Comparative Research On Quality Of China And Korea Green Teas (Camellia Sinensis (L.) O. Kuntze)

Korean tea and tea processing technique were introduced from China and the later was reformed according to Korean tea consuming customs. In the present study, samples of Korean and Chinese roasted green teas were collected from tea markets and their qualities were investigated by sensory quality evaluation, chemical and color difference analysis. The results were as follows:1 The sensory evaluation showed that average quality score of Korean roasted tea was 86.37±3.97, 1% over the Chinese one 85.59±2.88. Results of quality attribute analysis showed that there was no significant difference in infusion color between Chinese and Korean roasted green teas. However, the scores of aroma and taste of Korean green tea was higher than Chinese green tea. Obvious differences in sensory quality of green teas from various estates were observed. Sensory quality of green tea produced in Jizhou showed the best, followed by those in Baocheng and Hedong. The total score of Jizhou green tea was 5.2% over that of the Hedong.2 Analysis of moisture content, water-soluble solids and major chemical compositions showed that Korean roasted green tea had less contents of moisture and caffeine, but higher content of amino acids and water-soluble solids than Chinese green tea. Total concentrations of tea polyphenols of Korean and Chinese green teas were not statistically different. The higher concentrations of amino acids and water-soluble solids might be responsible for the higher raking of sensory quality of Korean tea and the lower moisture content of Korean tea might be good for its quality preservation. The high concentration of amino acids in Korean green tea might be related to its higher latitude where the tea was grown.3 Color difference of tea liquors showed that there were significant differences in lightness, greenness and yellowness in liquor color between Chinese and Korean green teas. The liquor color of Korean roasted green tea had higher lightness and lighter yellowness. Chinese green tea gad a deeper hue, resulting in darker liquor, which might be related to its higher moisture content and partial oxidation of tea polyphenols duringstorage and marketing.According to the above results, it is considered that there were two reasons responsible for the characteristics of Korean green tea qualities. First, The Korean tea plant was grown in estates of higher latitude in which the temperature difference was bigger that was favorable for the accumulation of amino acids in tea. Second, fresh green leaf was usually fixed by steam for Korean tea, instead of pan-fixation for Chinese tea because the tea polyphenol oxidase was inactivated more quickly by steam vapor than pan heating. The lower moisture content was also favorable for quality preservation of Korean green tea. The author considered that the improvement of processing and storage will be good for the exporting of Chinese green tea to Korea. The Korean tea culture and its relationship with Chinese tea culture were also reviewed in the present paper.