Release effect of aroma compounds of Keemun black tea brewed with deuterium-depleted water with different deuterium content

Keemun black tea (KBT) is one of the four famous black teas in the world. This work was the first to explore the interaction between deuterium-depleted water (DDW) and black tea. In this study, stir bar sorptive extraction (SBSE) and gas chromatography-mass spectrometry were used to determine the content of volatile substances in KBT in DDW containing deuterium (D) at a concentration of 40 parts per million (ppm), 70 ppm and the control at 150 ppm. Results indicated that there were 20 compounds (aroma activity value (OAVs) >= 1) in KBT which were identified as important substances, of which there were eight key aroma compounds (OAVs >= 10). Compared with the content and OAVs of aroma substances in natural water, water with a deuterium content of 40 ppm promoted the release of aroma substances, while the other water inhibited their release. This study is expected to provide theoretical guidance for the application of DDW among tea connoisseurs.