Differential behaviors of tea catechins under thermal processing: Formation of non-enzymatic oligomers

Fan, Fangyuan; Shi, Meng; Nie, Ying; Zhao, Yue; Ye, Jian-Hui; Liang, Yue-Rong

doi:10.1016/j.foodchem.2015.09.056

Cited by 106 publications

(83 citation statements)

References 36 publications

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“…Previous research reported that catechins were quite unstable at high temperatures, since chemical conversions by epimerisation, hydrolysis and oxidation/condensation reactions easily occur (Wang et al ., ). These experimental results for the change behaviour of catechins during the practical heating process were as predicted in model experiments (Fan et al ., ).…”

Section: Resultsmentioning

confidence: 99%

Hot air drying of tea flowers: effect of experimental temperatures on drying kinetics, bioactive compounds and quality attributes

Shi

et al. 2018

Int J of Food Sci Tech

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Summary The drying process is important for the quality and value of tea flower products. In the present work, the effects of different hot air drying (HAD) temperatures from 60 to 120 °C on drying kinetics, bioactive compounds (catechins, flavonol glycosides and triterpenoid saponins) and quality attributes (volatile compounds, colours and antioxidant properties) of tea flowers were systematically evaluated. The results showed that higher drying temperature resulted in a shorter drying time but with greater loss of bioactive compounds and quality attributes. Flowers subjected to HAD at 60 °C showed the highest bioactive contents and quality attributes of all HAD samples and the quality of HAD 60 °C samples were close to that of freeze‐dried samples. Taking account of the production efficiency and energy consumption, the tea flowers dried at 60 °C for 180 min was preferred. These findings provide a guide for the processing of tea flowers with the aim of improving the overall quality of the product.

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Section: Resultsmentioning

confidence: 99%

Hot air drying of tea flowers: effect of experimental temperatures on drying kinetics, bioactive compounds and quality attributes

Shi

et al. 2018

Int J of Food Sci Tech

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“…Our previous study reported that catechin was polymerized to proanthocyanidin in neutral or alkaline aqueous with blue light illumination (Liang et al, ). Fan et al () reported that oligomerization occurs in catechins during high temperature and long heat treatment (Fan et al, ). The proposed intermediate of this study can explain the reasonable pathway of the polymerized catechins to proanthocyanidin found in most pigmented plants.…”

Section: Resultsmentioning

confidence: 99%

Using chromatography and mass spectrometry to monitor isomerization of catechin in alkaline aqueous with thermal processing

Chen

Liang

2017

J Food Process Preserv

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Polyphenols are associated with a wide range of physiological properties. Catechins are a class of polyphenolic flavonoids predominantly found in foods and beverages that are chemically unstable.This study investigated the effects of thermal processing and pH on the structural changes to catechins and examined how these effects impact the antioxidant capacity of these molecules. The results indicated the total phenolic contents of catechin were increased after alkalifying and ther- Practical applicationsHeating process and pH adjustment are used to meet hygienic requirements and maintain flavor during tea infusion processing in tea beverage manufacturing. Catechins account for the largest sum of polyphenols found in green tea. Basification and heating could catalyze the isomerization of catechin through an opened heterocyclic ring pathway. Catechin remains stable in acidic solutions during thermal processing, thus, avoiding changes of quality.

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“…The configuration of chiral compounds may show different activities, flavor, and taste (Figure ). Furthermore, heating of EGCG can produce many EGCG dimers, such as theasinensins, which could also affect the quality of roasted tea (Fan et al., ). The nucleophilic properties of catechins can also form many catechin–carbonyl and catechin–theanine conjugates (Meng et al., ).…”

Section: Tea Chemistrymentioning

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

346

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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Differential behaviors of tea catechins under thermal processing: Formation of non-enzymatic oligomers

Cited by 106 publications

References 36 publications

Hot air drying of tea flowers: effect of experimental temperatures on drying kinetics, bioactive compounds and quality attributes

Hot air drying of tea flowers: effect of experimental temperatures on drying kinetics, bioactive compounds and quality attributes

Using chromatography and mass spectrometry to monitor isomerization of catechin in alkaline aqueous with thermal processing

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

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