Since pesticides are mainly attached to the surface of fruits and vegetables during the spraying process, adopting effective washing and processing methods can reduce pesticide residues and ensure the safety of vegetables for consumption.
Soaking and rubbing with clean water can reduce pesticide residues, and the longer the soaking time, the fewer the pesticide residues. Experiments have shown that soaking vegetables in tap water for 10-60 minutes followed by a light rub can remove 15%-60% of pesticide residues. Soaking with a special fruit and vegetable detergent is more effective for reducing pesticide adhesion. After diluting the detergent with water in a 1:200 ratio and soaking fruits and vegetables, pesticide residues can be reduced by 50%-80% within 10-60 minutes; especially in the first 10 minutes of soaking, the reduction in pesticide residues is very significant, reaching about 50%. Then, after a light rub and rinsing with clean water, pesticide residues can be basically removed.
High-temperature heating can also decompose pesticides, such as blanching with boiling water or stir-frying in oil. Experiments have proven that some heat-resistant vegetables, such as cauliflower, beans, green peppers, and celery, can have their pesticide residues reduced by about 30% after being washed and then blanched in boiling water for a few minutes. After further high-temperature stir-frying, 90% of the pesticides on the vegetables can be removed.
In addition, washing vegetables with rice water and appropriate exposure to sunlight can also help reduce pesticide residues on vegetables. However, it's best to use the first or second batch of rice water for washing, because the surface of the rice contains potassium, so the first or second batch of rice water will be weakly acidic. After that, it starts to become alkaline, and pesticides only lose their toxicity in acidic substances. Sunlight exposure can decompose and break down some pesticides in vegetables. According to measurements, after 5 minutes of sunlight exposure, the residue loss of organochlorine and organomercury pesticides on vegetables can reach about 60%.
Peeling vegetables can also reduce pesticide residues, but it will lead to a loss of vitamins and minerals in the peel. Therefore, the best method for removing pesticides is to first soak fresh fruits and vegetables in a detergent for 10-15 minutes, or in tap water for 30-60 minutes, and then rinse thoroughly with clean water.