Revealing the differences in aroma of black tea under different drying methods based on GC–MS, GC-O
Mingxia Lu, Caiyan Sheng, Ke Han, Tiehan Li, Qiuyan Liu, Jixin Zhang, Luqing Li, Yujie Wang, Jingming Ning
Abstract
Drying greatly affects the aroma of black tea. In this study, the differences in aroma of black tea under hot-air drying (HD), sun drying (SD), and pan-fired drying (PD) were investigated through quantitative descriptive analysis. Headspace solid-phase microextraction and solvent assisted flavor evaporation combined with gas chromatography–mass spectrometry and gas chromatography-olfactory were used to analyze the overall aroma profile of black tea. Aroma extract dilution analysis and odor activity values revealed that 15 aroma-active compounds led to differences in aroma, namely linalool, geraniol, phenylethyl alcohol, phenylacetaldehyde, ( Z ) -linalool oxide (furanoid), β -damascenone, dimethyl sulfide, methional, 2-methylbutanal, 3-methylbutanal, methyl salicylate, β -myrcene, hexanal, 1-octen-3-ol, and heptanal. Among them, geraniol, linalool, and methional significantly enhanced the floral and roasty aroma of HD, while hexanal enhanced the green aroma of SD. Finally, our results were validated through aroma recombination and addition experiments. This study provides a theoretical basis for improving the aroma of black tea. • The effects of drying methods on aroma of black tea were studied. • 15 aroma-active compounds caused differences in aroma. • Geraniol, β -damascenone and ( E ) - β -ionone were the most active aromas in black tea. • Hot-air drying significantly enhanced the floral and roasty aroma of black tea.