Besides pesticides, nitrates are also a concerning substance in vegetables. After entering the human body, they are reduced to nitrites, which can hinder the oxygen-carrying function of red blood cells, causing fatigue when consumed in excess. Additionally, nitrites can react with protein breakdown products under acidic conditions, easily forming nitrosamine carcinogens. How to remove nitrates from vegetable leaves?
Generally, leafy vegetables are the crops most likely to retain nitrates, and their nitrate content is significantly higher than that of root and tuber crops as well as melons and fruits (such as bok choy, kale, and amaranth).
To reduce nitrates, you can soak leafy vegetables in warm water for 10 minutes (using about 6-10 liters of water per 500g of vegetables, with the water temperature maintained at 43°C-50°C), and then rinse them under running water. Research has confirmed that 50°C warm water will not destroy the vitamin C and other vitamins in the vegetables. The Taipei City Department of Health once conducted an experiment and found that soaking leafy vegetables in warm water for 10 minutes can remove over 50% of the nitrates, whereas washing with cold water alone only reduces them by 10%-15%.