqing proccces. The PG activity showed significant variation between diffreret cultivars and various Yaoqing stage. The PG activity and the range of variation were significantly lower in the control than that in the Yaoqing treatment. A significant correlation between the control of water and soluble pectin, and the PG activity.
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  Study on the Influences of Microwave Pre-treatment on the Extraction Rate of Caffeine and EGCG from Green Tea with Supercritical-CO₂ Technology

  YU Hua-zhong, ZHOU Dong-wu, LI Guo-zhang, CAO Yong, LIU Sheng-kai, LONG Wei-zhen

  Journal of Tea Science. 2005, 25(3): 203-207. https://doi.org/10.13305/j.cnki.jts.2005.03.008

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  The influences of microwave pretreatment on the extraction rate of caffeine and EGCG from green tea with supercritical CO₂(SC-CO₂) extraction technology were analyzed. And through orthogonal experiments, the best parameter of decaffeination from tea with SC-CO₂ extraction technology was ascertained. The result showed that the decaffeination rate from the tea under microwave pretreatment could improve obviously, but the influences on EGCG was small, by using the orthogonal design test , the order of the influences factors on decaffeination rate of the caffeine is extracting pressure>Extracting temperature> entrainer>water content of the tea.
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  Genetic Toxicity Evaluation of Pu’er Tea

  CHEN Wen-pin, LIU Qin-ji, BAI Wen-xiang, LI Qing-ze

  Journal of Tea Science. 2005, 25(3): 208-212. https://doi.org/10.13305/j.cnki.jts.2005.03.009

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  The investigation on the safely evaluation based on the genetic toxicity was conducted on those three representative on Puer tea sample with one year, five years and ten years storage period produced by the factory of Yunnan by using the classical testing method and used the roasted green tea as the control. The results of mice bone marrow micronuclei test, the mice abnormal spermatozoon test and the Ames test of four tea samples showed negative reaction, Including no mutagenicity on primitive cells, authentic cells and reproductive cells by tested Pu’er tea and roasted green tea samples. The experiment excludes the mutagenicty including the chromosome breakage damage, gene base-pair substitution, and frame shift induced by Pu’er tea. Investigation also discovered that the test samples showed antagonic on the increase of micronucleus rate induced by other factors. Results showed that there four tea samples showed a higher safety to human cell and the Pu’er teas produced by the regular factory are safe to consumer.
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  Color Stability of Oxidation Products of Tea Polyphenols and Their Effects on the Growth of PC-3 Cells

  DING Zhao-tang, WANG Xiu-feng, YU Hai-ning, ZHANG Hui-yan, SHEN Sheng-rong

  Journal of Tea Science. 2005, 25(3): 213-218. https://doi.org/10.13305/j.cnki.jts.2005.03.010

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  In this paper, theaflavins extracts from black tea and green tea polyphenols were used as control, effects of oxidation products of green tea polyphenols catalyzed by nano-immobilization technique on the growth of PC-3 cells, their color stability and activity of scavenging free radicals were investigated by ultraviolet scanning technique MTT assay and Ultraviolet-vis method. The change of ultraviolet absorption spectrophometer of theaflavins extracts from black tea and nano-immobilized enzymatic in vitro oxidation products were alike The absorption increased along with pH increase. The theaflavins extracts from black tea, green tea polyphenols and enzymatic oxidation products possessed of the scavenging activity to DPPH·, and the scavenging activity of enzymatic oxidation products was higher than that of green tea polyphenols and theaflavins extracts. The growth of PC-3 cells were inhibited by theaflavins extracts from black tea and enzymatic oxidation products, and effects of enzymatic oxidation products were better than that of theaflavins extracts from black tea. The effective biological activity that is possessed in the theaflavin from black tea was preserved by the in vitro enzymatic oxidation products.
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  Study on the Hypoglycemic Mechanism of Tea Polysaccharides and Tea Polyphenols

  DING Ren-feng, HE Pu-ming, JIE Guo-liang

  Journal of Tea Science. 2005, 25(3): 219-224. https://doi.org/10.13305/j.cnki.jts.2005.03.011

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  The investigation on the hypoglycemic mechanism of tea polysaccharides and tea polyphenol in diabetic SD rats induced by alloxan was conducted. Methods: After feeding tea polysaccharides or polyphenols for 3 weeks, the changes of the level of blood glucose, insulin and the activities of amylase, sucrase and maltase in small intestine were inspected in diabetic rats. Results about that the suppressive effect of high level of blood glucose induced by alloxan was observed in the groups feeded with tea polysaccharides or tea polyphenols obviously in the experimental period. Compared with control group, the level of blood insulin in the group feeded with tea polysaccharides was increased significantly (P<0.05), the activity of sucrase and maltase were decreased significantly. Almost the same change without significance was observed in the group feeded with tea polyphenols while compared with the control group. Investigation indicated that the tea polysaccharides and tea polyphenols have remarkable suppressive hyperglycemic effect on diabetic rats induced by alloxan. These results suggested that functionary mechanisms of the suppressive hyperglycemic effect of tea polysaccharides may be induced by controlling the activities of sucrase and maltase.
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  Determination of Theanine in Tea by Reversed-Phase High Performance Liquid Chromatography-Evaporative Light-Scattering Detector

  LI Yin-hua, LIU Zhong-hua*, HUANG Jian-an, GONG Yu-shun

  Journal of Tea Science. 2005, 25(3): 225-228. https://doi.org/10.13305/j.cnki.jts.2005.03.012

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  High performance liquid chromatography (HPLC) coupled with evaporative light scattering detector（ELSD-2000）was used for the determination of theanine in tea without derivatization. A Polaris-C₁₈ column (250βmm×4.6βmm) was used with the mobile phase of 0.1%trifluoroacetic acid water solution and 0.1% trifluoroacetic acid acetonitrile solution .The flow rate was at 0.5βml/min. The linear response ranged from 0.062~0.450βmg/mL for theanine. The recovery was 97.5%. The method was evaluated as accurate and simple.
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  Study on the Optimum Conditions in Extracting Polysaccharides in Sichuan Brick Tea

  GONG Fa-yong, QI Gui-nian, LI Jing

  Journal of Tea Science. 2005, 25(3): 229-236. https://doi.org/10.13305/j.cnki.jts.2005.03.013

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  By means of orthogonally rotational combination design, a four-factor (temperature, time, ratio between tea and water, pH) substrate cultivation experiment was conducted by using of brick tea. The regression equations of the relationship between temperature, time, ratio between tea and water, pH and extraction rate of tea polysaccharides (TPS) were established. The results indicated that extraction rate of TPS was affected obviously in successive order by pH, temperature, ratio between tea and water and time. In range of experiment, extraction rate of TPS was increased obviously when pH and temperature were in higher levels, and the interaction of pH and temperature to the ratio between tea and water was significant, but the change of time and ratio between tea and water had less influence effects on extraction rate of TPS. Considering the high extraction rate and activity of TPS, the extraction conditions were optimized by frequency analysis that were 74.06~80.74℃temperature, 69.56~79.58βmin time, 38.49~42.59 ratio between tea and water, 7.411~8.284 pH.