Up to 2009, the production tea area of Vietnam reached 128,100 hectares with the yield of 798,800 tons of fresh tea buds. However, the exported tea value of Vietname has been still of moderate level in comparision with other countries due to low quality, numerous defects and excess amount of toxic residue resulted misuse of autumn using incontrollable pesticides and chemical fertilizer as well as of polluted water supply. The common varieties of tea planted at present are Camellia sinensis var. macrophylla, Camellia sinensis var. shan, PHI, TRI 777, LDP1, lA, LDP2... The quality of the processed tea powder largely depends on the quality of fresh tea leaves, therefore this study to set up the standard for tea leaves grown in the Northern area of Vietnam in order to obtain green tea powder of high quality. Samples of fresh tea leaves collected in various seasons of the year in Thai Nguyen, Moc Chau and Phu Tho provinces. The result of analysing samples of collected fresh tea leaves showed that the tea leaves harvested in summer and autumn seasons from Moc Chau area have the highest content of water, dissoluble substances, polyphenols and tanin. Based on results obtained, the authors defined that standard for tea leaves of good quality is the buds, that have three tender leaves harvested in the early morning with natural green colour, and the water content higher 70 percent (in natural weight), dissoluble substances from 40 to 45 percent, polyphenols higher 15 percent and tanin from 20 to 24 percent (dry weight).
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