Faculty of Agriculture, Shizuoka University, Shizuoka, Shizuoka, Japan.
Tea Research Division of NARO Institute of Fruit and Tea Science (NIFTS), Makurazaki, Kagoshima, Japan.
PLoS One. 2018 Apr 9;13(4):e0195422. doi: 10.1371/journal.pone.0195422. eCollection 2018.
Endogenous nicotine was confirmed to be present in tea plants (Camellia sinensis L.) by liquid chromatography-tandem mass spectrometry of tea samples from tea-producing regions in six Asian countries. All samples contained nicotine (0.011-0.694 μg g-1 dry weight). Nicotine contents remained constant during manufacturing of green, oolong and black teas, implying that nicotine is stable against heating, drying, enzymatic oxidation and mechanical damage during processing. Flower buds and seeds of cultivar Yabukita also contained nicotine (0.030-0.041 μg g-1 dry weight). A comparison of two cultivars revealed that higher nicotine contents were found in the black tea cultivar Benifuki. All plant parts of hydroponic Yabukita contained nicotine (0.003-0.013 μg g-1 dry weight). Tea cells cultured in B5 medium as well as roots and stems of tea seedlings contained nicotine levels similar to those of new leaves from field-grown plants. Although the levels of endogenous nicotine in tea plants are extremely low and sample contamination cannot be discounted, these levels exceed the maximum acceptable limit in Japan (0.01 μg g-1 dry weight).
通过对来自亚洲六个产茶国的茶叶样本进行液相色谱-串联质谱分析，证实茶叶（Camellia sinensis L.）中存在内源性尼古丁。所有样本均含有尼古丁（0.011-0.694 μg g-1 干重）。在绿茶、乌龙茶和红茶的加工过程中，尼古丁含量保持不变，这表明尼古丁在加工过程中受热、干燥、酶氧化和机械损伤时稳定。芽和种子品种 Yabukita 也含有尼古丁（0.030-0.041 μg g-1 干重）。对两个品种的比较表明，黑茶品种 Benifuki 中的尼古丁含量较高。水培 Yabukita 的所有植物部分均含有尼古丁（0.003-0.013 μg g-1 干重）。在 B5 培养基中培养的茶细胞以及茶苗的根和茎中，尼古丁的含量与田间生长的新叶相似。尽管茶树中内源性尼古丁的含量极低，不能排除样本污染的可能性，但这些水平超过了日本的最高允许限量（0.01 μg g-1 干重）。
