微波消解-原子吸收法测定不同条件下返青箬叶中铜离子的迁移情况

目的探究返青箬叶中的铜离子向不同米处理方法包裹制成的粽子的迁移情况。方法采用的箬叶样品经5%的硫酸铜溶液浸泡处理后制成返青箬叶,包裹经8种不同方法处理的粳糯米后经烧煮、冷却、抽真空、速冻等加工工艺,再由微波消解-原子吸收法测定粽子中的铜离子含量。结果未经硫酸铜浸泡的箬叶包制的白米粽中铜离子含量为1.17mg/kg,此组为对照组,且该组中铜离子的含量作为本次实验铜离子含量的本底值; 8组实验组中,高盐10%组的粽子铜离子含量最高,为20.63 mg/kg; pH 9组的粽子铜离子含量最低为1.69 mg/kg。结论在高盐条件下,返青箬叶中的铜离子不适合与高盐食品直接接触,铜离子会向食品中大量迁移,可能造成铜离子摄入过量。

Determination of copper ion migration in regreen Indocalamus leaves under different conditions by microwave digestion and atomic absorption spectrometry

Objective To explore the migration of copper ions in the regreen Indocalamus leaves to the different rice treatment methods. Methods The samples of Indocalamus leaves were soaked in 5% copper sulfate solution to make regreen Indocalamus leaves. The wrapped Japonica Glutinous rice was treated in 8 different ways and then processed by boiling, cooling, vacuum extraction and quick freezing. Ultimately, the copper ion in zong-zi was determined by microwave digestion and atomic absorption spectrometry (AAS). Results The content of copper ion in zong-zi of white rice wrapped by Indocalamus leaves without copper sulphate immersion was 1.17 mg/kg as the control group, which was used as the background value of copper ion content in this experiment. The content of copper ion in zong-zi in 10% high-salty group was the highest in 8 experimental groups, which was 20.63 mg/kg. The content of copper ion in zong-zi in pH 9 group was the lowest, which was 1.69 mg/kg. Conclusion Copper ions in the regreen Indocalamus leaves are not suitable for directly contact with high-salty food under high salt conditions, and the copper ions can migrate to high-salty food in large quantities, which may lead to excessive intake of copper ions.