Journal of Tea Science

Advances in Researches on Catechins Acylation Modification

LIU Xiao-hui, JIANG He-yuan, ZHANG Jian-yong, YUAN Xin-yue, CUI Hong-chun

Journal of Tea Science. 2009, 29(1): 1-8. doi:10.13305/j.cnki.jts.2009.1.001

Abstract ( 507 )

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Researchers and the general public have been paid more and more attention to catechins due to their distinctive and extensive bioactivities, but the further applications are restricted because its liposoluble is not high, unstability and low bioavailability in vivo. This paper reviewed the research progress of acylation modificated catechins and their physiological activities as well as the prospects of development．

Effect of Al and F Interaction on the Tea Quality

WANG Xiao-ping, LIU Peng, LUO Hong, XIE Zhong-lei, XU Gen-di, CHEN Li-jun

Journal of Tea Science. 2009, 29(1): 9-14. doi:10.13305/j.cnki.jts.2009.1.002

Abstract ( 453 )

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In this research, quality of tea leaves to aluminum (Al) and fluorine (F) interaction were studied, and five indices (polyphenols, caffeine, free amino acids, vitamin C and chlorophyll concentrations) in tea leaves (variety Anji Baicha and zhirenzaocha) were investigated after 30 d in hydroponic culture. The nutrient solution was treated by the interaction of Al (0, 30, 90 mg/L) and F (0, 4, 12 mg/L). The results were summarized as follows: With 30 mg/L of the single Al, the contents of polyphenols, caffine, free amino acids, vitamin C and chlorophyll in tea leaves were increased. But when the concentration of Al was 90 mg/L, the contents of above components in tea leaves were decreased. These components in tea leaves were increased under the treatment of 4 mg/L of the single F and decreased with the treatment of 12 mg/L of the single F. In the process of aluminum and fluorine interaction, the contents of these components in tea leaves of Anji Baicha were increased during the treatments of Al/F ratioin 30/4, 30/12, 90/4 and 90/12. However, zhirenzaocha were decreased. The results showed that tea quality improved in low concentration of aluminum or fluorine. Meanwhile, the variance effect of interaction was correlated to different proportion of Al/F and the proportion of Al/F for better quality of Anji Baicha and zhirenzaocha was different indicating there existed a varietal difference.

Determination of Melamine in Milk Tea By High Performance Liquid Chromatography

JIANG He-yuan, YUAN Xin-yue, ZHANG Jian-yong, CUI Hong-chun, LIU Xiao-hui, YAO Yu

Journal of Tea Science. 2009, 29(1): 15-19. doi:10.13305/j.cnki.jts.2009.1.003

Abstract ( 650 )

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The method to determinate melamine in milk tea by HPLC, was established. The samples were analyzed by a Sunfire C₁₈ column （250 mm×4.6 mm ID; 5 μm）. The mobile phase was composed of 0.008 mol/L sodium 1-Octanesulfonate （adjust to pH3.3 with acetic acid） and acetonitrile. The flow rate was 1.0 ml/min. Column temperature was 30℃. UV-detection was performed at 236 nm. The contents were quantified with exterior standard. Some milk tea samples from the supermarket were analyzed, and results showed that the content of melamine in some milk tea were higher than 2.5 mg/kg, the set limit in national standard.

Determination of Theanine in Tea by High Performance Liquid Chromatography-Atmospheric Pressure Chemical Ionization Mass Spectrometry

WANG Hong, KANG Hai-ning, CHEN Jun-hui, ZHAO Heng-qiang, WANG Xiao-ru, Frank Sen-Chun Lee

Journal of Tea Science. 2009, 29(1): 20-26. doi:10.13305/j.cnki.jts.2009.1.004

Abstract ( 564 )

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HPLC coupled online with atmospheric pressure chemical ionization MS technique was developed for the qualitative and quantitative determination of theanine in tea. The theanine and other compounds in the tea extract were separated on an Alltima C₈ column with methanol and water (10:90 v/v) as mobile phase, with flow rate of 0.6 ml/min and APCI-MS SIM m/z 175.1 detection. In the positive APCI mode, sensitive and stable MS signal could be obtained by APCI-MS (SIM m/z 175.1) detection, and the APCI-MS conditions were also optimized by orthogonal design. The results indicated that HPLC-APCI-MS method was simple, sensitive and reliable for the determination of theanine in tea. It was important that the detection sensitivity was improved greatly by APCI-MS than UV. Eight tea samples from Fujian province were analysed using the established methods.

Application of Bayes Stepwise Discrimination Analysis on Chemical Recognition of Green Tea with Chestnut-like Aroma

YE Guo-zhu, YUAN Hai-bo, JIANG Yong-wen, YIN Jun-feng, WANG Fang, CHEN Jian-xin

Journal of Tea Science. 2009, 29(1): 27-33. doi:10.13305/j.cnki.jts.2009.1.005

Abstract ( 537 )

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The teas are classified into two categories—teas with chestnut-like aroma and other ones without chestnut-like aroma, according to the organoleptic evaluation results carried out by experienced experts. The screening process was conducted on the common components of teas with chestnut-like aroma along with the Bayes stepwise screening process, and set the aromatic components after screening as the variables. Then the discrimination equation was established. Results of cross-validation and validation of testing samples demonstrated that the correct rates of discrimination equation, established by cis-jasmone and geranylacetone, reached 94.44% in both discrimination analysis and cross-validation of training dataset, and the 8 testing samples are judged correctly, the correct rates of discrimination was 100%, Thus, it can be concluded that the discrimination equation worked effectively and the results was satisfactory. In addition, it can be seen that the chestnut-like aroma could be distinguished effectively by the selected variables in the principal components figure of cis-jasmone and geranylacetone.

Recognition of Wuyi Zheng Yan Tea with PLS-DA Based on Leverage Correction Using near Infrared Spectra

ZHOU Jian, CHENG Hao, WANG Li-yuan, XUE Feng-ren, HE Xiao-yan, XU Jin-bin, HE Wei

Journal of Tea Science. 2009, 29(1): 34-40. doi:10.13305/j.cnki.jts.2009.1.006

Abstract ( 708 )

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Wuyi Yan tea was one of Olong tea which was produced only in north of Fujian province. It was a famous tea in China and the quality of Zheng Yan tea which was manufactured of tea leaves planted in the centre area of Wuyi mountain was best in Wuyi Yan tea. To recognize Zheng Yan tea , Partial least Squares Discriminant Analysis（PLS-DA）combined with leverage correction was used to discriminate Zheng Yan tea and Ban yan tea based on near-infrared spectra in this paper. The result showed that Zheng Yan tea could be recognized by PLS-DA method. 100% was correctly recognized in training set(42 samples), test set(20 samples) separately. The result proved the feasibility of discriminant recognition of Zheng Yan tea and Ban Yan tea.

Research on the Anti-diabetes and Anti-hyperlipidenmia Function of Monomers in Pu-erh Tea

ZHANG Dong-ying, SHAO Wan-fang, LIU Zhong-hua, LIU Ya-lin, HUANG Ye-wei

Journal of Tea Science. 2009, 29(1): 41-46. doi:10.13305/j.cnki.jts.2009.1.007

Abstract ( 571 )

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The anti-diabetes and anti-hyperlipidenmia function of Uracil and Gallic acid from Pu-erh Tea was studied by the PPARδ, PPARα, PPARγ, FXR, LXR, 3T3-L1 and α-amylase models which are related to glucose and lipid metabolism. Result showed that: Uracil and gallic acid were active to the models of PPARγ, FXR, LXR, especially, Gallic acid showed distinct active effect on PPARγ, the value was as high as 2.438 which showed the same effect as positive drug, and weak activity on PPARδ, PPARα, 3T3-L1 models. Gallic acid showed better activity than Uracil in the PPARγ model and Uracil showed better activity than gallic acid in the FXR and LXR models. Furthermore, Gallic acid showed strongth inhibition on the activity of α-amylase. It can provide some theoretical basis on the mechanism of Pu-erh tea on the anti-diabetes and anti-hyperlipidenmia activity.

Molecular Cloning and Expression of a Flowering-related Calcium-dependent Protein Kinase Gene in Tea Plant [Camellia sinensis (L.)O.Kuntze]

CHEN Xuan, TANG Cha-qin, ZOU Zhong-wei, YANG Yi-yang, FANG Wan-ping, WANG Yu-hua, LI Xing-hui

Journal of Tea Science. 2009, 29(1): 47-52. doi:10.13305/j.cnki.jts.2009.1.008

Abstract ( 402 )

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To have an insight into the comprehensive molecular characteristics relating to the flower development mechanisms of tea plant [Camellia sinensis (L.)O.Kuntze], cDNA-AFLP (Amplified Fragment Length Polymorphism) was performed within two tea plant cultivars, Longjin43 and Daye Wulong. A cDNA fragment encoding a calcium-dependent protein kinase gene was isolated and identified. The complete cDNA sequence was cloned by RACE (rapid amplification of cDNA ends), named TCK(Camellia sinensis calcium-dependent protein kinase)gene. GenBank accession number is EU732607. To identify differential expression of TCK gene, RT-PCR experiments were performed in six samples including leaves, small flower buds and big flower buds of Longjing 43 and Daye Wulong. Results showed that the expect band exists in the big flower buds, no band in leaves and small flower buds of these two cultivars. It hinted that TCK might play a key role during flower development of tea plant.

Cloning and Expression Analysis of CBF Gene in Cold Induced Tea Plant [Camellia Sinensis (L.)O.Kuntze]

CHEN Xuan, FANG Wan-ping, ZOU Zhong-wei, WANG Yu-hua, CHENG Hao, LI Xing-hui

Journal of Tea Science. 2009, 29(1): 53-59. doi:10.13305/j.cnki.jts.2009.1.009

Abstract ( 505 )

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The cDNA-AFLP was applied to identify genes expressed differentially in cold acclimatized tea plant. A cDNA fragment, TDF11 encoding a CBF (C-repeat binding factor) protein was isolated and identified. The cDNA fragment had 94%、84%、81% homology with CBF genes from Brassica napus, Arabidopsis thaliana, Nicotiana tabacum by BLAST on NCBI. The complete cDNA sequence was cloned by RACE (rapid amplification of cDNA ends), named Camellia sinensis CBF gene. Its full cDNA sequence was 981bp (GenBank accession number EU857638) and contained an open reading frame encoding a polypeptide of 275 amino acid residues. Analysis of the nucleotide sequence and deduced amino acid sequence showed 74%、57%、57% homology with CBF genes from Brassica napus, Nicotiana tabacum, Arabidopsis thaliana. To identify differential expression of CBF gene, RT-PCR experiments were performed in six samples including leaves cold-induced for different treatments. The results showed that tea CBF gene expressed after cold induced for 4 hours and up to a maximum when cold induced for 8 h, and then decreased. It hinted the CBF gene might play a key role during the development of cold resistant molecular mechanism in tea plant.

Relationship between Leaf Structure of Tea Germplasm and Its Resistance to Aleurocanthus spiniferus (Quaintance)

WANG Qing-sen, HUANG Jian, CHEN Chang-song, WU Guang-yuan, ZENG Ming-sen, HUANG Chun-mei, CHEN Rong-bing

Journal of Tea Science. 2009, 29(1): 60-66. doi:10.13305/j.cnki.jts.2009.1.010

Abstract ( 418 )

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Using field pest density and the number of oviposition per unit area and the generational survival rate of A. spiniferus in laboratory as indexes, the resistance of 12 tea germplasm to A. spiniferus was studied. Relationships between leaf structure of 9 tea germplasms and the oviposition numbers of A. spiniferus and its generational survival rate were analyzed. The results showed that the resistance of You 510, You 3, Dangui, Yulong, Jiulongpao to A. spiniferus was stronger than that of G31, Baijiguan, Fuyun No.10 and Tieguanyin. The oviposition numbers of A. spiniferus was found to have significantly positive correlation with stoma density(R=0.7950, F=12.0267, P=0.0104) and thickness of spongy tissue(R=0.6790, F=5.9890, P<0.05), have significantly negative correlation with thickness of palisade tissue(R=-0.7187, F=7.4784, P<0.05) and nearly significantly negative correlation with thickness of cuticular layer on subepidermis(R=-0.6439, F=4.9591, P=0.0613). Meanwhile, the generational survival rate of A. spiniferus have nearly remarkably positive correlation with stoma density(R=0.6654, F=5.5605, P=0.0505), but extremely-marked negative correlation with thickness of subepidermis(R=-0.8390, F=16.6361, P<0.01), and extremely-marked negative correlation with cuticular layer on subepidermis(R=-0.7843, F=11.1886, P=0.0123), and extremely-marked negative correlation with thickness of palisade tissue(R=-0.8109, F=13.4414, P<0.01).

A Method for Determination of Imidacloprid Residue in Tea with HPLC-UV

HOU Ru-yan, ZHU Xu-jun, ZHANG Zheng-zhu, CAI Hui-mei, WAN Xiao-chun

Journal of Tea Science. 2009, 29(1): 67-71. doi:10.13305/j.cnki.jts.2009.1.011

Abstract ( 597 )

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A method was developed for determination of imidacloprid residue in tea by high performance liquid chromatography (HPLC) with UV detector. Imidacloprid in tea samples was extracted with methyl alcohol and re-extracted by dichloromethane then cleaned up with the ENVI-18 cartridge. Imdacloprid was eluted with acetonitrile:water(v/v, 30:70) solution from the cartridge and detected with HPLC. The recovery of imidacolprid ranged from 81.5%~87.9% with the RSD less than 10.2%. Practical determination limit was 0.05 mg/kg.

Re-analysis of the Phenomena and Causation of Flourishing Tea Culture in Tang Dynasty

JIA Yue-qian, BAO Gong-min, ZHU Jian-qing

Journal of Tea Science. 2009, 29(1): 72-78. doi:10.13305/j.cnki.jts.2009.1.012

Abstract ( 548 )

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The paper re-analyzes the phenomena and causation of flourishing tea culture in Tang dynasty in China, which would help to clarify amphibolous view whether tea culture was first flourishing in Tang dynasty (A.D. 608~907) or North Song dynasty (A.D. 960~1127). The authors point out that Tang dynasty is a landmark time in the formation of tea culture and set the base tone of the subsequent development of tea culture. The paper lists six initial phenomena of flourishing tea culture in Tang dynasty and indicates six possible causations.

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