Received: 20-12-2012 / Accepted: 21-06-2013
The chemical composition of the four raw material types of Trung du tea variety has been identified (a bud and three leaves, B type, C type and the old tea leaves). The results indicate that the moisture content, soluble substance, total catechin content, cafein and total polyphenol content significantly change according to the material quality. The younger the material is, the higher the levels of these components are, and vice versa. In the researched materials, the total polyphenol content ranges from 13,23% dry matter (DM) to 21,73%DM, cafein content ranges from 2,06%DM to 4,68%DM, the total catechin content ranges from 10,80%DM to 15,93%DM. In the catechins, the relationship of the content among them are as follows: EGCG>EGC>ECG>EC>C. EGCG and ECG content increase from the old leaves to the bud and three leaves. In contract, EGC content reduce from the old leaves to the bud and three leaves.