甜菊干叶及其茶制品中挥发性成分的比较分析

Comparative Analysis of Volatile Components in Stevia Dry Leaves and its Tea Products

摘要:

为考察普通甜菊干叶与按绿茶加工方式加工的甜菊茶制品香气成分，采用顶空固相微萃取-气相色谱质谱联用法，结合计算机检索对挥发性成分进行鉴定与分析。结果表明：普通甜菊干叶检出76种挥发性物质，而按绿茶加工方式得到的甜菊茶制品检出73种挥发性成分。其中共有的香气成分有β-榄香烯、α-香柠檬烯、(E)-β-金合欢烯、α-葎草烯、反式-橙花叔醇等，但各自的相对含量差别较大；另外，甜菊茶制品与甜菊干叶具有自己独特的香气成分，甜菊干叶的特有香气成分主要有石竹烯、甘香烯等。甜菊茶制品的特有香气成分主要有柏木烯醇、二氢猕猴桃内酯、(-)-异丁香烯等挥发性成分。甜菊茶制品与甜菊干叶挥发性成分相比，烯烃类化合物的种类及含量有所减少，而醛类、脂类、醇类化合物类有所增加，说明快速热加工对甜菊叶具有增香去异味的作用。

Abstract:

The composition of aroma compounds in dried Stevia leaf and tea products were analyzed by headspace solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) combining with computer search. The results showed that 76 and 73 volatile compounds existed in stevia leaves and tea products respectively. β-Elemene,α-bergapten, (E)-β-farnesene,α-Humulene and Trans nerolidol were identified in both two kinds of dry leaves, but their relative contents were considerable different in the two kinds of samples. In addition, caryophyllene and elixene were the characteristic compounds in stevia dry leaves. Cedrenol, dihydroactinidiolide and (-)-isocaryophyllene were found in stevia tea products. Compared with volatile components of dry leaves in stevia, the types and contents of olefins compounds decreased, while aldehyde compounds, lipids, alcohol compounds increased in its tea product, indicating that rapid heating could enhance the aroma component contents.