Flavonoids, phenolic acids, alkaloids and theanine in different types of authentic Chinese white tea samples

Tan, Junfeng; Engelhardt, Ulrich H.; Zhi, Lin; Kaiser, Nils; Maiwald, Beate

doi:10.1016/j.jfca.2016.12.011

Cited by 97 publications

(68 citation statements)

References 20 publications

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“…To date, more than twenty flavonol glycosides have been reported in different teas. The compositions of flavonol glycosides are varied with tea cultivar, leaf maturity, harvest season and tea type (Dou et al, 2007;Lee et al, 2008;Zhao et al, 2011;Wu et al, 2012Wu et al, , 2016Tan et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

“…The effect of production on the composition of flavonol glycosides in tea products has not been systematically studied. Comparative studies were carried out to investigate the levels of flavonol glycosides between different types of tea products, attempting to understand the impact of manufacturing procedure on these compounds (Price et al, 1998;Unachukwu et al, 2010;van der Hooft et al, 2012;Jiang et al, 2015;Tan et al, 2017). However, the commercial tea products are normally collected from different company (Price et al, 1998;Tan et al, 2017), and it is difficult to control tea cultivar and leaf maturity which both affect the composition of flavonol glycosides.…”

Section: Introductionmentioning

confidence: 99%

“…Comparative studies were carried out to investigate the levels of flavonol glycosides between different types of tea products, attempting to understand the impact of manufacturing procedure on these compounds (Price et al, 1998;Unachukwu et al, 2010;van der Hooft et al, 2012;Jiang et al, 2015;Tan et al, 2017). However, the commercial tea products are normally collected from different company (Price et al, 1998;Tan et al, 2017), and it is difficult to control tea cultivar and leaf maturity which both affect the composition of flavonol glycosides. The degradation of flavonol glycosides was associated with the fermentation process of black tea (Price et al, 1998), and this conclusion was testified by an in vitro fermentation study with polyphenol peroxidase (Finger, 1994).…”

Section: Introductionmentioning

confidence: 99%

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Dynamic changes in flavonol glycosides during production of green, yellow, white, oolong and black teas from Camellia sinensis L. (cv. Fudingdabaicha)

Fang

Song

et al. 2018

Int J of Food Sci Tech

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Summary Flavonol glycosides with low thresholds are important flavour substances in tea leaves. This study monitored the dynamic changes in flavonol glycosides during the production of different teas. The fresh leaves of cv. Fudingdabaicha with 15.77 mg g−1 of total flavonol glycosides (TFG) were respectively processed into green, yellow, white, oolong and black teas. A reduction of TFG was observed for different teas, amongst which black tea contained the lowest level of TFG (9.83 mg g−1), followed by oolong tea (11.96 mg g−1), while green, yellow and white teas contained similar levels of TFG (~13.70 mg g−1). Fixation was crucial to maintain the stability of flavonol glycosides due to its inactivation effect on enzymes at high temperature. Principal component analysis results indicated that flavonol glycosides were vulnerable to fermentation, and the stabilities of flavonol glycosides were related with aglycone and glycoside moiety.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dynamic changes in flavonol glycosides during production of green, yellow, white, oolong and black teas from Camellia sinensis L. (cv. Fudingdabaicha)

Fang

Song

et al. 2018

Int J of Food Sci Tech

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“…Some authors 17 reported that Mn II ions can form strong complexes in the presence of organic substances, such as flavonoids, humic and fulvic acids. Black tea is rich in these compounds, 3,28 and the complexes formed with Mn II are non-electroactive. 17 Due to this, complete destruction of the organic substance is recommended before electrochemical measurements in order to detect the total content of manganese.…”

Section: Applicationmentioning

confidence: 99%

Voltammetric Determination of Free and Total Manganese in Tea Infusions

Elias

Castro

Muñoz

et al. 2020

J. Braz. Chem. Soc.

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Tea infusions are a source of mineral nutrients, including manganese. Although it is classified as an essential element, the excess of manganese is toxic for humans and its toxicity depends on its bioavailability. In this context, we propose a simple procedure to determine free and total manganese in black tea infusions by square-wave voltammetry (SWV). Free manganese was directly quantified in the samples after simple sample dilution in 0.1 mol L −1 acetic acid/acetate buffer (pH = 4.5) while total manganese determination was carried out after sample digestion with oxidant mixture (HNO 3 + H 2 O 2). For comparison, cloud point extraction was performed to remove organic-bound manganese and the content of free metal (not extracted) measured by flame atomic absorption spectrometry (F AAS) agrees with the values obtained by the proposed SWV procedure. The limit of detection and quantification were estimated for manganese determination as 0.06 and 0.20 µg L −1 , respectively, with a linear range observed between 20 and 250 µg L −1. The coefficient of variation was 9.7% (50 µg L −1 , n = 10). The procedure was applied to determination of free and total manganese in black tea bags and the results were compared with literature procedures employing F AAS.

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“…White tea of Camellia sinensis L. is produced from the youngest part of the leaf (leaf bud). The most common active compounds are polyphenols such as epigallocatechin gallate (EGCG) and other catechin derivatives [1,2]. Other ingredients found in white tea are caffeine, theobromine, and theophylline.…”

Section: Introductionmentioning

confidence: 99%

Optimization of a Novel Kinetic-Assisted Infundation for Rich-Egcg and Polyphenols of White Tea (Camellia Sinensis) Using Central Composite Design

Shiyan¹,

Hertiani²,

Martien³

et al. 2018

Int J App Pharm

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Objective: This research aimed to find modeling and optimization of a novel kinetic-assisted infundation for rich-epigallocatechin gallate (EGCG) and polyphenols extraction from white tea leaf (Camellia sinensis L.).Methods: The optimal conditions for the best extraction of kinetic-assisted infundation were determined using central composite design. The content of EGCG, catechin, gallic acid, caffeine, theobromine, and theophylline was quantified using high-performance liquid chromatography with ultraviolet detection (HPLC/UV-detection). The total polyphenolic content (TPC) and total flavonoid content (TFC) was measured using the spectrophotometric method. The semi-purified extract was characterized by HPLC, fourier transform infrared spectrophotometry-universal attenuated total reflectance (FTIR-UATR), and powder-X ray diffraction (P-XRD). The extraction mechanism of target compounds was analyzed using scanning electron microscopy (SEM) qualitatively.Results: The optimum process for the rich-EGCG and polyphenolic extraction using kinetic-assisted infundation was the concentration of simplicia 14.75 %, the stir rate 440 rpm, and extraction time 12.31 min. The yield of extracts, TPC, TFC, EGCG, caffeine, gallic acid, and theobromine contents in the optimal extraction process were 9.34 %, 70.97 %, 13.95 %, 29.02 %, 11.95 %, 1.33 %, and 0.33 %, respectively.Conclusion: The kinetic-assisted infundation method proved to be easy to apply with good results as an alternative technique for extracting polyphenolic compounds and rich-EGCG from white tea leaves.

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Flavonoids, phenolic acids, alkaloids and theanine in different types of authentic Chinese white tea samples

Cited by 97 publications

References 20 publications

Dynamic changes in flavonol glycosides during production of green, yellow, white, oolong and black teas from Camellia sinensis L. (cv. Fudingdabaicha)

Dynamic changes in flavonol glycosides during production of green, yellow, white, oolong and black teas from Camellia sinensis L. (cv. Fudingdabaicha)

Voltammetric Determination of Free and Total Manganese in Tea Infusions

Optimization of a Novel Kinetic-Assisted Infundation for Rich-Egcg and Polyphenols of White Tea (Camellia Sinensis) Using Central Composite Design

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