Abstract: The amount and density of tea hairs on made tea is an important indication to assess tea quality. To determine the chemical compositions of tea hairs, four tea samples rich in tea hairs, namely, Biluochun, Yunnan black tea, Baihao Yinzhen and Baimudan were used. Tea hairs was compared to the non-pubescent leaves. The contents of C, N and C/N, the composition and contents of amino acids, primary mineral elements were analyzed by elemental analyzer, automatic amino acid analyzer and ICP-OES respectively. The C and N contents in tea hairs ranged from 2.96% to 4.74% and 42.87% to 45.58%, respectively. The N contents in tea hairs were significantly lower than those in the non-pubescent leaf (P<0.01), while C/N showed an opposite trend and C contents showed no significant difference. Hydrolytic amino acids and free amino acid contents in tea hairs ranged from 10.78 % to 12.46% and 20.78βmg·g^-1 to 34.65βmg·g^-1, respectively. The major constituents and the total amount of hydrolytic amino acids and free amino acids in tea hairs were all significantly lower than those in tea body (P<0.05), with an exception of the ratio of theanine to total free amino acids (P<0.05). While the differences of the free amino acid constituents (theanine, asparagine, glycine, and γ-GABA) were not significant. The mineral elements in hairs were generally slightly lower than those in tea. Among them, the P and S contents showed the largest differences (P<0.01). In summary, the contents of amino acids and mineral elements in tea hairs are not higher than those in tea body, but the composition differences in quality constituents might contribute to the special quality characteristics.

Key words: tea hairs, C/N, amino acid, mineral element