茉莉花茶窨制过程香气形成机制的研究

Formation of aroma compounds in jasmine tea during scenting process

中文关键词:  茉莉花茶  固相微萃取  香气成分  动态变化

英文关键词:jasmine tea  solid phase microextraction  aroma compounds  dynamic changes

中文摘要:

      目的 研究茉莉花茶窨制过程香气形成机制。方法 采用固相微萃取-气相色谱-质谱法测定花茶香气成分。结果 窨制茶主要香气成分为芳樟醇、乙酸苄酯、α-法呢烯、苯甲醇等。花茶窨制过程中主要香气成分随窨制时间增加的动态变化趋势可用Logistic、Sgompertz或Exponential方程进行描述。窨制结束后, 窨坯经烘焙干燥, 香气总浓度损失了约60%, 酯类和碳氢化合物损失程度约为醇类香气的4~5倍。烘焙过程中香气发生化学变化, 部分芳樟醇被氧化形成芳樟醇氧化物, 萜烯类化合物发生异构化。茶坯吸附不同香气作用方式不同, 吸附芳樟醇及其氧化物主要通过化学吸附, 吸附苯甲醇、乙酸苄酯、α-法呢烯等主要通过物理吸附。结论 本研究为优化花茶窨制工艺参数, 提高花茶品质提供参考。

英文摘要:

      Objective To study the formation of aroma compounds in jasmine tea during scenting process. Methods The aroma components were analyzed by the solid phase microextraction-gas chromatography-mass spectrometry. Results The results showed that linalool, benzyl acetate, α-farnesene and benzyl alcohol were the main aroma compounds of the jasmine tea. The dynamic trends of aroma components could be described by Logistic, Gompertz or Exponential equation. At the end of first round of scenting process, the moisture was removed from the resulted tea through the heating step, which caused 60% loss of the aroma components. Approximately 4~5 folds losses of esters or hydrocarbons compare to that of alcohols were observed. Linalool was partly oxidized to linalool oxide, and terpenes occurred isomerization during heating process. The results also indicated that the absorption of linanool and linanool oxide into tea-leaves was mainly achieved through chemical absorption, whereas absorbed benzyl alcohol, benzyl acetate, α-farnesene and so on mainly via physical absorption. Conclusion This study can provide useful information for optimizing scenting parameters to improve the quality of jasmine tea.