Quantitative analysis of major constituents in green tea with different plucking periods and their antioxidant activity.
Molecules. 2014 Jul 01; 19(7):9173-86.M

Abstract

The objective of this study was to determine the relationship between the plucking periods and the major constituents and the antioxidant activity in green tea. Green tea was prepared from leaves plucked from the end of April 2013 to the end of May 2013 at intervals of one week or longer. The contents of theanine, theobromine, caffeine, catechin (C), and gallocatechin gallate (GCg) were significantly decreased, whereas those of epicatechin (EC), epigallocatechin gallate (EGCg) and epigallocatechin (EGC) were significantly increased along with the period of tea leaf plucking. In addition, antioxidant activity of green tea and standard catechins was investigated using ABTS, FRAP and DPPH assays. The highest antioxidant activity was observed in relatively the oldest leaf, regardless of the assay methods used. Additionally, the order of antioxidant activity of standard catechins was as follows: EGCg≥GCg≥ECg>EGC≥GC≥EC≥C. Moreover, the cis-catechins contents were the key factor affecting the antioxidant activity of green tea in all assays employed (ABTS, r=0.731, p<0.01; FRAP, r=0.886, p<0.01; DPPH, r=0.778, p<0.01).

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ncbi.nlm.nih.gov
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Authors+Show Affiliations

Lee LS
Korea Food Research Institute, Seongnam, Kyonggi 463-746, Korea. sohee0809@hanmail.net.
Kim SH
Korea Food Research Institute, Seongnam, Kyonggi 463-746, Korea. kimsh@kfri.re.kr.
Kim YB
Korea Food Research Institute, Seongnam, Kyonggi 463-746, Korea. kybaaa@kfri.re.kr.
Kim YC
Korea Food Research Institute, Seongnam, Kyonggi 463-746, Korea. yckim@kfri.re.kr.

MeSH

BenzothiazolesBiphenyl CompoundsCaffeineCamellia sinensisCatechinFree Radical ScavengersFree RadicalsGlutamatesPicratesPlant ExtractsPlant LeavesSulfonic Acids

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

24988187