臺灣中部臺灣山茶（Camellia formosensis）兒茶素及咖啡因含量分析

Analysis of catechins and caffeine content of Camellia formosensis in Central Taiwan

臺灣山茶（Camellia formosesis）為臺灣特有的山茶科植物，零星分布於臺灣中部以南的中低海拔山區，並在臺灣中部形成其天然分布的最北邊界，具有穩定的野外族群。本研究選定南投縣仁愛鄉眉原山、鹿谷鄉鳳凰山、鹿谷鄉樟湖山及信義鄉雙龍的臺灣山茶族群，進行兒茶素和咖啡因含量分析。研究結果顯示，鳳凰山地區的總兒茶素（TC）含量最高，平均為103.70 mg.g-1，其中主要兒茶素成分包括表沒食子兒茶酚沒食子酸（EGCG）、表沒食子兒茶酚（EGC）和沒食子兒茶素（GC），其中又以EGCG含量最高，平均達44.81 mg.g-1。咖啡因平均含量為25.68 mg.g-1，以樟湖山地區最高，雙龍地區最低。此外，不同個體的臺灣山茶在酯型、非酯型兒茶素含量與兒茶素品質指數、苦澀味指數方面具有明顯差異。利用二階段集群分析將中部地區臺灣山茶分為高總兒茶素型、低總兒茶素型、高EGCG型和低EGCG型等四大類型，顯示臺灣中部地區的臺灣山茶具有高度的基因多樣性。本研究結果對於臺灣山茶的優良品系選育和保育提供了重要參考依據。

Camellia formosensis, endemic to Taiwan, is a unique species of the Theaceae family, sparsely distributed in the mid to low-altitude mountainous regions of central to southern Taiwan, forming its natural northern boundary in central Taiwan. It maintains stable populations in the wild. This study selected populations of Camellia formosensis from Meiyuan Mountain in Renai Township, Fenghuang Mountain and Zhanghu Mountain in Lugu Township, and Shuanglong in Xinyi Township, Nantou County, Taiwan, for analysis of catechin and caffeine content. The results showed that the total catechin (TC) content was highest in the Fenghuang Mountain area, averaging 103.70 mg.g-1, with major catechin components including epigallocatechin gallate (EGCG), epigallocatechin (EGC), and gallocatechin (GC). Among them, EGCG content was the highest, averaging 44.81 mg.g-1. The average caffeine content was 25.68 mg.g- 1, with the highest in the Zhanghu Mountain area and the lowest in the Shuanglong area. Furthermore, differences were observed among different individuals of Camellia formosensis in terms of esterified and non-esterified catechin contents, as well as catechin quality and bitterness indices. Using two-stage cluster analysis, Camellia formosensis in central Taiwan was classified into four major types: high total catechin type, low total catechin type, high EGCG type, and low EGCG type, indicating a high degree of genetic diversity. These findings provide important references for the breeding and conservation of superior strains of Camellia formosensis.