Effect of scenting process on the taste profile of jasmine green tea and the potent bitterness-enhancing compound in jasmine flowers.

Jasmine green tea (JGT) is a widely appreciated beverage known for its delicate floral aroma thanks to scenting process, however the impact of scenting on the taste of JGT is still unclear. The present study explored how different rounds of scenting influenced the taste characteristics of JGT made with Maofeng and Tencha green tea bases. Sensory evaluation indicated that the bitterness of Maofeng was significantly intensified with increased scenting rounds, while the taste of Tencha with high levels of amino acids was barely affected. Based on the results of ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and ultra-high performance liquid chromatography-diode array detection-tandem mass spectrometry (UHPLC-DAD-MS/MS) analyses, we identified quercetin-3-O-rhamnosyl-rhamnosyl-glucoside (Q-glu-rha-rha) as a key compound in jasmine flowers contributing to the bitterness of JGTs. The spiking experiment validated the concentration and temperature-dependent role of Q-glu-rha-rha in enhancing bitterness and astringency of green tea. These findings highlight the impact of scenting rounds and green tea base selection on the sensory quality of JGT, offering valuable reference for optimizing the production of high-quality JGT.