不同生长发育阶段叶下珠中硝酸盐·亚硝酸盐及维生素C含量研究

Research on Contents of Nitrate,Nitrite and Vitamin C in Leaves at Different Growth Stages of Phyllanthus urinaris L.

[目的]为人们安全食用叶下珠提供科学依据。[方法]利用分光光度计法对不同生长发育阶段叶下珠中硝酸盐、亚硝酸盐和维生素C的含量进行测定。[结果]除初花期以外,叶下珠的硝酸盐含量低于轻度污染水平(432 mg/kg鲜重),亚硝酸盐含量低于无公害蔬菜亚硝酸盐含量的限量标准(≤4.0 mg/kg鲜重),初花期叶下珠硝酸盐含量高于432 mg/kg且低于785 mg/kg,属于中度污染水平,亚硝酸盐含量低于无公害蔬菜亚硝酸盐含量的限量标准。各期的叶下珠中维生素C的含量都高于50 mg/100 g鲜重,属于高维生素C含量的野菜。[结论]根据国内外现行硝酸盐、亚硝酸盐污染标准,除初花期以外的各生长发育阶段属于一级野菜,可以安全食用。初花期的叶下珠属二级蔬菜范围,不宜生食,煮熟或盐渍可安全食用。

[ Objective ] The aim was to provide scientific basis for using wild vegetable safely. [ Method] The contents of nitrate, nitrite and vitamin C in edible parts of PhyUanthus urinaris L. at different growth stages were determined by spectrophotometry. [ Result ] The nitrate content is lower than light pollution level （432 mg/kg fresh weight）, nitrite content is lower than the limit standard content of green vegetable （ ≤ 4.0 mg/kg）, except primary flowering. Nitrate content is higher than 432 mg/kg,but lower than 785 mg/kg, belonging to medium pollution level, nitrite content is lower than the limit standard content of green vegetable at primary flowering. Vitamin C content is higher than 50 mg/kg at each stage, belonging to high content vitamin C wild vegetable. [ Conclusion] According to the evaluation standards for nitrate and nitrite pollution at home and aboard, its quality was discussed as follows： except the primary flowering stage, the wild vegetable belongs to the first class vegetables and can be eaten safely. At the primary flowing stage, it belongs to the second class vegetable and can be eaten after salted or cooked.