Abstract: Samples of one bud and two leaves from the tea variety Bixiangzao were collected in summer to prepare black tea using a modified version of the traditional processing technology by introducing piling after the first-drying process. The influence of piling was evaluated on the sensory quality, taste compounds and aroma compounds of black tea. The results showed that compared with the traditional manufacturing technology, piling for 3 h after the first-drying process could significantly improve the quality of black tea, imparting a more mellow and refreshing taste, a bright red orange color and a sweet aroma to the infusion. Moreover, the introduction of piling resulted in significantly increasing the theaflavin content in tea samples from 0.41% to 0.62% (P < 0.05), increasing the relative content of total aroma alcohol compounds from 52.25% to 57.33%, and producing new ketones with fruity aroma including 1,3,7-trimethyl-3,7-dihydro-1H-purine-2,6-dione, 4-[2,2,6-trimethyl-7-oxabicyclo[4.1.0]hept-1-yl]-3-buten-2-one and 6-methyl-5-hepten-2-one. The above results suggest that introducing piling after the first-drying process is feasible to improve the quality of black tea.

Key words: tea processing; black tea; piling; sensory quality; taste quality; aroma quality