普洱大叶种红茶和熟茶中20种挥发性组分对比研究

Comparison research of 20 volatile components in Pu’er large leaf species black tea and ripe tea

目的比较分析普洱大叶种红茶和熟茶的挥发性组分。方法采用水蒸气蒸馏法提取普洱大叶种红茶和熟茶的挥发性组分,气相色谱-质谱仪(gas chromatography-mass spectrometry,GC/MS)测定,结合组分香气阈值和气味活度值讨论各组分在茶叶呈香中的贡献。结果 20种挥发性组分中,红茶中呋喃型氧化芳樟醇、芳樟醇、苯乙醇、α-松油醇、香叶醇和棕榈酸甲酯的含量为熟茶的4~72倍,而熟茶中1,2,3-三甲氧基苯、1,2,4-三甲氧基苯、顺式茉莉酮和二氢猕猴桃内酯的含量为红茶的16~610倍。呋喃型氧化芳樟醇两种异构体含量在红茶和熟茶中优势构型表现出一致性,而橙花叔醇2种异构体含量在红茶和熟茶中优势构型表现出不一致性。结论从20种挥发性组分在熟茶和红茶中的气味活度值角度对比,苯甲醛、呋喃型氧化芳樟醇、芳樟醇、β-环柠檬醛、1,2,3-三甲氧基苯、1,2,4-三甲氧基苯、α-紫罗兰酮、β-紫罗兰酮和棕榈酸甲酯9个挥发性组分在红茶和熟茶呈香均有实际的贡献,其中呋喃型氧化芳樟醇、芳樟醇和棕榈酸甲酯在红茶中呈香贡献远高于熟茶,而1,2,3-三甲氧基苯,1,2,4-三甲氧基苯在熟茶中的呈香贡献远高于红茶。

Objective To compare and analyze the volatile components of Pu’er large leaf species black tea and ripe tea.Methods The volatile compounds of Pu’er large leaf black tea and ripe tea were extracted by steam distillation and analyzed by gas chromatography-mass spectrometry(GC-MS).The contribution of each component to the aroma of tea was discussed by combining the aroma threshold and odor activity value of the components.Results Among the 20 volatile components,the contents of furan type oxidized linalool,linalool,phenethyl alcohol,alpha-terpineol,geraniol and methyl palmitate in black tea were 4-72 times of that in ripe tea’s,while the contents of 1,2,3-trimethoxybenzene,1,2,4-trimethoxybenzene,cis-jasmone and dihydroactinidiolide in ripe tea were16-610 times as many as black tea’s.The content of 2 linalool oxide isomers showed dominant configurations consistency in black tea and ripe tea,while two nerolidol isomers exhibited inconsistency in black tea and ripe tea.Conclusion From the perspective of the odor activity values of 20 volatile components in ripe tea and black tea,the9 volatile components of benzaldehyde,furan type oxidized linalool,linalool,β-cyclocritral,1,2,3-trimethoxybenzene,1,2,4-trimethoxybenzene,α-ionone,β-ionone and methyl palmitate have practical contributions to the aroma of black tea and ripe tea.Among them,furan type oxidized linalool,linalool,and methyl palmitate contribute more aroma in black tea than ripe tea,while 1,2,3-trimethoxybenzene 1,2,4-trimethoxybenzene exhibit more aroma in ripe tea than black tea.