Scenting tea with Jasminum sambac is beneficial to forming a unique taste of jasmine tea, which is regulated by numerous compounds. To investigate the relationship between metabolites in jasmine and jasmine tea, as well as the impact of metabolites on the characteristic taste of jasmine tea, the liquid chromatography-mass spectrometry, sensory evaluation, and multivariate analysis were applied in this study. A total of 585 and 589 compounds were identified in jasmine tea and jasmine, respectively. After scented, jasmine tea added 70 compounds, which were believed to come from jasmine flowers. Furthermore, seventy-four compounds were identified as key characteristic compounds of jasmine tea, and twenty-two key differential metabolite compounds were believed to be used to distinguish jasmine tea scented differently and contribute to the taste of jasmine tea. Additionally, the relationship between taste compounds and aroma quality was also explored, and it was found that five compounds were positively correlated with the aroma properties of jasmine tea and seven compounds were negatively correlated with the aroma properties of jasmine tea. Overall, these findings provided insights into the future study of the mechanism of taste formation in jasmine tea and provided the theoretical basis for the production of jasmine tea.

“Golden flower” fungi in dark tea are beneficial to human health. The rapid identification method of “golden flower” fungi can verify the quality of dark tea products and ensure food safety. In this study, 6 strains were isolated from Liupao tea. They were respectively identified as A. cristatus, A. chevalieri, and A. pseudoglaucus. A. pseudoglaucus was reported as Liupao tea “golden flower” fungus for the first time. It was found that the ITS and BenA sequences of A. cristatus and A. chevalieri were highly conserved. It is difficult to clearly distinguish these closely related species by ITS sequencing. To rapidly identify species, multiplex PCR species-specific primers were designed based on orphan genes screened by comparative genomics analysis. Multiplex PCR results showed that orphan genes were specific and effective for the identification of A. cristatus and A. chevalieri isolated from Liupao tea and Fu brick tea. We confirmed that orphan genes can be used for identification of closely related Aspergillus species. Validation showed that the method is convenient, rapid, robust, sequencing-free, and economical. This promising method will be greatly beneficial to the dark tea processing industry and consumers.

• Tea infusion was suitable to be extracted for 5 min with 1:25 tea/water ratio. • Two hundred and four volatiles were identified in jasmine tea infusion. • Twenty-five key volatile compounds of jasmine tea infusion were identified. • Most key volatile compounds were positively correlated with amount of flowers. • Jasmine tea that were scented with 80 % flower is good for quality and cost.

• 13 compounds is believed to be the characteristic taste compounds of scented broken tea. • The scenting process helps to improve the taste of broken tea. • The optimal scenting time for jasmine tea is 10 h. • The involved mechanism of taste improvement was explored.

In this study, the aroma characteristics of jasmine tea (JT) scented by three kinds of multipetal jasmine, Xiangfei 2, 4 and 11 were investigated with common double-petal jasmine as control. Compared with the strong floral aroma of double-petal jasmine tea (TS), the JT scented with Xiangfei 2 (TC) showed fresher aroma, the JT scented with Xiangfei 11 (TB) exhibited sweeter aroma, while the overall aroma of JT scented by Xiangfei 4 (TA) was overall lower. Among them, Benzoic acid, 2-hydroxyl-, ethyl ester contributed to TB's sweet note, 3-Hexen-1-ol, benzoate, (Z) - and Methyl salicylate were related to the fresh aroma of TC, Linalool, Methyl anthranilate, 4-Hexen-1-ol, acetate and Benzyl alcohol were linked to TS's floral aroma. Molecular docking identified hydrogen bonding and hydrophobic interactions as key drivers for aroma compounds binding to olfactory receptors, and molecular dynamics simulations (MDs) validated the stability of these interactions. This study provides a theoretical basis for the application of multipetal jasmine in JT processing.