How to wash fruits and vegetables contaminated with pesticides
Professor He Jiguo from the College of Food Science at China Agricultural University believes that strictly speaking, different fruits and vegetables should be washed differently.
How to wash fruits and vegetables contaminated with pesticides
Professor Li Li, a doctoral supervisor from the College of Food Science at China Agricultural University, said that generally speaking, fruits and vegetables that are prone to pests and difficult to control after being infested are often varieties with more serious pesticide contamination. For example, among fruits, apples, pears, plums, grapes, strawberries, watermelons, oranges, and bananas have relatively high pesticide residues, while shell fruits such as lychees and longans have less contamination. Vegetables with heavier pollution include leafy and delicate vegetables, such as bok choy, green vegetables, chicken feather vegetables, chives, spinach, and rapeseed. In contrast, root vegetables, gourds, and fruit vegetables (such as potatoes, pumpkins, cucumbers, bitter melon, tomatoes, butternut squash, and onions) are relatively less contaminated by pesticides, and these vegetables also have higher nutritional content.
How to wash fruits and vegetables
Effective washing methods for fruits and vegetables can also reduce pesticide contamination.
Professor He Jiguo from the College of Food Science at China Agricultural University believes that strictly speaking, the washing methods for different fruits and vegetables are different. For example, when washing eggplants, green peppers, and fruits, people are accustomed to gently rubbing their surfaces with their hands. Although this can remove some pesticides, it also removes the natural wax on their surface. If they are then soaked in water for a long time, it is easy for residual pesticides to seep into the vegetable or fruit flesh. Therefore, for fruits and vegetables like eggplants, apples, grapes, and strawberries, it is best to rinse them under running water, supplemented by special detergents for pesticide removal. For leafy vegetables, because the leaves are thin and inconvenient to wash by hand, the wax on their surface is not removed, which acts as a barrier, making it difficult for pesticides to seep in. Therefore, directly soaking leafy vegetables can reduce pesticide residues.
Regarding the saying, "Buy vegetables with worm holes for no pesticides," Professor Li believes there is no scientific basis. Because it is difficult for farmers to kill all pests at the same time when spraying pesticides, over time, pests will develop resistance. When farmers spray pesticides again, they will escape and then "come back to kill." Therefore, vegetables with worm holes are not necessarily free of pesticide residues. Moreover, the表皮 of vegetables has a layer of wax that can prevent pests and toxic substances from causing harm. Once the表皮 of the vegetable is damaged, various bacteria and other pathogenic microorganisms will take advantage of the situation, which is not good for human health.
As for cherry tomatoes and large tomatoes, Professor Li humorously said that cherry tomatoes were produced by foreigners for the sake of table manners. If we don't care about table manners at home, it's best to choose large tomatoes. Because for the same weight, cherry tomatoes have a much larger surface area than large tomatoes, so the area exposed to pesticide spraying is also larger. Moreover, for the same weight of fruit flesh, cherry tomatoes have a much higher proportion of peel than large tomatoes, so their nutritional value is not as high as that of large tomatoes.