Aroma formation in jasmine tea: insights from metabolomics and microbial community analyses during multiple scenting processes

Jasmine tea is a classical example of flower-flavoured tea, produced by scenting tea leaves with jasmine flowers. Sensory evaluation, untargeted metabolomics, and ITS and 16S rRNA sequencing mapped the landscape of volatile compounds and microbial profiles of jasmine tea during scenting processes (zero, three, six times). Aroma evaluation showed that fragrance, floral, freshness, and persistence levels continuously increased with successive scenting processes. An aroma wheel was constructed based on differential volatile compounds, with floral, fruity, and green aromas dominating. Six key aroma compounds were identified through odor activity value (OAV), including ethyl 2-methylbutyrate (0, 19584.24, 21660.09), (Z)-hex-3-enyl acetate (282.95, 477.89, 473.38), 1-Hexanol (0, 5.55, 5.66), 6-Methyl-5-hepten-2-one (0, 46.10, 46.17), Benzyl alcohol (0.68, 1.12, 1.16), and Indole (6.36, 10.95, 11.46), which were identified as the primary aroma contributors. Significant microbial community shifts were observed, with a core functional microbiota consisting of nine bacteria genera ( Pelomonas , Bacillus , Stenotrophomonas , Staphylococcus , Sphingomonas , Pseudomonas , Microbacterium , Aureimonas , and Bosea ) and four fungi taxa ( Wallemia , Uwebraunia , Alternaria , and Penicillium ) showing significant correlations with aroma compounds. This study provides valuable insights into the key aroma compounds and core microorganisms involved in scenting process of jasmine tea.