【作者】 徐准盾；

【导师】 龚淑英；

【作者基本信息】 浙江大学 ， 茶学， 2006， 硕士

【摘要】 本研究是利用韩国生产的绿茶原料,选取了十八个有代表性的茶样,对不同产地、不同加工方法及不同生产时期的茶叶的主要呈味物质进行分析研究,并用不同温度、时间和茶水比进行冲泡处理,对茶汤中的茶多酚、氨基酸和咖啡碱三个主要绿茶品质的化学成分含量,浸出浓度与比率进行测定,就温度、时间、茶水比等一些因素对茶汤内质成分及感官品质的影响进行了研究,同时在中国绿茶审评方法和生化成分分析比较的基础上,寻找韩国绿茶审评方法的理论依据。 分析三个产地的茶样,茶多酚、氨基酸的含量存在显著差异,且达显著水平。加工方法对茶多酚含量的影响是手制釜炒茶和机械釜炒茶间差异不显著,其他加工方法间存在着显著差异;加工方法对氨基酸的含量有一定的影响,四种不同加工方法所加工的茶的氨基酸含量有显著差异。不同加工方法的茶样感官审评的结果是,机械釜炒茶的各项因子得分都最高,手制釜炒茶的得分普遍都较低。可以看出目前韩国手工制茶的水平不高,机械制茶的技术要高于手工制茶的水平。从测定不同生长成熟度(嫩度)茶样的主要呈味物质的总含量的结果可以看出,茶多酚、氨基酸、咖啡碱与水浸出物的含量的变化趋势一致,呈现先较低后升高再降低的变化规律。 温度对茶汤中茶多酚、氨基酸、咖啡碱和水浸出物的浸出浓度的影响是随着水温的升高浸出浓度也增加。在不同冲泡时间处理下,对茶汤中茶多酚、氨基酸、咖啡碱总量分析,得出茶汤中茶多酚和咖啡碱的浸出浓度总的趋势是随时间的延长而逐渐增加;氨基酸则是随时间的延长而不断增加,但时间越长,增加的幅度越小。温度和不同冲泡时间处理,对绿茶茶汤中各品质成分均有极显著差异。 不同茶水比韩国绿茶的主要品质的影响是用水量增大,茶多酚、氨基酸、咖啡碱、水浸出物的浸出浓度均逐渐减少。用水量在100ml时,绿茶茶汤中主要品更多还原

【Abstract】 In this research, we selected 18 representative Korean green tea products, which are different in the producing area, the processing methods and producing time, to analyse their quality related main components. We also utilize different treatments, including the different tea pouring temperature, time and tea-water proportion treatment, to compare the chemical composition contents like tea polyphenol, amino acids and caffeine in green tea. Results show that the factors of temperature, time and the tea-water proportion could do effects both on the composition of tea soup and on the sensory tea quality. Furthermore, on the basis of Chinese founded tea quality judgment methods and biochemical analytical methods, we are trying to find out the principle and theories for quality judgments of Korean green tea.By analysis of tea samples from three different producing areas, we find that there is significant difference in the contents of tea polyphenols and amino acids. From the sensory evaluation of samples by different processing methods, results show that all the mechanically produced fired green tea run up a score obviously higher than the fired green tea handmade, which imply that nowadays the hand-make producing is limited in Korea, while mechanical production of fired green tea has reached a relatively more high lever. By detecting of different tenderness of tea samples, we find that the regular changed tendencies for the contents of tea polyphenols, amino acids, caffeine and total extracts are unanimous, that is, all these contents are low in the tender leaves and increase as the growth of maturity, but then decrease in the hard mulberry leaves.The Water temperature for tea soup is important in effecting the concentration of tea extracts, concluding tea polyphenol, amino acids, caffeine and total extracts. Itshows that all the amounts of tea extract increase as well as the water temperature goes up. After treated with different temperature, we analyze the tea polyphenol, amino acids and caffeine in tea soup, and find that the final concentrations of tea polyphenol and caffeine increase with prolonged pouring time. It’s also increased for the amino acids, but such a trend would slow down with prolonged pouring time. From the current research, both the water temperature and pouring time could affect the tea quality significantly.The tea-water proportion could also affect the concentrations of tea polyphenols, amino acids, caffeine and total extracts in tea soup. It shows that their concentration decrease gradually with increased water capacity, respectively, and it reaches a peak for extracts concentration when using 100 ml water. Meanwhile, the tenderness has relative effects on the quality of green tea soup. It shows that along with the maturation of green tea, the concentration of all components in the soup reduced, and there is a significant relationship between the tenderness and green tea quality.Green teas with different processing methods, which are treated with different water temperature and pouring time, could affect the components in tea soup significantly. With the water temperature goes up, the tea polyphenols, amino acids, caffeine and total extracts increase accordingly. With the pouring time prolonged, those components increased more significantly in the tea soup. Under both the treatment of different temperature and time, there is significant relationship among green teas from different producing area in Korea.When the samples are poured by using 100°C hot water for 4 min, we analyze five different tea-water proportion treatments to search their highest appraisements. Results show that the aroma is best with the ratio of 3:200, the soup color is best with the ratioof 3:250, and the taste is best also with the ratio of 3:200. When the samples are poured by using 100°C hot water for 5 min, the concentrations of tea polyphenols, amino acids and caffeine are the highest and the C/N is the least at the ratio of 3:100 in all the treatments.We conclude from the comparison of different methods as that: There is not obvious difference in the accuracy rates for the sensory evaluation of experienced evaluators, but a discrepancy for that of unexperienced evaluators. Nevertheless, the method for green tea appraising by prepared with 100°C hot water for 4 min at the ratio of 3g: 200ml is obviously better than that prepared with 100°C hot water for 5 min at the ratio of 3g: 150ml.In conclusion, we bring forward a relatively reasonable appraising method for Korean green tea, that is, using 3 grams dry Korean green tea to prepare with 200 ml 100°C hot water for 4 min.更多还原