Identification of key aroma components responsive for jasmine-like aroma in ‘Chungui’ cultivar oolong tea processing

The oolong tea produced from the Camellia sinenesis cultivar ‘Chungui’ (CG) is characterized by its distinctive and appealing jasmine-like floral aroma. However, the specific odorants contributing to this aroma and their changes during processing are not fully understood. This study investigated the changes in volatile compounds during CG oolong tea manufacturing, using the ‘Huangdan’ (HD) cultivar serving as a reference. A total of 536 volatiles were identified throughout the processing stages. Critical floral and fruity volatile compounds exhibited similar accumulation trends during the shaking and setting stages but diverged during fixing, rolling, and drying, resulting in distinct aroma attributes in the final CG and HD teas. Sensory evaluation and aroma analysis revealed that indole, ( E )-β-ocimene, ( E )-β-terpinolene, and benzeneacetaldehyde may synergistically contribute to the jasmine-like aroma of CG. These findings offer valuable insights into aroma development and changes during CG oolong tea processing, aiding in quality improvement through process optimization.