Abstract: In order to investigate the optimum baking temperature for granular shaped oolong tea processing, final firing tea was used to bake at 120℃, 100℃and 80℃, respectively. By sensory evaluation, we found that the score of Jiulongpao Oolong teas with 80℃baking temperatures were higer than other Jiulongpao oolong teas. The quality of Jiulongpao Oolong tea baked with 80℃ temperature was the best. Chemical analysis indicated that the contents of the major biochemical components of oolong tea, such as tea polyphenols, the water extract and the amino acid decreased with the increase of baking temperature, but the contents of caffeine, the total catechins and the flavonoid constituents revealed no significant differences. The contents of L-Theanine, Aspartic aicd, Serine, Glutamic acid were decreased while the content of EGC and C were increased with the raise of baking temperature. The aroma constituents of Jiulongpao Oolong tea with different baking temperature treatment were determined by HS-SPME/GC-MS.The content of alcohols, esters, ketones and nitrogenous compounds were decreased but the alkane and the vinyl compounds were increased. Concentration of aromatic constituents with aroma of flowers such as linalool, linalool oxides, nerolidol, hexanoic acid, 3-hexenyl ester, (Z)-butanoic acid, 2-methyl-, hexyl ester, β-phenylethyl butyrate, benzoic acid, hexyl ester, methyl jasmonate, hexanoic acid, hexyl ester, α-Jonone, 5,9-Undecadien-2-one,6,10-dimethyl-, cis-Jasmone, indole decreased. The Hydrocarbon compounds such as β-Myrcene, Limonene, 5-Methylenecycloocta- 1,3-diene, β-sesquiphellandrene, 2,4,6-Trimethyl-1,3,6-heptatriene, dodecane and the nitrogenous compounds such as benzyl nitrile increased distinctively.

Key words: Jiulongpao, Oolong tea, baking, biochemical components, quality