發(fā)布時(shí)間：2018-11-20 17:52

【摘要】：茶作為中國(guó)傳統(tǒng)飲品已有千年歷史。綠茶是我國(guó)產(chǎn)量最多的一種茶且倍受人們喜愛(ài)。近年來(lái)的研究表明,綠茶提取物具有抗氧化、抗腫瘤、抗炎、降低心血管疾病患病風(fēng)險(xiǎn)等功效。影響綠茶品質(zhì)的主要因素有:茶樹(shù)品種以及綠茶產(chǎn)地的地表溫度、平均降水量、海拔高度和日照時(shí)長(zhǎng)等�，F(xiàn)行的綠茶國(guó)家標(biāo)準(zhǔn)存在標(biāo)齡較長(zhǎng),分析手段落后且耗時(shí)較長(zhǎng),評(píng)價(jià)指標(biāo)不夠完善等問(wèn)題。如何建立可全面表征綠茶中化學(xué)成分的分析方法,如何高效、快速、準(zhǔn)確地評(píng)價(jià)綠茶的質(zhì)量是當(dāng)前綠茶研究中亟待解決的現(xiàn)實(shí)問(wèn)題。本研究以云南和湖南的綠茶為研究對(duì)象,采用超高效液相色譜-高分辨質(zhì)譜聯(lián)用技術(shù)對(duì)綠茶的化學(xué)成分進(jìn)行了詳細(xì)研究,主要的研究?jī)?nèi)容包括以下幾個(gè)方面:1.采用超高效液相色譜-高分辨質(zhì)譜聯(lián)用技術(shù)對(duì)采集自云南和湖南的共72批綠茶進(jìn)行分析。本研究對(duì)不同的提取溶劑(純水、純甲醇、70%甲醇)和不同的綠茶樣本用量(0.1g、0.5g、1.0g)進(jìn)行了比較和優(yōu)化。結(jié)果表明,采用70%甲醇提取0.5g綠茶樣本的效果最佳。為獲取更為豐富的質(zhì)譜信息,對(duì)實(shí)驗(yàn)的質(zhì)譜條件包括源內(nèi)誘導(dǎo)裂解電壓和高能碰撞誘導(dǎo)電壓等進(jìn)行了優(yōu)化選擇。為避免獲取前體離子時(shí)產(chǎn)生過(guò)多的干擾碎片,源內(nèi)誘導(dǎo)裂解電壓選擇為OeV。同時(shí),為獲取更多的二級(jí)碎片,高能碰撞誘導(dǎo)電壓采用梯度電壓(10eV、30eV、50eV)。最后,為保證實(shí)驗(yàn)儀器在分析過(guò)程中的穩(wěn)定性,利用混標(biāo)及質(zhì)控樣本進(jìn)行了精密度和穩(wěn)定性等方法學(xué)考察。結(jié)果表明,在整個(gè)實(shí)驗(yàn)過(guò)程中,實(shí)驗(yàn)儀器穩(wěn)定、可靠。2.綠茶中化學(xué)成分的定性定量分析。采用MZmine質(zhì)譜分析軟件對(duì)獲取的質(zhì)譜數(shù)據(jù)進(jìn)行提取及分析。為盡可能多的提取有效質(zhì)譜,對(duì)質(zhì)譜分析軟件的參數(shù)設(shè)置進(jìn)行優(yōu)化,包括峰校正、峰檢測(cè)、峰提取、解卷積、峰對(duì)齊等過(guò)程中的峰高、峰寬、噪音水平等參數(shù)進(jìn)行選擇優(yōu)化。研究發(fā)現(xiàn)噪音水平是最為關(guān)鍵的參數(shù)。經(jīng)綜合分析,噪音水平選擇在5.00E8時(shí)既可以排除背景干擾又可以最大限度保留有效質(zhì)譜信息。在此基礎(chǔ)上,利用標(biāo)準(zhǔn)物質(zhì)、多個(gè)質(zhì)譜數(shù)據(jù)庫(kù)和化學(xué)數(shù)據(jù)庫(kù)中的一級(jí)和二級(jí)質(zhì)譜信息匹配,在兩地綠茶中共定性出包括兒茶素類(lèi)、黃酮類(lèi)、氨基酸等75種化合物,其中33種化合物經(jīng)標(biāo)準(zhǔn)品進(jìn)行確認(rèn)。本研究以這75種化合物為綠茶化學(xué)特征成分群,采用內(nèi)標(biāo)法進(jìn)行半定量分析,并建立了兩地綠茶的定量色譜指紋圖譜。研究表明,盡管兩地綠茶的化學(xué)指紋圖譜極為相似,但各物質(zhì)含量卻存在一定差異。3.云南和湖南產(chǎn)綠茶的差異性分析。首先,采用聚類(lèi)分析和主成分分析兩種無(wú)監(jiān)督模式識(shí)別方法對(duì)云南和湖南產(chǎn)綠茶進(jìn)行區(qū)分。結(jié)果表明,這兩種方法均能對(duì)該兩地綠茶進(jìn)行有效地區(qū)分。在此基礎(chǔ)上,采用偏最小二乘-判別分析(PLS-DA)結(jié)合三種變量選擇方法(VIP、coefficient β、Lasso)對(duì)云南和湖南綠茶進(jìn)行判別分析。結(jié)果表明,PLS-DA結(jié)合VIP法建立的模型具有最佳的判別能力,能夠很好地區(qū)分云南綠茶和湖南綠茶,判別正確率為90.28%。通過(guò)VIP篩選出的三個(gè)特征差異性成分是 Epicatechin-(4beta-8)-epigallocatechin 3-O-gallate,沒(méi)食子兒茶素沒(méi)食子酸酯(GCG),牡荊素。其中,云南和湖南綠茶中沒(méi)食子兒茶素沒(méi)食子酸酯的含量差異最為明顯。
[Abstract]:Tea, as a traditional Chinese drink, has a thousand years of history. Green tea is one of the most productive teas in our country and is popular for people. The research in recent years has shown that the green tea extract has the effects of resisting oxidation, resisting tumor, resisting inflammation, and reducing the risk of cardiovascular disease. The main factors that affect the quality of green tea include the tea varieties and the surface temperature, the average precipitation, the altitude and the length of the green tea. The current national standard of green tea has the problems of long age, backward analysis method, long time consumption and insufficient evaluation index. How to establish an analytical method to fully characterize the chemical components in green tea, how to efficiently, quickly and accurately evaluate the quality of green tea is the real problem to be solved in the present study of green tea. The chemical constituents of green tea from Yunnan and Hunan were studied in detail. The main contents of this study were as follows: 1. A total of 72 green tea collected from Yunnan and Hunan were analyzed by ultra-high performance liquid chromatography-high resolution mass spectrometry. In this study, different extraction solvents (pure water, pure methanol, 70% methanol) and different amounts of green tea samples (0.1g, 0.5g, 1.0g) were compared and optimized. The results showed that 0. 5g of green tea samples were extracted with 70% methanol. In order to obtain more abundant mass spectrum information, the optimized selection of the mass spectrum conditions of the experiment, including the induced cracking voltage in the source and the high-energy collision-induced voltage, was selected. In order to avoid excessive interference fragments generated at the time of obtaining the precursor ions, the induced cracking voltage in the source is selected to be OeV. At the same time, in order to obtain more secondary fragments, the high-energy collision induced voltage is a gradient voltage (10eV, 30eV, 50eV). Finally, in order to ensure the stability of the experimental apparatus during the analysis, the precision and the stability of the quality control samples were studied. The results show that the experimental apparatus is stable and reliable throughout the experiment. Qualitative and quantitative analysis of the chemical constituents in green tea. The obtained mass spectrum data was extracted and analyzed by using the MZmine mass spectrum analysis software. In order to extract the effective mass spectrum as much as possible, the parameter setting of the mass spectrum analysis software is optimized, including peak correction, peak detection, peak extraction, deconvolution, peak alignment, etc., and the parameters such as peak height, peak width and noise level are selected and optimized. The study found that the noise level is the most critical parameter. Through the comprehensive analysis, the noise level is selected to be 5.00E8, the background interference can be eliminated, and the effective mass spectrum information can be kept to the maximum extent. On this basis, 75 compounds, including catechins, flavonoids, amino acids and the like, were identified in green tea by using standard substance, mass spectrum database and primary and secondary mass spectrum information in the chemical database, and 33 of the compounds were confirmed by standard products. A quantitative chromatographic fingerprint of green tea in two places was established by using the 75 compounds as a group of chemical constituents of green tea, using internal standard method to carry out semi-quantitative analysis. The results show that although the chemical fingerprints of green tea in the two places are very similar, there are some differences in the content of each substance. The difference of green tea in yunnan and hunan. First, using cluster analysis and principal component analysis, two unsupervised pattern recognition methods were used to distinguish the green tea from Yunnan and Hunan. The results show that the two methods can be used to separate the green tea from the two places. On this basis, the discriminant analysis of green tea in Yunnan and Hunan was carried out by using partial least squares-discriminant analysis (PLS-DA) in combination with three variable selection methods (VIP, coeffciant, and Lasso). The results show that the model of the PLS-DA combined with the VIP method has the best judgment ability, and can be divided into Yunnan green tea and Hunan green tea in a good area, and the discrimination rate is 90. 28%. The three characteristic difference components screened by VIP are Epicatechin-(4beta-8)-epiallocatorin 3-O-gallate, epigallocatechin gallate (GCG), and vitexin. Among them, the content of gallocatechin gallate is most obvious in Yunnan and Hunan green tea.
【學(xué)位授予單位】：昆明理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TS272.51;O657.63

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 ZHUANG XinGang;WANG LiLi;CHEN Qi;WU Xue Yuan;FANG JiaXiong;;Identification of green tea origins by near-infrared(NIR) spectroscopy and different regression tools[J];Science China(Technological Sciences);2017年01期

2 尹貽珍;李燕文;韓慧琴;宮曉平;曾春萍;;不同產(chǎn)地蘋(píng)果花薄層色譜及特征圖譜研究[J];現(xiàn)代中藥研究與實(shí)踐;2016年04期

3 何健安;莫曉君;甘靜妮;;氣相色譜-三重四極桿串聯(lián)質(zhì)譜檢測(cè)綠茶中八氯二丙醚(S-421)殘留[J];廣東化工;2016年10期

4 吳易峰;;氣相色譜-串聯(lián)質(zhì)譜(GC-MS/MS)法測(cè)定茶葉中20種農(nóng)藥殘留[J];武夷科學(xué);2015年00期

5 劉慧;;綠茶及茶多酚藥理作用研究進(jìn)展[J];安徽農(nóng)業(yè)科學(xué);2014年28期

6 康明艷;李?lèi)?魏文靜;靜寶元;;高效液相色譜法測(cè)定茶葉中的茶多酚[J];食品研究與開(kāi)發(fā);2014年15期

7 劉爽;譚俊峰;林智;魯成銀;王瀟;;電子舌技術(shù)在綠茶感官審評(píng)及等級(jí)評(píng)價(jià)中的應(yīng)用[J];中國(guó)茶葉;2014年05期

8 曹學(xué)麗;宋沙沙;龍立梅;;綠茶品質(zhì)及其審評(píng)方法的研究進(jìn)展[J];食品科學(xué)技術(shù)學(xué)報(bào);2014年01期

9 周燦;;綠茶的種類(lèi)及功效[J];林業(yè)與生態(tài);2013年03期

10 劉琨;錢(qián)和;汪何雅;;茶葉中多酚氧化酶提取的響應(yīng)面優(yōu)化[J];食品科技;2013年01期

相關(guān)會(huì)議論文 前1條

1 王漢生;;茶葉的藥理成分與人體健康[A];2005廣東茶產(chǎn)業(yè)發(fā)展論壇匯編[C];2005年

相關(guān)博士學(xué)位論文 前2條

1 賀巍;基于化學(xué)指紋圖譜的茶葉產(chǎn)地、原料品種判別分析和生化成分預(yù)測(cè)[D];南京農(nóng)業(yè)大學(xué);2011年

2 金惠淑;茶葉品質(zhì)化學(xué)和儀器鑒定研究[D];浙江大學(xué);2007年

相關(guān)碩士學(xué)位論文 前2條

1 王敏;固相萃取技術(shù)和高效液相色譜串聯(lián)質(zhì)譜聯(lián)用在茶葉中農(nóng)藥殘留檢測(cè)中的應(yīng)用[D];安徽大學(xué);2013年

2 陸瑋潔;茶葉~1HNMR指紋圖譜雙指標(biāo)序列分析及其葉表皮微形態(tài)特征的研究[D];山東大學(xué);2008年

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