<br/>Tea aroma is an important criterion for the quality of tea leaves. The aroma characteristics of various tea types are determined by their specific manufacturing process, along with the tea plant cultivar, the geographic growing location, and many other factors influencing the formation and release of aroma. In the current study, we select fresh tea leaves from the same cultivar and the same growing area and focus on the aroma formation from manufacturing processes which mimic the traditional techniques producing green, white, yellow, oolong, black, and dark teas. Aroma of tea infusions were concentrated by headspace SPME and solvent extraction, then analyzed by GC-MS. Generally, processes through oxidation assisted by tea leaf enzymes form significantly higher intensity of aroma than those with deactivation of enzymes at the beginning of process. Aroma increases with increasing oxidation degrees. In the contrary, processes of fermentation induced by microbial ectoenzymes, under conditions of higher moisture content and elevated temperature have lower overall aroma intensity while molecules generated by glycoside hydrolysis increase with prolonged fermentation time. Dimethyl sulfide, a very important aroma component in green tea, decreases with processing time regardless of the manufacturing techniques used. The aroma molecules generated under various tea process conditions from carotenoids, lipids, glycosides, and amino acids will be discussed in the presentation.

Aroma formation by tea leaf manufacturing processes

256th National Meeting (2018)

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