Aroma changes of black tea prepared from methyl jasmonate treated tea plants  

茉莉酸甲酯诱导茶鲜叶制成的红茶中香气成分变化(英文)

作　　者：Jiang SHI Li WANG Cheng-ying MA Hai-peng LV Zong-mao CHEN Zhi LIN 

机构地区：[1]Key Laboratory of Tea Biology and Resource Utilization of Ministry of Agriculture,Tea Research Institute,Chinese Academy of Agricultural Sciences [2]Graduate School of Chinese Academy of Agricultural Sciences [3]Lin’an Agriculture Bureau

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2014年第4期313-321,共9页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：supported by the National Natural Science Foundation of China(No.31270734);the Construction Project of Modern Agricultural Technology System(No.CARS-23);the Zhejiang Provincial Science and Technology Plan Project(No.2007C12G3020014),China

摘　　要：Methyl jasmonate（MeJA） was widely applied in promoting food quality.Aroma is one of the key indicators in judging the quality of tea.This study examined the effect of exogenous MeJA treatment on tea aroma.The aroma components in black tea prepared from MeJA-treated fresh tea leaves were extracted using headspace solid-phase microextraction（HS-SPME） and were analyzed using gas chromatography-mass spectrometry（GC-MS） and GC-olfactometry（GC-O）.Forty-five volatile compounds were identified.The results revealed that the MeJA-treated black tea had higher levels of terpene alcohols and hexenyl esters than the untreated tea.Moreover,several newly components,including copaene,cubenol,and indole,were induced by the MeJA treatment.The activities of polyphenol oxidase and β-glucosidase in fresh tea leaves changed after the MeJA treatment.Quantitative real-time polymerase chain reaction（qRT-PCR） analysis indicated that the gene expression levels of polyphenol oxidase and β-primeverosidase were upregulated by two and three folds,respectively,by the MeJA treatment（P0.01）; however,the gene expression of β-glucosidase was downregulated to a half level.In general,the aroma quality of the MeJAtreated black tea was clearly improved.研究目的:为茉莉酸甲酯诱导来提高茶叶香气品质提供理论依据,为新型花香红茶的研制提供技术支持。创新要点:首次将茉莉酸甲酯应用于诱导茶叶香气品质提高,初步验证了茶叶香气品质提高的本质原因:相关酶活性提高,基因表达上调。研究方法:采用顶空固相微萃取法(HS-SPME)对红茶香气进行富集,气相色谱-质谱联用仪(GC-MS)进行解吸附分析,实时定量多聚酶链式反应(qRT-PCR)分析茶鲜叶中香气相关酶基因表达。重要结论:茉莉酸甲酯诱导后的茶鲜叶中多酚氧化酶(PPO)活性上升,β-葡萄糖苷酶活性下降;PPO和β-樱草糖苷酶基因表达上调,β-葡萄糖苷酶基因表达下调。茉莉酸甲酯诱导后的茶鲜叶能明显提高由其制成的红茶香气品质,且萜烯醇类和萜烯类含量明显提高。

关 键 词：AROMA Black tea Methyl jasmonate（MeJA） Headspace solid-phase microextraction（HS-SPME） Gas chromatography-mass spectrometry（GC-MS） Gas chromatography-olfactometry（GC-O） Gene expression 

分 类 号：TS272[农业科学—茶叶生产加工]