Authors: LIN-LONG MA, YAN-LI LIU, DAN CAO, ZI-MING GONG, XIAO-FANG JIN
Abstract: Green tea made from high amino acid content (HAAC) tea cultivars with different leaf colors exhibits many similar characteristics, such as slight bitterness, a rich aroma, and a refreshing and velvety taste. To determine differences in the key constituents of five HAAC tea cultivars with various leaf colors, the cultivars quality constituents were systematically analyzed and compared with that of a normal green tea cultivar. High theanine (Thea) content and the synthesis of Thea precursors are extremely important determinants of the character of these HAAC tea cultivars. The levels of most catechins, carotenoids, and chlorophylls in the HAAC tea cultivars were significantly lower than those in the normal tea cultivar, as was that of caffeine. The present study suggests that the inhibition of catechins (particularly epicatechins; ECs), chlorophylls, carotenoids, and caffeine biosyntheses in HAAC tea cultivars directs the metabolic network toward amino acid biosynthesis, particularly Thea biosynthesis.
Keywords: HPLC, green tea, high amino acid content, bioactive profile, biosynthesis
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