HPLC quantification of the dihydrochalcones, aspalathin and nothofagin in rooibos tea (Aspalathus linearis) as affected by processing
HPLC quantification of the dihydrochalcones, aspalathin and nothofagin in rooibos tea (Aspalathus linearis) as affected by processing
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DOI：
10.1016/0308-8146(95)00166-2
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发表时间：
1996-04-01
期刊：
影响因子：
8.8
通讯作者：
Joubert, E
中科院分区：
文献类型：
--
作者：
Joubert, E
建立了一种高效液相色谱法测定路易波士茶中C-葡萄糖苷二氢查耳酮、石蒜素和诺托法金的方法。在反相C-18柱上实现了酚级分的梯度分离。通过用热水萃取酚类化合物，然后用乙酸乙酯进行液-液萃取来制备多酚级分。该方法适用于未加工的，部分氧化（未发酵）和发酵的路易波士茶以及在阳光下和受控条件下干燥的茶。CIELAB参数表明，茶叶粉碎后立即发生Aspalathin和Notofagin氧化，导致布朗宁。干燥方法对石蒜素和诺托法金的氧化程度没有影响。(C)1996年Elsevier Science Ltd.
An HPLC method was developed for determination of the C-glucoside dihydrochalcones, aspalathin and nothofagin, in rooibos tea. Gradient separation of the phenolic fraction was achieved on a reversed-phase C-18 column. The polyphenolic fraction was prepared by extraction of the phenolic compounds with hot water, followed by liquid-liquid extraction with ethyl acetate. The method was applied to unprocessed, partially oxidized (unfermented) and fermented rooibos tea as well as tea dried in the sun and under controlled conditions. Aspalathin and nothofagin oxidation occurred as soon as the tea leaves were comminuted which resulted in browning as indicated by CIELAB parameters. The drying method had no effect on the degree of oxidation of aspalathin and nothofagin. (C) 1996 Elsevier Science Ltd.