Black tea addition enhances the aroma release of rose petals by activating related pathways during the scenting process

This study investigated the aroma-releasing mechanism of rose during the scenting process with black tea. By quantitative descriptive analysis of sensory evaluations, it was found that 20-h scenting optimized the floral fragrance accumulation while minimizing the undesirable green odors. Meanwhile, neryl alcohol, citronellol, rose oxide, geraniol, linalool, phenethyl alcohol, neryl acetate, citronellyl acetate, eugenol, methyleugenol, and phenethyl acetate were identified as the dominant contributors to the aroma profiles of rose black tea and rose petals. Notably, methylerythritol phosphate (MEP) metabolism, specifically enzymes such as 1-deoxy-D-xylulose-5-phosphate synthase (DXS), alcohol acyltransferase (AAT), and linalool synthase (LIS), and phenylalanine metabolism are the crucial pathways for the key aroma volatile synthesis. Interestingly, we found the introduction of black tea was able to early stimulate those enzymes and then activate the related metabolic pathways to facilitate the emission of rose aromatics, which were subsequently adsorbed by the tea base, yielding a floral-rich rose black tea.