Characterization of the orchid-like aroma contributors in selected premium tea leaves.

The orchid-like odor of a tea infusion is regarded as a noble aroma and an essential sensory attribute for certain premium teas. Such tea leaves are difficult to make and the quality is not always reproducible. This study is focused on the molecular sensory basis of the orchid-like attribute in tea brews. The aroma is defined as jasmine- and magnolia-like floral notes with a fruity undertone and found to be closely related to the flower scent of the orchid Cymbidium faberi Rolfe (hui lan) by a sensory panel. Gas chromatography mass spectrometry (GC-MS) and aroma extract dilution analysis revealed that the key contributor was (Z)-methyl epijasmonate (epi-MeJA), which was also one of the main odor compounds in the flower scent of C. faberi and in the infusions of selected high-quality teas. Concentration of epi-MeJA was ranging from 0.09 to 2.2 µg/g in the oolong and green tea leaves.