Quality Characteristics of Stale Flavor Liupao Teas and Establishment for Evaluation Method of Aroma Quality

In order to explore the quality characteristics of stale flavor liupao teas,the quality components of typical samples were analyzed and the aroma constituents were determined by HS-SPME/GC-MS. PCA was carried out on 26 common aromatic substances and constructed an aroma quality comprehensive evaluation function for stale flavor liupao teas with the principal component linear regression equation by using the variance contribution rates of various eigenvalues as weight coefficients. Moreover,established function was used to calculate the rank of sample scores for aroma quality evaluation. The results showed that the main quality components of stale flavor liupao tea were as follows:tea polyphenol content 13.05%±2.14%,amino acid content 1.80%±0.13%,caffeine content 4.44%±0.36%,water extract content 38.00%±2.81%. The characteristic aromatic compounds of "stale flavor" were α-cedrol,β-linalool,dihydro actinidiolide,α-terpineol and β-Ionone. Compared the results of sensory and functional evaluation F=52.962F1＋20.825F2＋15.348F3＋7.592F4,the evaluation results of aroma by two methods were basically similar and this indicated that it was feasible to use the comprehensive evaluation function to evaluate the aroma quality of liupao teas.