The flavor characteristics and antioxidant capability of aged Jinhua white tea and the mechanisms of its dynamic evolution during long-term aging

This study explored the sensory characteristics, metabolites and antioxidant capability of aged Jinhua white tea (AJWT) over different years of aging and revealed the transformation mechanism of these characteristics during the long-term aging process. The flavor wheel of AJWT was constructed, and its unique flavor was dominated by mellowness, smoothness, a fungus fragrance, and a stale flavor. The high content of theabrownine, soluble sugar, flavonoids and 25 aroma components made important contributions to the formation of the unique flavor of the AJWT, and their content significantly increased during the long-term aging process of 5–10 years. This was related to the microbial bioconversion, the oxidative degradation of catechins, the hydrolysis of flavonosides and the decomposition of polysaccharides. Contrary to folk experience, AJWT had weak comprehensive antioxidant capacity, mainly due to its low content of tea polyphenols, catechin components and caffeine, which decreased significantly during the long-term aging of 5–10 years.