Abstract: A total of 74 volatile compounds were extracted and separated from 8 Anxi Tieguanyin tea samples (harvested at four different seasons; two degrees each season). The major aromatic compounds in Anxi Tieguanyin tea were nerolidol, farnesene, indole, phenylethyl alcohol, (E)-2-hexenal, nonanal, benzeneacetaldehyde, methyl linoleate, methyl linolenate, methyl palmitate, (Z)-3-hexenyl hexanoate, 3-hexen-1-ol benzoate, octanoic acid, 2-phenylethyl ester, delta- nonalactone, cis-jasmone, farnesylacetone, palmitic acid, and geranyl linalool isomer as demonstrated by principal component analysis (PCA). A PCA model for the aroma quality evaluation of Anxi Tieguanyin tea was constructed using the variance contribution rates of various eigenvalues βi (i = 1, 2, ……, k) as weight coefficients based on the comprehensive evaluation function: F = β1F1 + β2F2 +…+ βkFk and used to calculate aroma quality score for each tea sample for aroma quality evaluation. The evaluation results were in good agreement with those obtained from sensory evaluations, indicating the developed method to be feasible.

Key words: Tieguanyin tea, aroma, GC-MS, principal component analysis