|Title||Stimulated biosynthesis of delphinidin-related anthocyanins in tea shoots reducing the quality of green tea in summer|
|Author(s)||Zhang, Qunfeng; Hu, Jianhui; Liu, Meiya; Shi, Yuanzhi; Vos, C.H. de; Ruan, Jianyun|
|Source||Journal of the Science of Food and Agriculture 100 (2020)4. - ISSN 0022-5142 - p. 1505 - 1514.|
|Department(s)||BIOS Applied Metabolic Systems|
|Publication type||Refereed Article in a scientific journal|
|Abstract||BACKGROUND: Greater proportions of purple tea buds and leaves usually appear in the summer, which seriously affects the
color and taste quality of green tea products, yet the metabolism of purple tea shoots in summer remains unclear. Here, the metabolomic profiles and gene expression of related flavonoid metabolic pathways in the purple and normal green shoots of ‘Longjing 43’, and the quality of green teamade with these two phenotypes, were analyzed and compared.
RESULTS: Differential metabolites identified using high-performance liquid chromatography–Orbitrap/mass spectrometry indicated that anthocyanin biosynthesis in purple leaves was enriched, with higher levels of anthocyanidins
(delphinidin-hexose-coumaroyl showed the greatest increase), proanthocyanidins (oligomers of catechins) and kaempferol
glycoside. Expression patterns of the genes ANR, ANS, FLS, LAR, C4H, PAL, CHI, CHS and DFR revealed that the metabolism of
anthocyanin is positively regulated by high temperature and/or light levels in summer. Gas chromatography–mass spectrometry
results showed that, in purple tea shoots, themetabolism of carbohydrates was enriched whereas that of amino acids was
diminished, while their mannose, fructose, D-galactose, sorbose and D-glucose contents were more than double those found in green leaves. A sensory evaluation confirmed that a greater quantity of purple shoots had a greater negative impact on green tea quality because of a bitter taste and dark color (leaves and infusions were tested).
CONCLUSIONS: These results highlight the need for and possibility of improving commercial tea quality via cultivation that
controls the temperature or light of tea gardens during the summer.
© 2019 Society of Chemical Industry
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