Kale has been a popular vegetable for some time and can often be found in products such as fat-reducing meals and fruit and vegetable juices. According to merchants, kale is low in calories and rich in dietary fiber and vitamins, making it a healthy food.
But recently, the topics of "kale with excessive pesticide residues" and "cannot be grown without pesticides" have attracted much attention on social media. Some bloggers posted that "kale is a green belt plant. Eating kale is equivalent to eating the green belt." Is this true?
"The dirtiest fruits and vegetables" have limitations
The recent popularity of kale comes from the "Dirtiest Vegetables and Fruits List" released by a foreign non-governmental organization. The list shows that kale is second only to spinach in terms of pesticide residues, ranking second on the “Dirtiest Fruits and Vegetables List.” However, the accuracy of the list is controversial in the industry.
Xie Zhujie, director of the Science and Technology Agricultural Promotion Office of the Shanghai Academy of Agricultural Sciences and a researcher at the National Vegetable Improvement Shanghai Branch, believes that the list results are "for reference only" and can only show that some agricultural products have used a variety of pesticides in their cultivation, but cannot prove that certain agricultural products must have problems. "The list itself is from a non-governmental organization, not an official organization, and the accuracy of the data needs to be verified. At the same time, the ranking of the list is based on the 'number of detected pesticide residue species' rather than 'exceeding the standard amount of pesticide residues'. 'Detected' does not mean 'exceeding the standard', and toxicity cannot be discussed apart from the dose."
Some bloggers confuse edible kale with ornamental kale and conclude that "green belt plants are seriously polluted, so kale cannot be eaten", which is also misleading.
Xie Zhujie introduced that edible kale and ornamental kale are different breeding results of the same species in horticulture. Although they are "close relatives", their breeding directions and planting standards are completely different. Most edible kale is dark green. When breeding, attention should be paid to taste and nutritional value. All aspects of planting and sales must comply with the country's requirements for agricultural products. When breeding kale for ornamental use, more attention is paid to leaf color, shape, environmental adaptability, etc. There is no need to consider taste. Its pest control and pesticide use follow flower care standards.
Can be grown without pesticides
The statement spread on social platforms that “kale cannot be grown without pesticides” is not consistent with the actual situation.
Xie Zhujie pointed out that the natural flavor of kale attracts pests such as cabbage caterpillars, coupled with the expanded leaves and long growth cycle, it is indeed more "insect-attracting". But chemical pesticides are not the only way to control pests. Shanghai is located in the middle and lower reaches of the Yangtze River and is a dominant production area for overwintering open-field vegetables. Winter climate conditions are very friendly to cool vegetables such as kale, and the level of insect pests is much lower than in summer and autumn. Therefore, overwintering kale can be achieved with minimal use of pesticides.
Faced with the situation where leaf-eating pests are more active in high-temperature and high-humidity environments, there are also relatively mature physical and biological control methods. Mr. Chen, the person in charge of a kale planting base in Yunnan, said: "We do not use chemical pesticides, but use physical isolation nets, botanical pesticides, microbial inoculants, etc. to control pests and diseases." Mr. Chen emphasized, "The kale at our base has undergone more than 800 pesticide residue tests by third-party organizations, and all results are 'not detected.' In China, many planting bases are similar to ours and can use physical and biological insect control technologies to minimize pesticide residues."
Xie Zhujie also said that even chemical agents and compliant pesticides have the characteristics of high efficiency, low toxicity, and easy degradation, and highly toxic pesticides have long been banned. Moreover, according to national requirements, there is a statutory "safety interval" before agricultural products are put on the market, that is, a certain number of days must elapse between the last application of pesticides and the harvesting of agricultural products to ensure that pesticide residues are reduced to within national safety standards during harvesting.
Front-line growers and agricultural experts also corrected a misunderstanding: "The presence of insect holes in fruits and vegetables proves that no pesticides have been sprayed" is inaccurate. Insect bite marks can only prove the occurrence of insect infestation, and have no necessary relationship with whether pesticides are used or whether pesticide residues exceed standards. For production bases that use physical isolation methods such as insect-proof nets and insect traps, it is entirely feasible for fruits and vegetables to keep their appearance intact and clean without spraying pesticides.
It's healthier to eat this way
According to industry insiders, the food safety risk of edible kale sold through formal channels is not high.
Some consumers are concerned about the safety of kale because of its special leaf shape: the leaves are stacked and curled, with many wrinkles and ravines, and medicinal liquids and dust can easily be hidden in the gaps. Xie Zhujie suggested that when cleaning kale, you can tear off the leaves one by one, remove the outer layer of damaged old leaves, and then gently rub the crevices under flowing water. After that, soak the leaves in clean water or low-concentration baking soda water for about 5 minutes, rinse and drain again.
Registered dietitian Xue Qingxin said that kale is rich in dietary fiber, so its taste is slightly rough; the glucosinolates and its hydrolyzates contained in it have a certain bitterness and spicy flavor, which will also affect the taste. Glucosinolates decompose when heated, and if you blanch kale before eating, it can also reduce the bitter taste.
Xie Zhujie also reminded that although kale is rich in dietary fiber, vitamins, trace minerals and other nutrients, there is no need to deify it as a "super vegetable". As the "cousins" of kale, vegetables such as broccoli and kale, which also belong to the genus Brassica of the Brassicaceae family, have low calories and equally high nutritional value. They contain radishin, which has strong antioxidant capacity in vegetables, and have both taste and satiety. Therefore, whether it is for fat loss or balanced nutrition, you don’t have to eat kale every time. You can eat different vegetables alternately and maintain a diversified diet.
(Liberation Daily reporter Ren Chong)
