Abstract: The solid phase microextraction (SPME) conditions for the analysis of flavor compounds in Lichuan Hong tea by gas chromatography-mass spectrometry (GC-MS) were optimized using response surface methodology (RSM). The composition of flavor compounds in Lichuan Hong tea was compared with that in Yihong and Dianhong tea. The results showed that the optimal extraction conditions were as follows: solid-to-liquid ratio 1:4.11 (g/mL), extraction time 50.15 min, and extraction temperature, 71.75 ℃. Under these conditions, a total of 73 flavor substances were identified in Lichuan Hong tea, mainly including furans, aldehydes, alkanes and esters, accounting for 21.202%, 20.11%, 13.751% and 11.662% of the total amount, respectively. A total of 59 flavor components were identified in Yihong tea, including furan, alcohol, aldehyde and alkane, accounting for 23.445%, 21.04%, 19.816% and 18.070% of the total amount, respectively. A total of 66 flavor components were identified in Dianhong tea, including alcohol, aldehydes and furans, accounting for 35.587%, 15.103% and 12.229% of the total amount, respectively. Partial least squares-discriminant analysis (PLS-DA) was performed on all flavor substances and nine selected flavor substances in the three black teas. The flavor types of black tea could be predicted based on the selected flavor substances, and even the prediction ability was better than that based on all flavor substances. In addition, variable importance in projection (VIP) analysis indicated that linalool, cis-linalool oxide, geraniol and 2-hexenaldehyde had the greatest influence on the flavor of the three black teas, and that these flavor components could be used as the main characteristic markers for distinguishing the three black teas. The results of this study enrich the basic theory of the flavor quality of Lichuan Hong tea and provide the basis for aroma quality control of Lichuan Hong tea.

Key words: partial least squares-discriminant analysis; solid phase microextraction; gas chromatography-mass spectrometry; Lichuan Hong tea; Yihong tea; Dianhong tea