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J Zhejiang Univ Sci B

Title:		Aroma changes of black tea prepared from methyl jasmonate treated tea plants
Author(s):		Shi J; Wang L; Ma CY; Lv HP; Chen ZM; Lin Z;
Address:		"Key Laboratory of Tea Biology and Resource Utilization of Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China; Lin'an Agriculture Bureau, Lin'an 311300, China"
Journal Title:		J Zhejiang Univ Sci B
Year:		2014
Volume:		15
Issue:		4
Page Number:		313 - 321
DOI:		10.1631/jzus.B1300238
ISSN/ISBN:		1862-1783 (Electronic) 1673-1581 (Print) 1673-1581 (Linking)
Abstract:		"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 beta-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 beta-primeverosidase were upregulated by two and three folds, respectively, by the MeJA treatment (P<0.01); however, the gene expression of beta-glucosidase was downregulated to a half level. In general, the aroma quality of the MeJA-treated black tea was clearly improved"
Keywords:		Acetates/*pharmacology Camellia sinensis/*chemistry/*drug effects/metabolism Catechol Oxidase/genetics/metabolism Cyclopentanes/*pharmacology Food Quality Gas Chromatography-Mass Spectrometry Gene Expression/drug effects Glycoside Hydrolases/genetics/meta;
Notes:		"MedlineShi, Jiang Wang, Li Ma, Cheng-ying Lv, Hai-peng Chen, Zong-mao Lin, Zhi eng Research Support, Non-U.S. Gov't China 2014/04/09 J Zhejiang Univ Sci B. 2014 Apr; 15(4):313-21. doi: 10.1631/jzus.B1300238"