Before eating vegetables raw, they must be disinfected. Usually, after rinsing with water, the vegetables can be soaked in boiling water for a few minutes; or they can be washed with a disinfectant. Before cooking, hands must be clean and disinfected; raw and cooked foods should be stored separately; vegetables and meat should be washed separately to avoid cross-contamination. At the same time, before serving raw vegetables, you can add seasonings with antibacterial properties such as scallions, ginger, garlic, vinegar, salt, and mustard to achieve a bactericidal effect.
Because the resistance of many pests and weeds to pesticides has generally increased, farmers may use highly toxic and efficient insecticides and herbicides, leading to pesticide residues on vegetables. Therefore, it is best to choose pollution-free green vegetables or organic vegetables for raw consumption. Vegetables grown in soilless cultivation conditions can be eaten raw with confidence.
Vegetables that can be eaten raw after washing include carrots, radishes, tomatoes, the heart of Napa cabbage, cucumbers, and bell peppers. Vegetables that should be blanched before eating, such as spinach and bamboo shoots, contain oxalic acid, which combines with calcium in the intestines to form calcium oxalate, which is difficult to absorb and interferes with the body's absorption of calcium. Therefore, before making a cold salad, they must be blanched in boiling water to remove most of the oxalic acid. For these nutritious vegetables, blanching improves their texture, and the abundant cellulose is easier to digest. For wild vegetables like purslane, blanching can thoroughly remove dust and small insects and prevent allergies.
Starchy vegetables, such as potatoes, taro, and yams, must be cooked, otherwise the starch granules will not break down, and the human body cannot digest them. Kidney beans contain large amounts of saponins and hemagglutinins. If not cooked thoroughly, they can cause poisoning. Kidney beans should be cooked for a long time until they are fully cooked and discolored before they can be safely eaten. Bean sprouts should be stir-fried; even for a cold salad, they must be cooked first.
Cooking vegetables can soften the fiber, which is beneficial for people with weak digestion, indigestion, bloating, and chronic diarrhea. For these people, eating too many raw vegetables may cause diarrhea or bloating, while eating them after cooking can avoid these problems.