Effect of shaking manners on floral aroma quality and identification of key floral-aroma-active compounds in Hunan black tea.

[Display omitted] • Shaking in the early withering stage is a key process effecting the floral aroma of Hunan black tea. • Volatile compounds of dry tea, tea infusion and infused leaf of Hunan black tea were systematically analyzed. • A total of 81 differentially volatile compounds were identified in Hunan black teas. • Indole and methyl jasmonate were identified as key floral aroma compounds in Shaking Hunan black tea. Shaking is a key process effecting the floral aroma of Hunan black tea (HBT). In this study, the aroma composition of HBTs shaken in the early withering stage (ES1, ES1 + LS1, and ES2), shaken in the late withering stage (LS1), and not shaken (NS), and the identification of main floral aroma compounds were analyzed using sensory evaluation combined with gas chromatography-mass spectrometry (GC–MS), gas chromatography–olfactometry (GC-O), and aroma recombination experiments. Sensory evaluation results showed that the floral aroma of HBT shaken in the early withering stage was with high intensity, whereas HBT shaken in the late withering stage had low-intensity floral aroma. GC–MS identified a total number of 81 differential volatile compounds in HBT, including 30 esters, 18 aldehydes, 15 alcohols, 12 terpenes, 4 ketones, and 2 nitrogen-containing compounds. Further screening of important floral aroma differential compounds was performed using sensory-guided, odor activity value (OAV), and GC-O analysis, which identified three critical floral aroma differential compounds. Eventually, absolute quantification analysis and aroma recombination experiments confirmed that indole and methyl jasmonate were the most critical compounds of HBT determining floral aroma intensity. The findings of this study provide valuable guidance for the production of HBT with rich floral aroma attributes. [ABSTRACT FROM AUTHOR]