Recent Advances in Volatiles of Teas

Zheng, Xin; Li, Qing Sheng; Li, Xiang; Liang, Yue-Rong

doi:10.3390/molecules21030338

Cited by 183 publications

(149 citation statements)

References 65 publications

(112 reference statements)

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“…The volatile constituents of plant samples can be determined using different analytical techniques such as solvent extraction, hydrodistillation, simultaneous distillation‐extraction (SDE) and solid phase microextraction (SPME). Among these techniques, steam distillation was used in the present study as it gives a higher yield of volatiles compared to other methods . However, it can cause the formation of artefacts during heat treatment by thermal reactions, oxidation and degradation …”

Section: Resultssupporting

confidence: 59%

Effect of rolling methods and storage on volatile constituents of Turkish black tea

Özdemir

Tontul

Balci-Torun

et al. 2017

Flavour & Fragrance J

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The leaves of harvested tea [Camellia sinensis (L.) O. Kuntze] can be processed into different products such as black tea, green tea and oolong tea. Black tea is the mostly consumed worldwide among these products. Black tea production is achieved by a series of processing steps namely withering, rolling, fermentation, drying, sieving and packaging. Rolling is one of the most important steps in the production as it ensures uniform maceration of tea leaves and promotes oxidation reactions catalysed by phenol oxidase enzymes during the fermentation process. The rolling of tea leaves is generally performed by either Crushing‐Tearing‐Curling (CTC), rotorvane or Orthodox methods. However, in Turkey, rolling is also performed using a combination of rotorvane and orthodox which is called the “ÇAYKUR” method. The rolling method provides a unique taste and flavours. Thus, this study was conducted to compare volatile constituents of the black teas produced by the above rolling methods and to determine the volatiles during the 6‐month storage period. Some specific compounds such as 2,6‐nonadienal, 3‐hexen‐2‐one and dodecanal for ÇAYKUR, 2,5‐octanedione for Orthodox and methylpyrazine for CTC were identified to differentiate the rolling system. This study also showed that a few compounds can be used as markers of storage. The number and amounts of volatiles, especially compounds with a high molecular weight, increased by storage. In addition, the flavour quality of the teas was evaluated by the Wickremasinghe–Yamanishi ratio (WYR), Mahanta ratio (MR) and Owuor Flavour Index.

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Section: Resultssupporting

confidence: 59%

Effect of rolling methods and storage on volatile constituents of Turkish black tea

Özdemir

Tontul

Balci-Torun

et al. 2017

Flavour & Fragrance J

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“…Octadecanoic acid, also known as stearic acid, was also identified. Octadecanoic acid is a saturated fatty acid which contributes to the aroma and flavor of black tea, and while inhalation of octadecanoic acid may cause respiratory tract irritation, the compound is not considered toxic…”

Section: Discussionmentioning

confidence: 99%

Constituents of “teabacco”: A forensic analysis of cigarettes made from diverted nicotine replacement therapy lozenges in smoke‐free prisons

Mitchell

Puljević

Coomber

et al. 2018

Drug Testing and Analysis

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Following the implementation of prison smoke-free policies, there have been reports of prisoners creating substitute cigarettes made from nicotine replacement therapy patches or lozenges infused with tea leaves ("teabacco"). No studies have analyzed the chemical constituents of teabacco made from nicotine lozenges, so as to document any potential related health hazards. Teabacco samples were made by a participant who reported creating teabacco while incarcerated in a smoke-free prison in Queensland, Australia, and the process was video-recorded for replication in a laboratory. A simple linear smoking system captured the teabacco smoke for analysis. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to analyze elemental composition and gas chromatography coupled with a mass spectrometer (GC-MS) analyzed the captured smoke using the National Institute of Standards and Technology mass spectral library. Analyses determined that quantities of copper, aluminum, and lead concentrations, and levels of inhaled total particulate matter, were above recommended guidelines for safe ingestion. Analysis of teabacco smoke using GC-MS identified potentially toxic compounds catechol and nicotine. However, our findings show that smoking this form of teabacco is less harmful than smoking teabacco made from nicotine patches, or smoking traditional tobacco cigarettes. Considering the limited potential health harm of smoking teabacco made from lozenges, and that nicotine lozenges represent the only form of smoking cessation support for individuals entering smoke-free prisons, we caution against the removal of nicotine lozenges from Queensland's prisons, at least until further research directly establishes health harms associated with this form of teabacco.

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“…Group I VFC imparts inferior aroma, whereas group II VFC contributes to a positive effect on aroma. Research indicates that withering reduces the total amount of group I VFC, and increases the total amount of group II VFC (Sanyal, 2011;Zheng et al, 2016).…”

Section: Volatile Flavor Compounds (Vfc)mentioning

confidence: 99%

A Review of Withering in the Processing of Black Tea

Deb¹,

Pou²

2016

Journal of Biosystems Engineering

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Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.

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Recent Advances in Volatiles of Teas

Cited by 183 publications

References 65 publications

Effect of rolling methods and storage on volatile constituents of Turkish black tea

Effect of rolling methods and storage on volatile constituents of Turkish black tea

Constituents of “teabacco”: A forensic analysis of cigarettes made from diverted nicotine replacement therapy lozenges in smoke‐free prisons

A Review of Withering in the Processing of Black Tea

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