Abstract: The sensory quality of six brands of strong and light aroma-type Anxi Tieguanyin tea (three batches each) was evaluated by sensory testing, and their chemical quality was analyzed by gas chromatography-mass spectrometry (GC-MS) combined with multivariate statistical analyses including principal component analysis (PCA), partial least square (PLS) and hierarchical cluster analysis (HCA). The results showed that there were differences in sensory quality among the six brands. Moisture, free amino acids and flavonoids were the key components contributing to the differences in taste among tea products. Light aroma-type tea products A and B had high contents of moisture and free amino acids, and tasted clean, fresh and mellow. The moisture content, free amino acids and flavonoids of strong aroma-type tea products C and D were in the middle and they tasted mellow and relatively thick. Strong aroma-type tea products E and F had high content of flavonoids, and tasted thick, heavy and mellow. These differences in flavor components could mainly be affected by the baking process. Indole, jasmine lactone and cis-3-hexenyl caproate were the key components that determined the aroma characteristics of different tea products. The relative contents of indole, jasmine lactone and cis-3-hexenyl caproate in light aroma-type products A and B were higher, and they had a clean and high aroma. Product A had more esters with a green odor than product B. The contents of indole and jasmine lactone in strong aroma-type products C and D were the lowest, and their aroma was relatively strong. The contents of indole, jasmine lactone and cis-3-hexenyl caproate in product D were slightly higher than those in product C, so the aroma was better. The contents of indole and jasmine lactone aroma components in strong aroma-type products E and F were in the middle, and the baking degree was slightly higher, so the aroma was strong and rich with flowery and fruity fragrance, and product F had more aldehydes which may be responsible for the fragrant aroma with fruity and flowery notes of product F. The difference in aroma components could mainly be affected by raw materials and the baking process. This study is expected to provide some theoretical basis for the fine production, quality management and flavor innovation of Anxi Tieguanyin tea products.

Key words: Anxi Tieguanyin tea products; flavor ingredients; aroma components; gas chromatography-mass spectrometry; multivariate statistical analysis