基于顶空固相微萃取-气相色谱-质谱法和相对气味活性值分析不同发酵时间玫瑰花茶香气的差异

Analyzing aroma components of Rosa rugose Thunb black teas processed by different fermentation times based on headspace solid phase microextraction-gas chromatography-mass spectrometry and relative odor activity value

目的探究不同发酵时间处理对玫瑰花茶香气及感官品质的影响。方法本实验在相同环境条件下,以玫瑰花瓣为材料,采取萎凋、揉捻、发酵、干燥4道制作工艺,分发酵0 h(CK)、发酵2 h(Treat-2 h)、发酵4 h(Treat-4 h)、发酵6 h(Treat-6 h)4个处理,采取顶空固相微萃取-气相色谱-质谱法(headspace solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS)鉴定玫瑰花挥发性成分,筛选其关键呈香物质。结果共检测出938种16类挥发性代谢物。Treat-2 h、Treat-4 h、Treat-6 h与CK的挥发性代谢物存在显著差异物质554种,相对CK分别差异显著代谢物390种、416种、430种,同时对照4种处理挥发性物质的相对气味活性值(relative odor activity value,r OAV),结合感官评审结果,得出Treat-4 h为玫瑰花茶的最好处理,且发现关键呈香(玫瑰花香气)的物质为壬醇、异戊酸苯乙酯、苯乙醛、2-苯乙醇、香叶醇、大马士酮、苯甲醇、异丁酸香叶酯、(E)-6,10-二甲基-5,9-十一碳烯-2-酮、壬酸乙酯。结论玫瑰花瓣能制作成质量优异的玫瑰花茶,Treat-4 h的玫瑰花茶品质最佳。以上结果阐明了玫瑰发酵过程中香气成分变化,为实现玫瑰花产业资源化利用提供了参考依据。

Objective To investigate the effects of different fermentation times on the aroma and sensory quality of Rosa rugose Thunb tea.Methods In this experiment,under the same environmental conditions,four production processes of withering,kneading,fermentation and drying were adopted for 4 treatments,namely CK,Treat-2 h,Treat-4 h and Treat-6 h,and headspace solid phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS)was adopted to characterize the volatile constituents of Rosa rugose Thunb tea and to screen the main aroma-presenting substances.Results A total of 938 volatile metabolites of 16 types were detected.There were 554 kinds of volatile metabolites with significant differences between Treat-2 h,Treat-4 h,Treat-2 h and CK,All in 390,416,and 430 kinds of metabolites with significant differences relative to CK,respectively,and simultaneously comparing the relative odor activity values(rOAV)of volatile substances in four different treatments,combined with sensory evaluation results,it was concluded that Treat-4 h was the best treatment for rose tea.The key Rosa rugose Thunb aroma substances were found which were nonanol,phenethyl isovalerate,phenylacetaldehyde,2-phenylethanol,geraniol,damascenone,benzyl alcohol,geranyl isobutyrate,(E)-6,10-dimethyl-5,9-undecadien-2-one,ethyl nonanoate.Conclusion Rosa rugose Thunb can make excellent quality Rosa rugose Thunb tea,and the best quality of Rosa rugose Thunb tea is obtained from Treat-4 h in the conventional fermentation process.The above results elucidate the changes of aroma composition during Rosa rugose Thunb fermentation and provide a reference basis for realizing the resource utilization of Rosa rugose Thunb industry.