【作者】 樊蓉；

【导师】 倪德江；

【作者基本信息】 华中农业大学 ， 茶学， 2007， 硕士

【摘要】 普洱茶属于后发酵茶，是我国特有的一类茶，有很大的市场发展潜力。本实验首次以云南野生大茶树原料制作的普洱茶为材料，对普洱茶多酚氧化产物的提取分离工艺进行了研究，并探索其降血脂、抗氧化的功能，旨在系统、全面地研究和科学地评价普洱茶，为普洱茶深加工技术改进和产业化发展提供理论支持，为普洱茶功能食品的开发提供科学依据。1普洱茶多酚氧化产物浸提工艺的研究及其提取物主要品质成分分析以普洱茶为原料，研究溶剂pH值、浸提温度、时间、料液比对茶褐素（TBS）提取率的影响。结果表明，溶剂pH值、浸提温度、时间、料液比等都显著影响TBS的浸提效果，其中料液比、浸提温度、浸提时间达到了极显著水平，其影响效果的重要性依次为：料液比＞浸提温度＞浸提时间＞溶剂pH值。同时得到茶褐素浸提的优化条件为：温度100℃，溶剂pH=7，料液比1：30，时间20min。发酵是影响普洱茶品质成分变化的主要原因。普洱茶所含的化学成分与其原料相比差异较大，普洱茶中茶多酚、没食子酸、氨基酸（尤其是茶氨酸）含量远低于晒青绿茶，茶黄素、茶红素、茶褐素含量以及可溶性糖含量则高于晒青绿茶。茶多酚在普洱茶中主要以简单儿茶素的形式存在，而在晒青绿茶中则主要以酯型儿茶素形式存在。主要品质成分没食子酸、茶氨酸和咖啡碱在普洱茶多酚氧化产物中的分布差异较大。没食子酸主要存在于TFS，茶氨酸主要存在于TRS和TBS，咖啡碱主要存在于TFS和TRS。2普洱茶及其多酚氧化产物的降血脂功能研究以晒青绿茶提取物（GE）为对照，分别以高、中、低不同剂量的普洱茶水提物（PE）、茶黄素（TFS）、茶红素（TRS）和茶褐素（TBS）灌胃高脂模型小鼠，40天后眼眶取血、分离肝组织，测血脂指标。结果表明：（1）普洱茶及其多酚氧化产物能有效调节预防性高脂小鼠血清血脂水平。TBS中高剂量、PE各剂量对高脂小鼠血清TC含量有极显著的降低作用。TRS、TBS、PE各剂量组都能极显著的降低小鼠血清TG含量，普洱茶效果好于其多酚氧化产物。除PE中低剂量组外其他供试品各剂量组均能极显著的增加HDL-C含量，TFS、TRS组效果最好。（2）普洱茶及其多酚氧化产物对预防型高脂小鼠肝匀浆血脂调节作用主要体现于TG、TC含量的降低。TRS各剂量组，PE各剂量组能有效预防肝匀浆中TC升高，除TRS高剂量外其余各组都显著降低肝匀浆中TG含量，且茶汤提取物效果较其他单独多酚氧化产物效果显著。小鼠肝脏切片显示，灌胃组能有效防止高脂肝细胞正常组织结构消失程度。（3）普洱茶原料晒青绿茶降低血脂的效果优于普洱茶。表现在晒青绿茶组TC、TG含量最低，并且比普洱茶及其多酚氧化产物明显降低血清TC含量。3普洱茶及其多酚氧化产物的抗氧化活性研究按上述同样的方法分析普洱茶及其多酚氧化产物的体内外抗氧化作用。结果表明：（1）普洱茶及其多酚氧化产物能显著增强预防型高脂小鼠血清及肝脏的抗氧化功能。PE组，TBS高剂量组、TFS中剂量组能极显著提高血清SOD活力，各供试组均能极显著地提高肝脏SOD活力。各供试组都能极显著的降低血清MDA含量，其中以TRS对小鼠血清MDA生成影响最显著，但在肝脏中仅PE高剂量组能有效降低MDA含量。（2）普洱茶及其多酚氧化产物在体外对O₂·^-自由基有较强的清除活性。其清除O₂·^-自由基的成份主要集中在TFS部分，清除能力大小依次为TFS＞TRS＞TBS＞PE。（3）绿茶的抗氧化活性优于普洱茶。主要表现在体内能显著提高预防性高脂小鼠SOD活力，降低MDA含量，体外对O₂·^-自由基有较强的清除能力。更多还原

【Abstract】 Pu’er tea is post fermented tea, a special tea with much market-developingpotential in China. The method of extraction and isolation of polyphenol Oxides fromPu’er tea was studied in my project; also we studied its effect on rat’s blood lipids andantioxidant capacity. This is the first experiment on the material of Yunnan wild tearaw. In order to study it comprehensively, evaluate it scientifically, and provideintensive processing technology and industrial development theories. Also we mayguide the development of functional foods, the consumers’ choice and the teaconsumer market.1. Study on extraction technology of polyphenol oxides and main qualitycomponent from Pu’er teaThe influence of pH value of solvent, temperature, heating time and ratio of teato solvent on extraction rate of TBS was studied. The results showed that allparameters affected the extraction rate noticeably, and the effects of last threeparameters was extremely remarkable. The order of importance was: ratio of tea tosolvent＞temperature＞heating time＞pH value of solvent. The optimized parameterswere: using pH=7 water solution as extract solvent, the ratio of tea to solvent was 1:30,and extracting at 100℃for 20min.Fermentation was the main influence factor of Pu’er tea quality. Pu’er teachemical contents had much difference with its material raw. Tea polyphenol, gallicacid, amino acids （in particular theanine） was much lower in Pu’er tea, while TFS,TRS, TBS and soluble sugar content was higher than the drying green tea. The maincatechins of Pu’er tea were simple catechins, while the drying green tea catechinswere complex catechins. The distribution of gallic acid, theanine and caffeine in Pu’ertea polyphenol oxides was quit difference. Gallic acid was found primarily in the TFS,while theanine in the TRS and TBS, and Caffeine in the TFS and TRS.2. Study on Pu’er tea and its polyphenol oxides on reducing blood lipidsUsing the drying green tea extraction （GE） as a control, hyperlipidemia modelmice were intragastric Infusion with different dose of TFS, TRS, TBS, PE and GE for40 days. After last administration, he mice were fasted at least 10 hours, and then theywere sacrificed by cervical dislocation, serum was prepared from blood obtained ineye vein cluster and TC,TG,HDL-C,MDA and SOD were assayed; The liver washomogenized in physiology saline and TC, TG, MDA and SOD were assayed. Theresults were showed:（1） Pu’er tea and its polyphenol oxides can be effectively regulated preventivehigh fat mice serum lipid level. TBS with medi-dose, high-dose and each dose of PE could remarkably decrease the content of TC; TRS, TBS and PE at all doses couldsignificantly lower the content of TG, the effect of Pu’er tea was better than itspolyphenol oxides; All the tasted samples could increase HDL-C contents of serumsignificantly except PE medi-dose and low dose, and the effect of TFS, TRS wasbetter than others.（2）The regulative effect on high-fat mice liver of Pu’er tea and its polyphenoloxides was mainly reflected in the decreased of TG, TC content; Each dose of TRSand PE could prevent the increase of TC content effectually on the liver of high-fatmice, and all doses of tasted samples except high dose of TRS could significantlyreduced liver triglyceride content of high-fat diet mice, and the effect of PE was betterthan its polyphenol oxides. The liver biopsy of high-fat group showed that: theexperimental groups can be effective in preventing the disappear extent of high-cellsof normal liver structure.（3）The Green tea had more effect on reducing blood lipids than Pu’er tea. As theGE group had the lowest content of TC and TG, and GE can reduce the TC contentmuch more significantly than other samples.3. The effect of Pu’er tea and its polypheuol oxides on antioxidant abilityThe antioxidant activity of TFS, TRS, TBS, TA and green tea extracts wasstudied. The results showed:（1）Pu’er tea and its polyphenol oxides can significantly enhance the preventivehigh-fat mouse serum and liver antioxidant function. PE group, TBS medi-dose,high-dose groups, TFS medi-dose group could significantly increase the SOD activityof serum, and all the samples could significantly raise the SOD activity of liver. Allthe test groups can significantly reduce the content of MDA in serum, and TRS hadthe most significant impact, but only high-dose of PE could effectively reduce thecontent of MDA significantly in the liver.（2）Pu’er tea and its polyphenol had strong activity in vitro oxides of O₂·-radicalscavenging. The removal of oxygen-free radicals ingredients mainly concentrated inthe TFS, the order of removing ability was: TFS＞TRS＞TBS＞PE.（3） The antioxidant activity of Green tea was better than the Pu’er tea. Mainlybecause of that it can significantly improve the SOD activity and lower MDA contentof preventive high fat mice in the body, and its strong scavenging capacity of O₂·^-.更多还原