Oxidation mechanism of black tea pigment theaflavin by peroxidase

Kusano, Rie; Matsuo, Yosuke; Saito, Yoshinori; Tanaka, Takashi

doi:10.1016/j.tetlet.2015.07.037

Cited by 35 publications

(27 citation statements)

References 24 publications

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“…Through continuous oxidation of tri-hydroxyls of gallate and di-hydroxyls of catechin, theadibenzotropolones and theatribenzotropolones containing two and three benzotropolones moieties formed, respectively, (Sang, Tian, Stark, Yang, & Ho, 2004). On the other hand, through decarboxylation, TFs can produce theanaphthoquinones and theacoumarins, which no longer have the benzotropolone moiety (Kusano, Matsuo, Saito, & Tanaka, 2015).…”

Section: Novel Flavan-3-ols Derivativesmentioning

confidence: 99%

Chemistry and Biological Activities of Processed Camellia sinensis Teas: A Comprehensive Review

Liang

Zhou

et al. 2019

Comp Rev Food Sci Food Safe

362

237

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Tea is a typical processed beverage from the fresh leaves of Camellia sinensis [Camellia sinensis (L.) O. Kuntze] or Camellia assamica [Camellia sinensis var. assamica (Mast.) Kitamura] through different manufacturing techniques. The secondary metabolites of fresh tea leaves are mainly flavan‐3‐ols, phenolic acids, purine alkaloids, condensed tannins, hydrolysable tannins, saponins, flavonols, and their glycoside forms. During the processing, tea leaves go through several steps, such as withering, rolling, fermentation, postfermentation, and roasting (drying) to produce different types of tea. After processing, theaflavins, thearubigins, and flavan‐3‐ols derivatives emerge as the newly formed compounds with a corresponding decrease in concentrations of catechins. Each type of tea has its own critical process and presents unique chemical composition and flavor. The components among different teas also cause significant changes in their biological activities both in vitro and in vivo. In the present review, the progress of tea chemistry and the effects of individual unit operation on components were comprehensively described. The health benefits of tea were also reviewed based on the human epidemiological and clinical studies. Although there have been multiple studies about the tea chemistry and biological activities, most of existing results are related to tea polyphenols, especially (‐)‐epigallocatechin gallate. Other compounds, including the novel compounds, as well as isomers of amino acids and catechins, have not been explored in depth.

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Section: Novel Flavan-3-ols Derivativesmentioning

confidence: 99%

Chemistry and Biological Activities of Processed Camellia sinensis Teas: A Comprehensive Review

Liang

Zhou

et al. 2019

Comp Rev Food Sci Food Safe

362

237

View full text Add to dashboard Cite

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“…Green tea, that is not subject to fermentation, contains more catechins than fermented teas such as oolong (partial fermentation) or black and Pu-erh teas (complete fermentation) (Toschi et al 2000 ). During fermentation of O 2 oxidoreductase, involving polyphenol oxidase, monophenol monooxygenase and o-diphenol, about 75% of catechins contained in leaves are subject to enzymatic oxidation (Donejko et al 2013 ; Kusano et al 2015 ; Kuhnert 2010 ). The content and type of catechins in green tea depends on the variety of tea, climate and growing conditions (Toschi et al 2000 ).…”

Section: The Antioxidant Properties Of Teamentioning

confidence: 99%

“…Theaflavins are formed at the first stage of fermentation. At the following stages oxidation products are transformed into thearubigins (Bailey et al 1994 ; Kusano et al 2015 ). So far at least 28 derivatives of theaflavin have been recognized.…”

Section: The Antioxidant Properties Of Teamentioning

confidence: 99%

Protective effect of tea against lead and cadmium-induced oxidative stress—a review

Winiarska-Mieczan

2018

Biometals

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Exposure to Cd and Pb reduces the activity of antioxidant enzymes, which points to a decrease in the antioxidant potential of the body as a result of supplying factors which enhance cellular oxidation processes. Man is exposed to the effects of toxic metals because they are present in the environment, including in food. Since no effective ways to reduce the concentrations of Cd an Pb in food exist, studies are undertaken to develop methods of reducing their toxic effect on the body through chelating these metals using nutrients (which reduces their absorption by tissues) or increasing the oxidative capacity of the body (which decreases the possibility of inducing oxidative damage to internal organs). Studies performed on laboratory animals have shown that the use of tea infusions fulfil both functions.

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“…The amount of catechins is reduced to less than 10% of its original content in black tea (Wang, Provan, & Helliwell, ). TF are formed by enzymatic oxidation and condensation of catechins with di‐ and trihydroxylated B rings (Kusano, Matsuo, Saito, & Tanaka, ; Lian, Thiru, Parry, & Moore, ). Level of TF and their fractions (Panigrahi, Bhol, & Das, ; Qu et al, ; Wright, Mphangwe, Nyirenda, & Apostolides, ), catechin fractions and ratio between polyphenoloxidase and catechins (Lopez, Thomas, Pius, Kumar, & Muraleedharan, ; Saravanan, John, Raj Kumar, Pius, & Sasikumar, ) have been considered as reliable black tea quality parameters.…”

Section: Introductionmentioning

confidence: 99%

Analysis and modeling of major polyphenols during oxidation in production of black tea

Das

Samanta

Datta

2019

J Food Process Preserv

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Analysis of four different catechins, four theaflavins (TF), and thearubigin (TR) in oxidizing macerated CTC (crush–tear–curl) and rolled orthodox leaves of TV25 clone was done. Tea leaves were oxidized at different air temperatures (20, 25, 30, and 35°C) and thickness of oxidizing leaf bed (2 and 5 cm). Rate of depletion of catechins was modeled using Michaelis–Menten equation. Depletion of dihydroxylated catechins (EC, ECG) was found to be more affected by change in air temperature than trihydroxylated catechins (EGC, EGCG). Amount of maximum total TF at different temperatures was in the range of 1.19%–1.3% for CTC‐macerated leaves and 0.33%–0.43% for rolled orthodox leaves. Quadratic and linear regression equations, developed to model the change in TF and TR contents, respectively, were good fit. Bed thickness does not have any significant effect on TF content in both CTC and orthodox leaves as revealed from ANOVA. Practical applications Oxidation or fermentation of macerated leaves is a crucial step in black tea processing that needs to be carefully monitored. Tea processing facilities maintain only air humidity level during fermentation. Air temperature is also an important factor affecting the degradation of catechins and formation of different pigment compounds. Optimum amount of unoxidized catechins and oxidized compounds TF and TR affects the quality of final product. Modeling of catechin, TF, and TR contents in oxidizing leaves will help to manipulate processing conditions such as air temperature, duration, and bed thickness to produce good quality black tea.

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Oxidation mechanism of black tea pigment theaflavin by peroxidase

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Cited by 35 publications

References 24 publications

Chemistry and Biological Activities of Processed Camellia sinensis Teas: A Comprehensive Review

Chemistry and Biological Activities of Processed Camellia sinensis Teas: A Comprehensive Review

Protective effect of tea against lead and cadmium-induced oxidative stress—a review

Analysis and modeling of major polyphenols during oxidation in production of black tea

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