Comparative analysis of aroma compositions in different-grades Yunnan Congou black tea

[Objective]Major aroma compositions of different-grades Yunnan Congou black tea were comparatively analyzed and their quality was assayed in order to provide guidance for enhancing Congou black tea production.[Method]Aroma substance was enriched using same distillation extract method and aroma compositions were analyzed using SDE/GC-MS in different-grades Yunnan Congou black tea samples comparatively.[Result]The results showed that different-grade Yunnan Congou black tea had nearly the same aroma compositions,but their contents varied a lot.The linalool,linalool oxide,α-Terpineol and geraniol contents were higher in superior Yunnan Congou black tea compared to those presenting in inferior one.However,inferior Yunnan black tea had higher leafaldehyde,benzaldehyde and benzeneacetaldehyde content.[Conclusion] Higher-graded Yunnan Congou black tea had good fragrance quality and all different-graded Congou black teas presented strong fragrance,and high aroma and strong taste characteristics of Diangong time tea.