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The chemical or metabolic compositions of tea (Camellia sinensis) varies according to numerous factors, such as geographical origin, cultivar, climate, plucking position, and horticultural practices. However, how the age of tea plants affects the metabolite compositions of tea leaves has not been reported yet. Therefore, we extended the metabolomic approach to the investigation of the age-related differences of tea leaf metabolites in the fresh leaves collected from tea plants aged 8 and 25 years. Multivariate statistical analysis with comprehensive metabolite profiles analyzed by 1H NMR spectroscopy showed the clear metabolic differentiation between the fresh tea leaves from different ages of the tea plants. Of the various tea leaf metabolites varied according to the age of the tea plants, theanine, glutamine, catechin, and gallocatechin were uniquely dependent on the age of tea plants, demonstrating a difference of theanine metabolism between young and old tea plants. These results suggest that leaves from 25-year-old tea plants would still be worthy as a functional ingredient for the production in the food or cosmetic industry rather than quality-enhanced tea infusions for human consumption.

With the increase of tea (Camellia sinensis) consumption, its chemical or metabolite compositions play a crucial role in the determination of tea quality. In general, metabolite compositions of fresh tea leaves including shoots depend on plucking seasons and tea cultivators. Therefore, choosing a specific plucking time of tea leaves can provide use-specified tea products. Artificial control of tea growing, typically shade treatments, can lead to significant changes of the tea metabolite compositions. However, metabolic characteristics of tea grown under various shade treatment conditions remain unclear. Therefore, the objective of the current study was to explore effects of various shade conditions on metabolite compositions of tea through a 1H NMR-based metabolomics approach. It was noteworthy that the levels of catechins and their derivatives were only influenced at the initial time of shade treatments while most amino acids were upregulated as amounts of shade and periods were increased: that is, the l...

Recently, we selected three tea (Camellia sinensis) cultivars that are rich in taste, epigallocatechin-3-O-gallate (EGCG) and epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3″Me) and then cultivated them through asexual propagation by cutting in the same region. In the present study, proton nuclear magnetic resonance (1H NMR)-based metabolomics was applied to characterize the metabotype and to understand the metabolic mechanism of these tea cultivars including wild type tea. Of the tea leaf metabolite variations, reverse associations of amino acid metabolism with catechin compound metabolism were found in the rich-taste, and EGCG- and EGCG3″Me-rich tea cultivars. Indeed, the metabolism of individual catechin compounds in the EGCG3″Me-rich cultivar differed from those of other tea cultivars. The current study highlights the distinct metabolism of various tea cultivars newly selected for cultivation and the important role of metabolomics in understanding the metabolic mechanism. Thus, comprehensive metabotyping is a useful method to assess and then develop a new plant cultivar.