Main Pollutants in Vegetables, Whether Vegetables with Wormholes Are Safe, and How to Remove Pesticide Residues
In the modern era of industrialization and technology, people's lives are becoming more and more convenient, but the food safety problems that come with it are also constantly sounding alarm bells.So what are the main pollutants in edible vegetables? Are those with wormholes safe? What methods are there for removing pesticide residues?
1. What are the main pollutants in edible vegetables?
At present, the main pollutants in vegetables in China are pesticide residues, nitrates, heavy metals and so on. Biological contamination is also beginning to attract attention, but since the vast majority of vegetables consumed in China are eaten cooked, and the cooking process can inactivate microorganisms, the harm of biological contamination to the human body can basically be avoided as long as vegetables are not eaten without heating or are thoroughly washed before eating.
1. Pesticide residues: especially residues of organophosphorus and carbamate pesticides, which currently have the most varieties in production, the largest usage, and are also the most likely to cause severe poisoning reactions. Long-term consumption of substandard vegetables contaminated with pesticides can cause chronic pesticide poisoning.
2. Nitrates: they are easily enriched in vegetables. They themselves are not very toxic, but in the human body they are reduced to nitrites, and nitrites can synthesize carcinogenic nitrosamines, leading to cancer of the digestive system. Studies have shown that the longer cooked vegetables are stored, the more significantly their nitrite content increases, so it is recommended not to eat vegetables that have been stored overnight after cooking.
3. Heavy metals in vegetables mainly come from the discharge of industrial “three wastes” as well as urban garbage, sludge, and fertilizers and pesticides containing heavy metals. Toxic heavy metals mainly refer to cadmium and chromium, and there is also lead pollution caused by automobile exhaust. Although heavy metal pollution generally does not cause acute poisoning reactions, its long-term accumulation will bring potential threats to human health.
2. Are vegetables with wormholes safe?
1. Many people believe that vegetables with wormholes are safer than those with a complete appearance, indicating that no pesticides were used. This is actually a consumer misconception. Whether vegetables have wormholes cannot serve as a sign of whether vegetables are safe.
2. Many wormholes only indicate that there was once a pest infestation; they do not mean that no pesticides were sprayed. If wormholes are left on the leaves when the vegetable is young, the wormholes will instead grow larger as the leaves grow. Sometimes, for vegetables with many wormholes, farmers may actually spray more pesticide in order to kill these pests.
3. Pests also develop pesticide resistance. Once resistance develops, farmers often need to increase the dose for it to be effective. Therefore, whether a vegetable has pesticide residues cannot be judged only by whether it has wormholes.
3. What methods are there for removing pesticide residues on fruits and vegetables?
1. Running water rinsing plus soaking method: the pesticides contaminating vegetables are mainly organophosphorus insecticides, and organophosphorus insecticides are difficult to dissolve in water, so this method can only remove part of the contaminating pesticides. However, washing with water is the basic method for removing other dirt and residual pesticides from vegetables and fruits, and is mainly used for leafy vegetables, such as spinach, daylily, chive flowers, lettuce, bok choy, and so on. Generally, first rinse off the surface dirt repeatedly with water, then soak in clean water for 15 minutes, and then rinse two or three times under running water. Fruit and vegetable cleaning agents can increase the dissolution of pesticides, so a small amount of fruit and vegetable cleaning agent can be added when rinsing.
2. Running water rinsing plus alkaline water soaking method: organophosphorus insecticides decompose rapidly in an alkaline environment, so this method is an effective measure for removing pesticide contamination. It can be used for various vegetables, melons and fruits. The method is to first rinse the surface dirt clean, soak in alkaline water (generally add 5 to 10 grams of alkaline powder to 500 milliliters of water) for 5 to 10 minutes, and then rinse 3 to 5 times with clean water.
3. Peeling method: the amount of pesticides on the surface of vegetables, melons and fruits is relatively high, so peeling is a relatively good method for removing residual pesticides. It can be used for apples, pears, kiwifruit, cucumbers, carrots, winter melon, pumpkin, zucchini, eggplant, radish, and so on.
4. Storage method: during storage, pesticides can slowly decompose over time into substances harmless to the human body. Therefore, for melons, fruits and vegetables that are easy to store, a certain period of storage can reduce pesticide residues. It is suitable for types that do not rot easily, such as pumpkin and winter melon. At the same time, it is recommended not to immediately eat newly picked fruits that have not been peeled.
5. Heating method: as the temperature rises, carbamate insecticides can decompose faster. Therefore, for some vegetables, melons and fruits that are difficult to handle by other methods, heating can remove part of the pesticides. It is often used for celery, spinach, bok choy, cabbage, green peppers, cauliflower, green beans, and so on. First wash the surface dirt clean with clean water, put them into boiling water for 2 to 5 minutes and take them out, then wash them once or twice with clean water.
However, everyone should not worry too much. Many vegetables nowadays are grown with organic fertilizer and so on, and the entire growth process can also be traced back to its source, so buying them is also very good.