Classification and variation of flavor compounds in traditional tea

本研究的目的是明确阿萨姆品种（Camellia sinensis var. assamica）和中国品种（Camellia sinensis var. sinensis）的各种新鲜茶叶中儿茶素的组成和含量。以茶叶为原料，经丙酮提取、甲基异丁基酮提取、甲醇溶出制备儿茶素。采用高效液相色谱法对10种天然存在的儿茶素进行了分析。阿萨姆邦品种比中国品种含有更多的总儿茶素、EGCg、ECg、eggg、ECgg。阿萨姆邦品种和中国品种的EC含量差异不大。测定了日本、韩国、中国、东南亚、斯里兰卡和印度等地栽培的茶叶品种叶绿体DNA中核酮糖二磷酸羧化酶大亚基（rbcL）基因的核苷酸序列。对扩增的cpDNA产物进行直接测序。报道了中国山茶和阿萨姆山茶的cpDNA中rbcL基因的核苷酸序列。在40号位置（中国的腺嘌呤）和948号位置（中国的鸟嘌呤）进行了两次替换，获得了比对结果。中国山茶和阿萨姆邦山茶rbcL基因核苷酸序列相似度为99.8%。另一方面，irrawadiensis和Camellia taliensis的rbcL的1,307个核苷酸序列与阿萨姆茶相似，只是rbcL基因的627位碱基不同。在C. irrawadiensis和C. taliensis的这个位置，分别观察到胸腺嘧啶和腺嘌呤作为特定的碱基。

The purpose of the present study is to make clear the composition and content of catechins contained in various kinds of fresh tea leaves from Assam variety (Camellia sinensis var. assamica) and the China variety (Camellia sinensis var. sinensis). Catechin fraction was prepared from tea leaves by acetone extraction, methylisobutylketone extraction and methanol dissolution. Ten naturally occurring catechins were analyzed by High Performance Liquid Chromatography (HPLC). The Assam variety contained larger amounts of total catechins, EGCg, ECg, EGCgg, ECgg than the China variety. The Content of EC was not much different between the Assam variety and China varieties.The nucleotide sequences of the ribulose bisphosphate carboxylase large-subunit (rbcL) gene in chloroplast (cp) DNA were determined on the native varieties of tea cultivated in Japan, Korea, China, Southeast Asia, Sri Lanka and India.Direct sequencing of the amplified cpDNA products were carried out. The nucleotide sequences of the rbcL gene in cpDNA of Camellia sinensis var. sinensis (China) and Camellia sinensis var. assamica (Assam) are presented. Alignments were obtained by assuming two substitutions, at position 40 (adenine in the China) and position 948 (guanine in the China). The nucleotide sequences of the rbcL gene in Camellia sinensis var. sinensis (China) and Camellia sinensis var. assamica (Assam) are 99.8% similar. On the other hand, the 1,307 nucleotide sequences of rbcL of Camellia irrawadiensis and Camellia taliensis were similar sequences to Assam tea, with only a different base at position 627 in the rbcL gene. At this position in C. irrawadiensis and C. taliensis, thymine and adenine were observed, respectively, as specific bases.