A win-win strategy between carbon reduction and flavor enhancement: Optimized rolling process for large-leaf yellow tea with fresh and flowery aroma.

Conventional large-leaf yellow tea (LYT), made from mature leaves, relies on energy-intensive old-fire roasting to mitigate coarse flavor, thereby posing significant sustainability challenges. This study established a novel "heavy rolling - light roasting" cascaded improvement strategy to LYT, achieving the balance between quality enhancement and energy efficiency. Sensory evaluation combined with chemical analyses revealed that the coarse and green odor was reduced while fresh and flowery aroma was imparted to LYT. Linalool, geraniol and nonanal et al. were identified as key volatile compounds to the novel aroma profile. Tissue-specific aroma contributions were further elucidated, with buds, leaves and stems respectively exhibiting flowery, fresh, and coarse-sweet characteristics, and leaves were identified as the key contributors. Carbon footprint assessment confirmed that the cascaded processing technology for LYT significantly reduced carbon dioxide (CO2) emissions. These findings provided a practical pathway for high-quality and low-carbon tea productions, promoting sustainable development in tea industry.