Analysis of E-nose and GC-MS Combined with Chemometrics Applied to the Aroma Characteristics of High Aroma Black Tea and Traditional Congou Black Tea

To investigate the difference in aroma between high aroma black tea and traditional congou black tea, electronic nose and GC-MS were used to investigate the key factors that differentiated the aroma quality of high aroma black tea from traditional congou black tea. The results showed that the high aroma black tea had a predominantly floral aroma, while the traditional congou black tea aroma presented a sweet aroma. GC-MS detected 78 volatile substances in the two black teas, among which linalool oxide, linalool, methyl salicylate, pentanol, 2-cyclopropylethanol, (-)-carveol, β-cyclocitral, 2-ethylfuran, 1,3,8-menthatrien and 1,4-pentadiene were important aroma components to distinguish the different flavours of black tea. The total of the response values of the electronic nose detection of traditional congou black tea was significantly higher than that of high aroma black tea. The multivariate statistical analysis allowed S6 and S10 electrode signals for the identification of different flavours of black tea, and predicted that 1,4-pentadiene was an important volatile substance for the identification of different flavours of black tea. The results confirmed the aroma composition characteristics of high fragrant black tea and distinguished it from traditional congou black tea, and would provide a theoretical basis for further classification of different flavor black tea.