基于感官组学分析玉米香型南川大茶树工夫红茶特征香气

南川茶是重庆市南川区特有的古茶树资源,具有较高的开发利用价值。采用顶空固相微萃取结合气相色谱-质谱联用技术（HS-SPME-GC/MS）、气相色谱-嗅闻分析技术（GC-O）以及通过计算香气活度值（OAV）与香气特征影响值（ACI）,对南川大茶树鲜叶制成的玉米香型工夫红茶香气特征进行分析。结果表明,玉米香型工夫红茶中OAV>1的挥发性化合物有22种,其中二甲基硫的OAV最高（1 187.32）,其ACI达51.56%,远高于其他化合物。GC-O嗅闻到26种活性香气化合物,其中二甲基硫的嗅闻强度较高（4.75）,并呈现出玉米香属性。香气重组与删除试验进一步验证了二甲基硫对于玉米香型工夫红茶的重要性。本研究明确了玉米香型南川大茶树工夫红茶的特征香气成分,为南川大茶树工夫红茶品质的定向调控提供一定理论依据。

Characterization of the Key Aroma in Corn-scented Congou Black Tea Manufactured from Camellia nanchuanica by Sensory Omics Techniques

Camellia nanchuanica is endemic to Nanchuan district, Chongqing and has a high development value. In this study, the characteristic aroma of corn-scented Congou black tea from Camellia nanchuanica was analyzed by headspace-solid phase microextraction, gas chromatography-mass spectrometry (HS-SPME-GC/MS), gas chromatography-olfactometry (GC-O), odor activity value (OAV) and aroma character impact value (ACI). The results show that 22 key aroma compounds with OAVs≥1 were identified in the corn-scented black tea. Dimethyl sulfide had the highest OAV (1 187.32), and its ACI was 51.56%. A total of 26 odor-active compounds were perceived by GC-O. Dimethyl sulfide had a higher olfactory intensity, which had a “corn-like” odor. The results obtained by the OAV approaches and by GC-O method for key aroma identification were in good agreement. The importance of dimethyl sulfide in corn-scented black tea was verified by aroma recombination and omission test. Focusing on the analysis of the active aromas of corn-scented black tea would provide a theoretical basis for the quality control of this prized tea.