New insights into the effect of fermentation temperature and duration on catechins conversion and formation of tea pigments and theasinensins in black tea

Different fermentation temperature and duration combinations directly affected the type and composition of phenolic compounds. The key conditions for controlling phenolic compound conversion and fermentation direction were 60 or 90 min and 25 or 30 °C. Our study provides insights into the regulation of phenolic compound conversion during black tea fermentation.