Abstract:

Souchong and congou made with the same class of fresh tea leaves obtained from the same tea variety were
compared and analyzed for their quality characteristics in terms of the main biochemical components, physical characteristics
of tea infusion and volatile compounds. The results indicated that the content of tea polyphenols was significantly higher in
souchong while the contents of caffeine, theaflavins and thearubigins were significantly higher in congou. There were no
significant differences in the contents of soluble sugar, soluble protein and free amino acids between souchong and congou.
The color parameters a* and b* and precipitate amount were significantly higher in congou at 8.38, 39.19 and 246.78 mg/L,
respectively, while L* value and transmittance were significantly higher in souchong at 29.16 and 76.53%, indicating that
congou possessed a yellower and redder infusion while souchong had a more transparent one. The odor activity values (OAVs)
of samples were examined and calculated. There were 11 and 13 kinds of aroma components, respectively, in souchong and
congou whose OAVs reached over 1. The main aroma substances were β-ionone, methyl benzoate and linalool in souchong,
which can exhibit significant sweet aroma and β-damascenone, β-ionone, methyl benzoate and hexanal in congou showing
flowery flavor. β-Damascenone and hexanal were probably the effective aroma components to differentiate the aroma type of
congou from souchong given that they particularly existed in congou and both had high OAVs reaching over 1.

Key words: souchong, congou, quality characteristics, odor activity values (OAVs)