Hönow Ruth, Gu Ke-Liang Reinhold, Hesse Albrecht, Siener Roswitha
Federal Institute for Drugs and Medical Devices, Bonn, Germany.
Urol Res. 2010 Oct;38(5):377-81. doi: 10.1007/s00240-009-0245-x. Epub 2010 Mar 4.
The purpose of the study was to analyse the oxalate content of green tea (Camellia sinensis) depending on origin, quality, time of harvest and preparation. Fifty-two green tea samples were received from different regions of China. The oxalate content of each tea infusion was measured using a validated HPLC-enzyme-reactor method. The soluble oxalate content of green tea ranged from 8.3 to 139.8 mg/l. In samples from known provenances, the highest oxalate concentration was found in green tea from Zhe Jiang. Low grade tea showed a tendency to lower oxalate concentration. Leaves reaped in the autumn when grown to full size yielded more oxalate than small and young leaves reaped in the spring. Modifications in steeping duration of tea leaves had no significant influence on the oxalate content of the beverage. Patients at risk for recurrent stone formation should take into account the oxalate content of green tea.
本研究的目的是分析绿茶（茶树）的草酸盐含量，该含量取决于茶叶的产地、品质、收获时间和制备方法。从中国不同地区收集了52个绿茶样品。使用经过验证的高效液相色谱 - 酶反应器法测量每种茶浸出液中的草酸盐含量。绿茶的可溶性草酸盐含量范围为8.3至139.8毫克/升。在已知产地的样品中，浙江绿茶中的草酸盐浓度最高。低等级茶叶显示出草酸盐浓度较低的趋势。秋季长成全尺寸时采摘的叶子比春季采摘的小而嫩的叶子产生更多的草酸盐。茶叶浸泡时间的改变对饮品中的草酸盐含量没有显著影响。有复发性结石形成风险的患者应考虑绿茶中的草酸盐含量。
