存放时间及存放温度对蔬菜亚硝酸盐含量的影响

目的研究不同存放时间及存放温度对生、熟蔬菜亚硝酸盐含量的影响,为减少亚硝酸盐危害提供依据。方法用格里斯试剂比色法测定生、熟蔬菜室温（25～29℃）和冰箱（4℃）存放温度下,随存放时间亚硝酸盐含量的变化。结果生大白菜存放时间超过24 h,亚硝酸盐含量显著性升高（P〈0.05）;冰箱存放比室温存放延缓亚硝酸盐升高（P〈0.05）;生空心菜存放24 h亚硝酸盐含量显著性下降（P〈0.05）,超过24 h逐渐升高;熟大白菜、熟包菜隔顿（6 h）亚硝酸盐含量下降,隔夜（12 h）亚硝酸盐含量升高。结论生蔬菜存放时间不超过24 h,熟蔬菜即熟即食有助于减轻亚硝酸盐危害。

Effect of Storage Time and Storage Temperature on Nitrite Amount in Vegetable

Objective] To study the effect of different storage time and storage temperature on nitrite amount in cooked and fresh vegetable, and provide evidence for reducing nitrite hazards. Methods] The nitrite amount changes with time in fresh and cooked vegetable was determined under room temperature （25 - 29 ℃ ） and Refrigerator storage temperature （4 ℃ ） by Griess method. Resuits] The nitrite amount of fresh Chinese Cabbage increased significantly when storage time exceeded 24h （ P 〈 0.05 ）. Compared with room storage, refrigerator storage can delay nitrite amount increasing（ P 〈 0.05）. The nitrite amount of fresh water spinach decreased significantly within 24h storage time and increased subsequently （ P 〈 0.05 ）. The nitrite amount of cooked Chinese cabbage decreased after a meal （6 h）, while increased overnight （ 12 h）. Conclusion] The storage time of fresh vegetable should not exceed 24h. The harm of the nitrite would be reduced if we eat the cooked vegetable immediately.