Aroma Composition of Oolong Tea and Black Tea by Brewed Extraction Method and Characterizing Compounds of Darjeeling Tea Aroma

Kawakami, Michiko; Ganguly, Subhendu N.; Banerjee, Jhumur; Kobayashi, Akio

doi:10.1021/jf00049a037

Cited by 96 publications

(55 citation statements)

References 10 publications

(10 reference statements)

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“…In previous studies, alcoholic volatile compounds such as linalool oxides, benzyl alcohol, 2-phenylethanol, and 2,6-dimethylocta-3,7-diene-2,6-diol (diol) were reported to be the main volatile compounds of Oriental Beauty. 28,33) In this study, we too detected a great increase in these compounds except for diol by comparing F and T5 (Table 2). On the other hand, we found high levels of diol even in the fresh-leaf material (F) before manufacturing, suggesting that the manufacturing process is not involved in production of diol.…”

Section: Discussionmentioning

confidence: 44%

“…Seventeen volatile compounds excluding hexanal, amyl alcohol, hexanol, (Z)-3-hexenol, hexenoic acids, and 2,6-dimethylocta-1,7-diene-3,6-diol, were detected in F before the manufacturing process, although the levels were quite low. In contrast, 2,6-dimethylocta-3,7-diene-2,6-diol (diol), which is known as one of the characteristic volatile compounds of Oriental Beauty, 28) showed the highest levels in F.…”

Section: Volatile Compoundsmentioning

confidence: 99%

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Chemical Profiling and Gene Expression Profiling during the Manufacturing Process of Taiwan Oolong Tea “Oriental Beauty”

Cho

Mizutani

Shimizu

et al. 2007

Bioscience, Biotechnology, and Biochemistry

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Section: Discussionmentioning

confidence: 44%

Section: Volatile Compoundsmentioning

confidence: 99%

Chemical Profiling and Gene Expression Profiling during the Manufacturing Process of Taiwan Oolong Tea “Oriental Beauty”

Cho

Mizutani

Shimizu

et al. 2007

Bioscience, Biotechnology, and Biochemistry

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“…The ratio of terpenoid species to nonterpenoid species has been used to classify black teas for their flavor quality. In particular, linalool and geraniol, which belong to the terpene alcohol family, always impart a sweet, flowery aroma on black tea (Sanderson et al, 1973;Vitzthum et al, 1975;Kawakami et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

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

Shi

Wang²,

et al. 2014

J. Zhejiang Univ. Sci. B

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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 MeJAtreated black tea was clearly improved.

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“…Floral tea aroma is one of the crucial components to evaluate the value and quality of tea products. The floral aroma caused by linalool, geraniol, 2-phenylethanol (2-PE), and benzyl alcohol are predominant flavor volatile compounds in oolong tea and black tea, whereas (Z)-3-hexenol adds a grassy note to green tea (Kawakami et al, 1995;Kumazawa and Masuda, 2002). However, fresh leaves of C. sinensis barely emit a slightly green note before they are processed for tea.…”

mentioning

confidence: 99%

Volatile Glycosylation in Tea Plants: Sequential Glycosylations for the Biosynthesis of Aroma β-Primeverosides Are Catalyzed by Two Camellia sinensis Glycosyltransferases

et al. 2015

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Tea plants (Camellia sinensis) store volatile organic compounds (VOCs; monoterpene, aromatic, and aliphatic alcohols) in the leaves in the form of water-soluble diglycosides, primarily as b-primeverosides (6-O-b-D-xylopyranosyl-b-D-glucopyranosides). These VOCs play a critical role in plant defenses and tea aroma quality, yet little is known about their biosynthesis and physiological roles in planta. Here, we identified two UDP-glycosyltransferases (UGTs) from C. sinensis, UGT85K11 (CsGT1) and UGT94P1 (CsGT2), converting VOCs into b-primeverosides by sequential glucosylation and xylosylation, respectively. CsGT1 exhibits a broad substrate specificity toward monoterpene, aromatic, and aliphatic alcohols to produce the respective glucosides. On the other hand, CsGT2 specifically catalyzes the xylosylation of the 69-hydroxy group of the sugar moiety of geranyl b-D-glucopyranoside, producing geranyl b-primeveroside. Homology modeling, followed by site-directed mutagenesis of CsGT2, identified a unique isoleucine-141 residue playing a crucial role in sugar donor specificity toward UDP-xylose. The transcripts of both CsGTs were mainly expressed in young leaves, along with b-PRIMEVEROSIDASE encoding a diglycoside-specific glycosidase. In conclusion, our findings reveal the mechanism of aroma b-primeveroside biosynthesis in C. sinensis. This information can be used to preserve tea aroma better during the manufacturing process and to investigate the mechanism of plant chemical defenses.

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Aroma Composition of Oolong Tea and Black Tea by Brewed Extraction Method and Characterizing Compounds of Darjeeling Tea Aroma

Cited by 96 publications

References 10 publications

Chemical Profiling and Gene Expression Profiling during the Manufacturing Process of Taiwan Oolong Tea “Oriental Beauty”

Chemical Profiling and Gene Expression Profiling during the Manufacturing Process of Taiwan Oolong Tea “Oriental Beauty”

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

Volatile Glycosylation in Tea Plants: Sequential Glycosylations for the Biosynthesis of Aroma β-Primeverosides Are Catalyzed by Two Camellia sinensis Glycosyltransferases

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