茶小绿叶蝉危害对金萱红茶挥发性成分的影响

Effects of Tea Green Leafhoppers Empoasca vitis Gothe Hazards on Volatiles of Jin Xuan Black Tea

本研究以金萱为材料,通过顶空固相微萃取-气质联用仪(HS-SPME-GC/MS),研究茶小绿叶蝉危害对金萱红茶挥发性成分的影响。结果表明:金萱鲜叶和红茶挥发性成分以醇类为主,且醇类中92%以上是萜醇。茶小绿叶蝉危害鲜叶后,萜醇含量降低,脂肪醇、芳香醇、萜酮、脂肪酮、酯类和烃类增加;红茶挥发性成分中萜醇、脂肪醇、萜酮、脂肪酮、烃类和酸类含量降低,酯类增加。主成分和聚类分析结果表明,鲜叶与红茶挥发性成分轮廓不同,萜醇和酯类是区分不同危害程度鲜叶及其红茶的主要挥发性成分。鲜叶特征成分以萜醇(β-芳樟醇、橙花醇、顺-氧化芳樟醇Ⅱ、顺-氧化芳樟醇Ⅰ、香叶醇)为主;茶小绿叶蝉危害后,萜醇减少,醛类(β-环柠檬醛、3,7-二甲基-2,6-二辛烯醛、苯甲醛)增加。不同危害程度鲜叶加工的红茶其特征性的酯类和萜醇挥发性成分各不相同。

The volatiles from healthy intact tea shoots, tea shoots damaged by the tea green leafhopper（Empoasca vitis Gothe） and their black teas were analyzed by gas chromatography and mass spectrometry（GC-MS）, extracted by headspace solid phase microextraction（HS-SPME）. Jin xuan was selected as masteries. The results showed that alcohols were the main volatiles, of which terpene alcohols accounting for above ninety-two percentage in tea shoots and black teas. For tea shoots damaged by tea green leafhopper, terpene alcohols decreased, while these volatiles（fatty alcohols, aromatic alcohols, terpene ketones, aliphatic ketones, esters and hydrocarbons） increased. Terpene alcohols, fatty alcohols, terpene ketones and aliphatic ketones decreased in black teas made by damaged shoots. But esters increased in black teas made by damaged shoots. Based on principal component analysis（PCA） and cluster analysis, the volatiles of tea shoots and black teas could be divided into two distinct classes, terpene alcohols and esters could distinguish from the damaged tea shoots and its black teas. PCA results for main volatiles showed that terpene alcohols（including β-linalool, neroli, linalool-oxide ii, linalool-oxide I, geraniol）, were the unique volatiles in intact tea shoots. For the damaged tea shoots, terpene alcohols decreased and aldehydes（β-cyclocitral, 3,7-dimethyl-2,6-octadienal, benzaldehyde） increased. Three kinds of black teas implied distinctive esters and terpene alcohols.