The Role of Diglycosides as Tea Aroma Precursors:  Synthesis of Tea Diglycosides and Specificity of Glycosidases in Tea Leaves

1997 ◽  
Vol 45 (7) ◽  
pp. 2674-2678 ◽  
Author(s):  
Sachiko Matsumura ◽  
Shunya Takahashi ◽  
Mariko Nishikitani ◽  
Kikue Kubota ◽  
Akio Kobayashi
Keyword(s):  
Tea Leaves ◽  
Aroma Precursors

The potential role of tea in periodontal therapy: An updated review

2020 ◽  
Vol 17 ◽  
Author(s):  
Ali Forouzanfar ◽  
Hamideh Sadat Mohammadipour ◽  
Fatemeh Forouzanfar
Keyword(s):  
Green Tea ◽  
Potential Role ◽  
Wide Spectrum ◽  
Periodontal Diseases ◽  
Herbal Remedies ◽  
World Population ◽  
Tea Leaves ◽  
The World ◽  
Green Tea Leaves

: Periodontal diseases are highly prevalent and can affect high percentage of the world population. Oxidative stress and inflammation plays an important role in the pathogenesis of periodontal diseases. Nowadays, more attention has been focused on the herbal remedies in the field of drug discovery. Green tea is an important source of polyphenol antioxidants, it has long been used as a beverage worldwide. The most interesting polyphenol components of green tea leaves that are related with health benefits are the catechins. Taken together this review suggested that green tea with its wide spectrum of activities could be a healthy alternative for controlling the damaging reactions seen in periodontal diseases.

Role of Glycosidic Aroma Precursors on the odorant profiles of Grenache noir and Syrah Wines from the Rhone valley. Part 1: sensory study

OENO One ◽  
2009 ◽  
Vol 43 (4) ◽  
pp. 199
Author(s):  
Marie A. Segurel ◽  
Raymond L. Baumes ◽  
Christine Riou ◽  
Alain Razungles
Keyword(s):  
Descriptive Analysis ◽  
Natural Aging ◽  
Quantitative Descriptive Analysis ◽  
Sensory Study ◽  
Trained Panel ◽  
Aroma Precursors ◽  
Quantitative Descriptive ◽  
Rhone Valley ◽  
The Impact

<p style="text-align: justify;"><strong>Aims</strong>: The aim of this study was to demonstrate the impact of the volatile compounds, arising from glycosidic precursors contained in the berries of Vitis vinifera L.cv Syrah and Grenache noir varieties, on wine aromas from these varieties.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The sensory analysis was used to compare Grenache noir and Syrah wines. The role played by the glycosidic precursors on the future odorant profile of the wines from both varieties was demonstrated in an experiment by increasing their natural content in glycosides. Then, odorant compounds were generated by aging treatments, heating at 45 °C for 3 weeks, preceded or not by enzyme addition, or natural aging for 18 months. The wines were then submitted to a selected and trained panel. Samples were compared using triangular test. Furthermore, a quantitative descriptive analysis was carried out to determine the aroma attributes describing and discriminating the wines from the two varieties.</p><p style="text-align: justify;"><strong>Conclusion</strong>: The glycoconjugates increased the global aromatic complexity, and enhanced the fruity aromas in Grenache wines and the leather or olive aromas in Syrah wines. The use of glycosidase enzymes led to a stewed fruit character in Grenache wines, whereas in Syrah wines, the samples enriched with glycosides differed according to the « terroir ».</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: This study showed the impact of the glycosidic fraction of the grapes on the varietal aroma of wines. Furthermore, comparisons of the results obtained by both aging techniques highlight the experimental interest of the aging model but also its limits.</p>

scholarly journals Role of Ethylene in the Biosynthetic Pathway of Related-aroma Volatiles Derived from Fatty Acids in Oriental Sweet Melon

2016 ◽  
Vol 141 (4) ◽  
pp. 327-338 ◽  
Author(s):  
Yan Li ◽  
Hongyan Qi ◽  
Yazhong Jin ◽  
Xiaobin Tian ◽  
Linlin Sui ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Biosynthetic Pathway ◽  
Expression Patterns ◽  
Gene Families ◽  
Hydroperoxide Lyase ◽  
Straight Chain ◽  
Alcohol Acetyltransferase ◽  
Key Enzyme ◽  
Aroma Precursors

The catabolism of fatty acid (FA) is regarded as a key pathway of aroma volatile compounds in oriental sweet melon (Cucumis melo var. makuwa). In our research, two cultivars of oriental sweet melon, Caihong7 and Tianbao, were employed to illuminate which step of the biosynthetic pathway of aroma compounds could be regulated by ethylene (ETH). The role of ETH in determining the profiles of straight-chain aroma volatile compounds, levels of FA as aroma precursors, activities of aroma-related enzymes derived from FA pathway, and expression patterns of key enzymes were investigated. Overall, exogenous application of ETH increased the production rates of endogenous ETH and levels of FA. Compared with control, the level of straight-chain esters, especially the acetate, hexanoate, and hexyl esters, was significantly increased by ETH, whereas the content of alcohol and aldehyde reduced. In addition, the metabolism of free FA included linoleic acid (LA), linolenic acid (LeA), and oleic acid (OA) appeared to be ETH-dependent. The activities of lipoxygenase (LOX), alcohol dehydrogenase (ADH), and alcohol acetyltransferase (AAT) as well as the expression patterns of Cm-ADH1, Cm-ADH2, Cm-AAT1, and Cm-AAT4 were positively regulated by ETH. In contrast, hydroperoxide lyase (HPL) and Cm-AAT2 and Cm-AAT3 seemed to be independent of ETH modulation. These results suggested that the dissimilation of FA included LA, LeA, and OA into the acetate, hexanoate, and hexyl esters mainly through ETH regulating the LOX pathway by enhancing the expression of particular members of aroma-related key enzyme gene families as well as the activities of dehydrogenation and esterification.

scholarly journals Integrative Transcriptomic and Metabolic Analyses Provide Insights into the Role of Trichomes in Tea Plant (Camellia Sinensis)

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 311 ◽  
Author(s):  
Hongli Cao ◽  
Jiamin Li ◽  
Yijun Ye ◽  
Hongzheng Lin ◽  
Zhilong Hao ◽  
...  
Keyword(s):  
Regulatory Mechanism ◽  
Tea Plant ◽  
Germplasm Resources ◽  
Rna Seq ◽  
Structural Genes ◽  
Tea Leaves ◽  
Plant Growth And Development ◽  
Tea Quality ◽  
Insight Into

Trichomes, which develop from epidermal cells, are regarded as one of the key features that are involved in the evaluation of tea quality and tea germplasm resources. The metabolites from trichomes have been well characterized in tea products. However, little is known regarding the metabolites in fresh tea trichomes and the molecular differences in trichomes and tea leaves per se. In this study, we developed a method to collect trichomes from tea plant tender shoots, and their main secondary metabolites, including catechins, caffeine, amino acids, and aroma compounds, were determined. We found that the majority of these compounds were significantly less abundant in trichomes than in tea leaves. RNA-Seq was used to investigate the differences in the molecular regulatory mechanism between trichomes and leaves to gain further insight into the differences in trichomes and tea leaves. In total, 52.96 Gb of clean data were generated, and 6560 differentially expressed genes (DEGs), including 4471 upregulated and 2089 downregulated genes, were identified in the trichomes vs. leaves comparison. Notably, the structural genes of the major metabolite biosynthesis pathways, transcription factors, and other key DEGs were identified and comparatively analyzed between trichomes and leaves, while trichome-specific genes were also identified. Our results provide new insights into the differences between tea trichomes and leaves at the metabolic and transcriptomic levels, and open up new doors to further recognize and re-evaluate the role of trichomes in tea quality formation and tea plant growth and development.

scholarly journals (S)-Linalyl, 2-Phenylethyl, and Benzyl Disaccharide Glycosides Isolated as Aroma Precursors from Oolong Tea Leaves

1994 ◽  
Vol 58 (8) ◽  
pp. 1532-1534 ◽  
Author(s):  
Wenfei Guo ◽  
Ryuji Hosoi ◽  
Kanzo Sakata ◽  
Naoharu Watanabe ◽  
Akihito Yagi ◽  
...  
Keyword(s):  
Tea Leaves ◽  
Oolong Tea ◽  
Aroma Precursors

cis- andtrans-Linalool 3,7-Oxides and Methyl Salicylate Glycosides and (Z)-3-Hexenylβ-D-Glucopyranoside as Aroma Precursors from Tea Leaves for Oolong Tea

1996 ◽  
Vol 60 (11) ◽  
pp. 1815-1819 ◽  
Author(s):  
Jae-Hak Moon ◽  
Naoharu Watanabe ◽  
Yasuyuki Ijima ◽  
Akihito Yagi ◽  
Kanzo Sakata
Keyword(s):  
Methyl Salicylate ◽  
Tea Leaves ◽  
Oolong Tea ◽  
Aroma Precursors

Specificity of Glycosidases from Tea Leaves toward Glycidic Tea Aroma Precursors

2001 ◽  
pp. 167-175 ◽  
Author(s):  
Akio Kobayashi ◽  
Kikue Kubota ◽  
Dongmei Wang ◽  
Takako Yoshimura
Keyword(s):  
Tea Leaves ◽  
Aroma Precursors

scholarly journals Role of Glycosidic Aroma Precursors on the odorant profiles of Grenache noir and Syrah Wines from the Rhone valley. Part 2: characterisation of derived compounds

OENO One ◽  
2009 ◽  
Vol 43 (4) ◽  
pp. 213
Author(s):  
Marie A. Segurel ◽  
Raymond L. Baumes ◽  
Dominique Langlois ◽  
Christine Riou ◽  
Alain Razungles
Keyword(s):  
Multivariate Analyses ◽  
Accelerated Aging ◽  
Natural Aging ◽  
Aroma Compounds ◽  
Varietal Differences ◽  
Aroma Precursors ◽  
Rhone Valley ◽  
Grape Varieties ◽  
Related Compounds

<p style="text-align: justify;"><strong>Aims</strong>: Grenache noir and Syrah are the predominant grape varieties in the French Rhone valley vineyard. This study aimed at identifying the odorants generated from glycoconjugates extracted from wines made with Grenache noir and Syrah.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Synthetic model wines enriched with glycoconjugates, treated or not with enzymes, were stored at 45 °C for 3 weeks, or at 13 °C for 18 months. Aromas generated were extracted and analyzed by GC-Olfactometry (only samples from accelerated aging) and were further quantitatively determined by GC-MS. Analysis of the extracts allowed to identify 49 odorants, including 27 that could be aglycons, or related compounds, of glycoconjugates from the grapes. In addition, the active compounds were quantified in similar experiments led in conditions of natural aging for 18 months.</p><p style="text-align: justify;"><strong>Conclusion</strong>: The two varieties, Grenache noir and Syrah, were distinguishable by 14 odorant zones. Multivariate analyses (PCA) performed with the amounts of aroma compounds formed during both model and natural aging confirmed the effect of the glycosidase treatment on the acceleration of the aroma compounds formation and on the increase of the varietal differences of the wines.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: GC-Olfactometry coupled with GCMS were good techniques to indentify and apreciate the odorants generated from glycoconjugates in the wines of Syrah and Grenache Noir, but in the context of a blend of odors, these techniques showed their limits and did not permit to determine the real impact of a molecule in the global aroma of the wine perceived by the taster. Other methods as additive techniques should be used to complete this study.</p>

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