As the weather warms up, facing fresh and crisp vegetables, many people choose to eat them raw. In this regard, Tang Xiaowei, an associate researcher at the National Vegetable System Engineering Center, reminds consumers that nutrients in vegetables, such as vitamin C and B vitamins, are easily destroyed by processing and cooking, so eating them raw helps preserve these nutrients. However, not every vegetable is suitable for direct raw consumption. Some vegetables are best blanched in boiling water before eating, while others must be thoroughly cooked.
Vegetables that can be eaten raw after washing include carrots, radishes, tomatoes, cucumbers, bell peppers, and the heart of Chinese cabbage. Tang Xiaowei says that for raw consumption, it's best to choose pollution-free green vegetables or organic vegetables.
Vegetables grown in soilless cultivation can also be eaten raw with confidence. Methods of eating raw include drinking fresh homemade vegetable juices or preparing fresh vegetable salads, with a small amount of vinegar and less salt.
Vegetables that should be blanched before eating fall into the following categories: The first category is cruciferous vegetables, such as broccoli and cauliflower. These nutrient-rich vegetables have a better texture after blanching, and their abundant fiber is also easier to digest. The second category is vegetables high in oxalic acid, such as spinach, bamboo shoots, and water bamboo. Oxalic acid combines with calcium in the intestines to form calcium oxalate, which is difficult to absorb and interferes with the body's calcium absorption. Therefore, they must be blanched in boiling water before making a salad to remove most of the oxalic acid. The third category is mustard vegetables, such as turnips. They contain a substance called glucosinolate, which, when hydrolyzed, produces volatile mustard oil that aids digestion and absorption. The fourth category is wild vegetables like purslane. Blanching thoroughly removes dirt and small insects and prevents allergies. Additionally, for vegetables like lettuce and water chestnuts, it is best to peel, wash, and blanch them in boiling water before eating raw for better hygiene, without affecting the taste and nutritional content.
Of course, not all vegetables can be used in salads. Starchy vegetables, such as potatoes, taro, and Chinese yam, must be cooked, otherwise the starch granules will not break down, and the human body cannot digest them. Kidney beans contain a large amount of saponins and hemagglutinins. If not cooked thoroughly, they can cause poisoning. Kidney beans should be cooked for a long time, not a short one, until they are fully cooked and discolored before they can be safely eaten. Bean sprouts are best stir-fried. Even if eaten in a salad, they must be cooked first.
"Eating a combination of raw and cooked vegetables is more beneficial to the body," Tang Xiaowei said. For example, there are many varieties of radishes. For eating raw, those with more juice and less spiciness are better, but they are considered cooling foods, so people with yin deficiency should eat them cooked. The nutrients absorbed from some foods can be different when eaten raw versus cooked. For instance, tomatoes contain lycopene, which can reduce the risk of prostate and liver cancer. To absorb lycopene, tomatoes should be eaten cooked. However, if you want to get vitamin C, eating them raw is more effective because vitamin C is easily lost during cooking.