Abstract: This study was conducted to systematically investigate changes in sensory quality and chemical composition of Sichuan brick tea during processing. The contents of free amino acids, tea polyphenols, catechins, soluble sugar, crude fiber and protopectin (by up to 66.50%) revealed a decreasing trend during the processing of Sichuan brick tea, while opposite results were observed for the contents of water extracts, caffeine, theaflavins (TF), theabrowns (TB, by up to 194.29%) and water-soluble pectin. The sensory quality of finished Sichuan brick tea was found to be just inferior to that of steamed compressed tea sample, indicating that post-fermentation was necessary for the final transformation of tea quality. The contents of water extract, caffeine, free amino acids, tea polyphenols, catechins, TF, TR and TB in the upper stratum of pile fermentation were greatly changed, while great changes in the contents of crude fiber, protopectin and water soluble pectin were observed for the middle stratum of pile fermentation. As the pile fermentation proceeded, the upper, middle and lower strata exchanged their places to make a well-distributed fermentation finally, thus resulting in quality transformation of Sichuan brick tea.

Key words: Sichuan brick tea, processing, quality, components