Composition Profile
Verified · 2026-09-26- 01Changes in major quality compounds during manufactureAfter fresh leaves were processed into Ya'an Tibetan Tea, catechins, tea polyphenols, free amino acids, caffeine and soluble sugars decreased by 69.88%, 46.39%, 68.53%, 25.85% and 7.11% respectively. Thearubigins, theaflavins and theabrownins increased to 24.33, 53 and 5.67 times their fresh-leaf levels respectively.Other sample
- 02TheabrowninsAs storage time increased from 4 to 10 years, theabrownins rose from 5.95 g/100 g to 8.54 g/100 g.Dry-leaf sample
- 03Total polyphenolsAcross 4–10 years of storage, total polyphenols declined significantly; total flavonoids, caffeine, total catechins and multiple catechin monomers also declined significantly.Dry-leaf sample
From fresh leaf to finished tea, catechins, tea polyphenols, free amino acids and caffeine decrease substantially while the tea-pigment system changes dramatically. During further storage, theabrownins rise while polyphenols, flavonoids, caffeine and catechins generally decline.

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