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. | Turkish Journal of Agriculture and Forestry Research Article Turk J Agric For (2018) 42: 383-392 © TÜBİTAK doi: Quality constituents of high amino acid content tea cultivars with various leaf colors Lin-long MA , Yan-li LIU , Dan CAO , Zi-ming GONG , Xiao-fang JIN* Fruit and Tea Research Institute, Hubei Academy of Agricultural Sciences, Wuhan, . China Received: Accepted/Published Online: Final Version: 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. Key words: HPLC, green tea, high amino acid content, bioactive profile, biosynthesis 1. Introduction Tea is one of the most widely consumed nonalcoholic beverages worldwide because its water-soluble components have important health benefits (Khan and Mukhtar, 2013; Fang et al., 2014). The quality of processed tea is mainly determined by its metabolic constituents such as free amino acids, catechins, purine alkaloids (caffeine), and pigment (chlorophylls .
