Variation of theanine, phenolic, and methylxanthine compounds in 21 cultivars of Camellia sinensis harvested in different seasons

Abstract

This is the first study to use chemometric methods to differentiate among 21 cultivars of Camellia sinensis from China and between leaves harvested at different times of the year using 30 compounds implicated in the taste and quality of tea. Unique patterns of catechin derivatives were observed among cultivars and across harvest seasons. C. sinensis var. pubilimba (You 510) differed from the cultivars of C. sinensis var. sinensis, with higher levels of theobromine, (+)-catechin, gallocatechin, gallocatechin gallate and theasinensin B, and lower levels of (-)-epicatechin, (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG), respectively. Three cultivars of C. sinensis var. sinensis, Fuyun 7, Qiancha 7 and Zijuan contained significantly more caffeoylquinic acids than others cultivars. A Linear Discriminant Analysis model based on the abundance of 12 compounds was able to discriminate amongst all 21 tea cultivars. Harvest time impacted the abundance of EGC, theanine and afzelechin gallate.

Seasonal Theanine Accumulation and Related Gene Expression in the Roots and Leaf Buds of Tea Plants (Camellia Sinensis L.)

“…These studies indicated that theanine accumulation was dynamically regulated by seasons (Konishi and Takahashi, 1969; Takeo, 1981; Janet et al, 2015), light (Yang et al, 2012; Deng et al, 2013; Chen et al, 2017; Ji et al, 2018; Sano et al, 2018), nutrient levels (Takeo, 1981; Ruan et al, 2007; Ruan et al, 2010; Ruan et al, 2012; Huang et al, 2018; Kc et al, 2018; Zhu et al, 2019), hormones (Li et al, 2016a), developmental stages (Feldheim et al, 1986; Li et al, 2016b; Liu et al, 2017), and stress (Deng et al, 2012; Wang et al, 2016). Theanine accumulation is also highly tissue-and cultivar-dependent (Fang et al, 2017; Liu et al, 2017; Chen et al, 2018a; Chen et al, 2018b). Theanine accumulation, therefore, is dynamic and highly regulated.…”

Integrated transcriptomics and metabolomics analysis of catechins, caffeine and theanine biosynthesis in tea plant (Camellia sinensis) over the course of seasons

“…The story of tea starts in China in 2737 BC. China remians the largest tea producer with an output of 1.9 million tons annually [5,6] with more than 100 officially approved tea cultivars in 15 provinces [7,8]. Xinyang maojian tea is one of the Chinese traditional famous teas with a specific flavor.…”

“…Xinyang maojian tea is one of the Chinese traditional famous teas with a specific flavor. Some evidence indicates that these specific flavors are highly related to the abundance of specific secondary metabolites such as polyphenols, theanine, caffeine, vitamins, volatile oils, polysaccharides, and minerals [2,3,6]. Among these metabolites, polyphenols, caffeine, and theanine are usually considered as distinctive functional compounds, which play key roles in the formation of special taste, as well as nutritional and medicinal properties [6,[9][10][11].…”

“…It has been showed that the amounts of catechins, caffeine, and theanine are determined by factors such as tea varieties [6], altitudes [20], rolling methods and processing stages [16]. However, the information concerning the season changes of these compounds is underestimated.…”

Using stable isotope signatures to delineate the geographic point‐of‐origin of Keemun black tea

“…This range might be due to genetic effects on nitrogen metabolism in the different tea cultivars. 27,28 Since 13 C and 15 N values are expected to be influenced by genetic factors, this data could provide some useful information for future sampling strategies and for discussions on determining the geographic origins of teas by IRMS. In some plant-derived foods, like potato, the variety does impact the stable isotope composition, 5 but it is not a significant (P > 0.05) factor in pistachios.…”