为快速准确检测荔枝中的多酚,选择白糖罂、白腊、糯米糍3个品种,分别提取、测定其不同部位多酚含量;测定条件是:C18色谱柱,检测波长280 nm,柱温42℃,进样量10μL,3%乙酸水溶液与乙腈梯度洗脱。结果表明:以丙酮为溶剂提取效果最好;多酚总量为白糖罂(662.51 mg/kg)>白腊(442.20)>糯米糍(264.36 mg/kg);在所测9种多酚中,表儿茶素含量最高,依次为394.07、242.45、168.79 mg/kg。3种荔枝果肉中多酚总量依次为3.41、5.78、3.00 mg/kg,果皮中多酚总量依次为469.89、155.96、137.89 mg/kg,果核中多酚总量依次为189.21、283.24、120.69mg/kg。同一品种不同部位是果肉中多酚含量最低,果皮与果核中多酚含量的高低则因品种而异,选取适宜品种或部位是提取荔枝多酚的关键。

In order to investigate the functional components in Lychees(Litchi chinensis Soon),Methanol,ethanol,acetone and ethyl acetate were chosen as the extraction solution to compare the polyphenols in different species(Baitang Ying,Baila,Nuomi Ci) and different parts of the fruit.The contents were determined by reversed-phase high performance liquid chromatography with C18 column(150×4.6 mm,5 μm) at 42 ℃ and 280 nm wavelength.The mobile phase was gradient elute using acetonitrile and 3% acetic acid solution.The result showed that total polyphenol contents were 662.51 mg/kg(Baitang Ying),442.20 mg/kg(Baila)and 264.36 mg/kg(Nuomi Ci)respectively;Epicatechin was the highest one in 9 kinds of Polyphenol,and the contents were 394.07 mg/kg,242.45 mg/kg and 168.79 mg/kg,respectively.Polyphenol contents of three Lychee were 3.41 mg/kg,5.78 mg/kg and 3.00 mg/kg in the flesh,469.89 mg/kg,155.96 mg/kg,137.89 mg/kg in the pericarp and 189.21 mg/kg,283.24 mg/kg,120.69mg/kg in the kernel.These results showed that the lowest polyphenol contents in Lychee was in the flesh while the content in pericarp and kernel varied by the spices.Therefore,choosing the appropriate species or parts of the lychees was the key in polyphenol extracting.