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

J Zhejiang Univ Sci B. 2014 Apr;15(4):313-21. doi: 10.1631/jzus.B1300238.

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 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 (P<0.01); however, the gene expression of β-glucosidase was downregulated to a half level. In general, the aroma quality of the MeJA-treated black tea was clearly improved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / pharmacology*
  • Camellia sinensis / chemistry*
  • Camellia sinensis / drug effects*
  • Camellia sinensis / metabolism
  • Catechol Oxidase / genetics
  • Catechol Oxidase / metabolism
  • Cyclopentanes / pharmacology*
  • Food Quality
  • Gas Chromatography-Mass Spectrometry
  • Gene Expression / drug effects
  • Glycoside Hydrolases / genetics
  • Glycoside Hydrolases / metabolism
  • Humans
  • Odorants / analysis*
  • Oxylipins / pharmacology*
  • Solid Phase Microextraction
  • Tea / chemistry*
  • Volatile Organic Compounds / analysis
  • beta-Glucosidase / genetics
  • beta-Glucosidase / metabolism

Substances

  • Acetates
  • Cyclopentanes
  • Oxylipins
  • Tea
  • Volatile Organic Compounds
  • methyl jasmonate
  • Catechol Oxidase
  • Glycoside Hydrolases
  • beta-primeverosidase
  • beta-Glucosidase