【作者】 周继荣；

【导师】 倪德江；

【作者基本信息】 华中农业大学 ， 植物学， 2004， 硕士

【摘要】 鹿苑茶为湖北省远安县历史名茶，属黄茶类。本课题以鹿苑茶为对象，在研究传统鹿苑茶品质形成机理的基础上，优化闷黄条件和做形工艺，实现了鹿苑茶加工全程机械化。 探明了传统鹿苑茶加工过程中主要生化成分和色泽的动态变化。随着加工的进程，茶多酚逐渐减少，氨基酸、可溶性糖和蛋白质含量呈先增后减趋势，茶黄素、茶红素和茶褐素含量呈增加趋势。用高效液相色谱法对儿茶素组分进行了分析。结果表明，在鹿苑茶加工过程中，EGCG和ECG含量减少，简单儿茶素C和EC含量增加。叶绿素分析结果表明，叶绿素a、叶绿素b和总叶绿素含量随加工的进程减少。首次将色差计法引入黄茶色泽分析。结果表明，鹿苑茶干茶和茶汤a*值均为负值，随加工的进程而增加，绝对值减少；干茶和茶汤b*值都为正值，其中干茶b*值随加工的进程而减少，茶汤b*值的变化趋势则相反。 闷黄试验结果表明，随着闷黄温度的升高和时间的延长，茶叶黄色度增加，绿色度和亮度下降，香气和滋味水闷味加重。茶叶含水量、闷堆温度和时间对茶多酚、叶绿素的影响达到极显著水平，而对蛋白质、氨基酸、可溶性糖的影响较小，茶多酚、叶绿素含量随茶叶含水量、闷堆温度以及时间的增加呈下降趋势。结合感官审评结果和内含品质成分的变化，鹿苑茶最佳闷黄条件为：茶叶含水量40—50％，闷堆温度35℃左右，闷堆时间4—7h。 选用双锅曲毫炒干机可以完成鹿苑茶的做形作业。对茶叶含水量、做形锅温以及投叶量等关键因素进行正交试验。结果表明，三因素对主要品质成分影响较小，但对感官品质影响较大。做形温度低，投叶量大，则做形时间长，茶叶色泽黄暗。在茶叶含水量50％左右，锅温150℃，投叶量2Kg左右的条件下做形，茶叶外形条索紧结，呈“环子脚”形状，做形后期升高锅温，能得到“鱼子泡”的品质特征。 首次实现了鹿苑茶机械化加工技术。结合闷黄试验和机制工艺研究，可以确定鹿苑茶机械化加工工艺流程：鲜叶—摊放—杀青(40型连续滚筒杀青机)—毛火(40型连续滚筒杀青机)—闷黄—做形(双锅曲毫炒干机)—放泡(双锅曲毫炒干机)—干燥(名茶烘干机)—增香(名茶烘干机)。与传统手工制作工艺相比，机制工艺缩短了加工时间，降低了劳动强度，能保持鹿苑茶品质的稳定。更多还原

【Abstract】 Luyuan tea, a kind of historic famous tea of Yuanan country in Hubei province, is of yellow tea. In this article the quality formation mechanism of Luyuan tea was stated, the piling and shaping conditions were also optimized. Finally mechanizing technology was confirmed.Changes of biochemistry components and color during processing in orthodox handwork technology were investigated. Contents of tea polyphenols decreased, and that of amino acids, soluble sugar and protein increased first and then decreased. Catechins was determined by HPLC. Results showed that the EGCG and ECG contents decreased and the C and EC contents increased; chlorophyll a, chlorophyll b and total chlorophyll contents declined significantly. Chromatic evaluation method was first applied in Luyuan tea color determination. Results showed that the values of a* of drying tea and liquor were all negative and absolute values dropped during processing; the values of b* of drying tea and liquor were all positive ,b* value of drying tea decreased , but b* value of liquor increased.Results in piling experiments showed that yellow chroma increased, green chroma and luminance(L*) decreased, stewed flavor of aroma and taste sharpened with the piling temperature rising and piling duration delaying. Influence of water content, piling temperature and duration on the contents of tea polyphenols and chlorophyll was signicant, but not significant on the contents of protein , amino acids and soluble sugar. With the increase of water content, piling temperature and duration the contents of tea polyphenols and chlorophyll took on a decreased trend. According to the organoleptic tasting results and the changing trend of biochemistry components, it was regarded that the optimizing condition was: water content 40-50%, piling temperature 35 C, and piling duration 4-7h.Two-pan quhao roasting machine was applied to the shaping procedure of Luyuan tea. Orthogonal design experiment on water content, shaping temperature and duration was chosen to optimize the shaping condition. Results showed that effects of the three factors on main biochemistry components were not significant but signicant on organoleptic quality. Low shaping temperature and more leaf weight led to delaying of shaping duration and formating dull color of dry tea. In the shaping condition that water content was 40-50%, shaping temperature 150C and leaf weight about 2Kg, Luyuan tea appearance twisted tightly and ’huanzijiao’ shape appeared. At the last stage of shaping ,if pan temperature rose to 150C, ’Yuzipao’ could appear in drying tea.Luyuan tea mechanizing technology was realized first. On the results of piling and shaping experiments, the Luyuan tea mechanizing technical process could be comfirmed as follows: Fresh leaf- spreading-fixation(rotary continuous fixation machine) - firstfiring(rotary continuous fixation machine)-yellowing-shaping(two-pan quhao roasting machine) - blistering(two-pan quhao roasting machine) - drying(famous tea dryer) -improving aroma(famous tea dryer). Compared with traditional technology, mechanizing technology shortened the processing time .reduced the work intension and made the quality of Luyuan tea stable.更多还原