Abstract: The effects of different pile up durations on the flavor quality of white tea were investigated based on sensory evaluation and biochemical analysis, in which the white tea with different pile-up processing durations were used as the experimental materials. The results of biochemical analysis show that with the increase of the pile-up processing duration, the flavor of the bitterness and astringency first weakened and then strengthened, the sweetness first increased and then decreased, and mellow gradually increased. In addition, and the sweet and floral increased. The contents of tea polyphenols, flavonoids, soluble sugar, catechins, free amino acids were the main reasons for the taste difference. The contents of cis-linalool oxide (furanoid), trans-linalool oxide (furanoid), α-terpineol, decanal, β-cyclocitral, geranylacetone, β-ionone and octanal were the key factors affecting the difference of aroma. Under different pile-up processing durations, piling-up for 12 d had the best flavor quality, which was conducive to increasing the contents of free amino acids, soluble sugar and catechins, while decreasing the bitter taste index, and increasing the contents of trans-linalool oxide (furanoid), decanal, β-cyclocitral, geranylacetone, β-ionone, promoted floral and sweet fragrance of white tea. Our study provided reference for the optimization of white tea pile-up process and the improvement of flavor quality of white tea.

Key words: white tea, pile-up processing duration, flavor