Many netizens know that in order to prevent pests and diseases, most vegetables are sprayed with pesticides. So, is there a difference in pesticide distribution on the same vegetable plant? Which part has the most pesticides? Let's see what the experts have to say.
The stalks and stems of vegetables have the most pesticide residues
Liu Zhenfang, a professor in the Department of Health and Nutrition at Peking University Health Science Center, pointed out that the stalks and stems of vegetables are the parts with the most pesticide residues. For example, the stalks near the root of Chinese cabbage and the indented part connected to the stem of bell peppers have more pesticides than other parts. It's best to discard them when eating.
Why do pesticides on vegetables always accumulate in these parts? Researchers from the National Engineering Research Center for Vegetables pointed out that this is related to the way vegetables grow and the method of pesticide application.
Take Chinese cabbage as an example. First, during spraying, due to gravity, pesticides flow down along the leaves and stalks, accumulating under the main stalk. Therefore, the stalks will have more pesticides.
Second, because the stalks are close to the ground, the chance of pesticides being reduced or decomposed by wind and sun is smaller, so the pesticide residues on the stalks are more persistent. However, for vegetables without obvious stalks, such as crown daisy stalks or flowering Chinese cabbage, this is not an issue.
As for bell peppers, although they hang from the plant, they still follow this rule. Experts explain that because bell pepper plants are relatively short, pesticides are often sprayed from top to bottom, causing many pesticides to accumulate at the stem. Therefore, vegetables with uneven stems, like bell peppers, have this problem, while others like cowpeas and cucumbers do not.
Therefore, when we eat vegetables, it's best to cut off the stalks near the ground. For vegetables like bell peppers, you should remove the stem before eating.
Don't迷信 "wormholes" in vegetables
In order to eat vegetables without pesticide residues, many consumers like to buy leafy greens and cowpeas with wormholes, believing that such vegetables must not have been sprayed with pesticides.
He Jiguo, head of the Department of Nutrition and Food Safety at the College of Food Science and Nutritional Engineering at China Agricultural University, advises against being keen on buying vegetables with wormholes. The presence of wormholes is not a standard for measuring whether pesticides have been used. Because after consumers buy vegetables with wormholes, they basically never find worms in the food. Farmers do not manually remove pests, so it is generally the case that after a pest infestation, the pests are eliminated by pesticides.
He pointed out that for vegetables with wormholes, adult insects are killed by pesticides, while for those without, larvae or eggs are killed. It should also be noted that the resistance of adult insects is obviously greater than that of larvae, so the amount of pesticide used might be higher. Moreover, the appearance of adult insects is definitely later than that of larvae, so the time of pesticide application for vegetables with wormholes is closer to the harvest date, meaning the pesticides decompose less and have higher residues. In summary, consumers should not blindly believe the traditional notion that "wormholes mean no pesticides."