Category 1: Cruciferous Vegetables
Cruciferous vegetables like broccoli and cauliflower are more palatable after being blanched, and their rich fiber content is also easier to digest.
Category 2: Vegetables High in Oxalic Acid
Vegetables high in oxalic acid, such as spinach, bamboo shoots, and water bamboo, contain oxalic acid that 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 being served cold to remove most of the oxalic acid.
Category 3: Mustard Greens
Mustard greens, such as turnips, contain a substance called glucosinolates. When hydrolyzed, these produce volatile mustard oil, which aids in digestion and absorption.
Category 4: Wild Vegetables like Purslane
Wild vegetables like purslane should be blanched to thoroughly remove dust and small insects, preventing allergic reactions.
In addition, it is best to peel, wash, and blanch lettuce, water chestnuts, and other vegetables in boiling water before eating them raw. This is more hygienic and does not affect the taste or nutritional content.
Of course, not all vegetables are suitable for cold dishes. Starchy vegetables like potatoes, taro, and Chinese yam must be cooked thoroughly; otherwise, their starch granules will not break down, making them indigestible. Kidney beans contain large amounts of saponins and lectins. If not cooked thoroughly, they can cause food 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 are best stir-fried, and even if served cold, they must be cooked first. Eating both raw and cooked is more beneficial for the body.
Fresh wood ear mushrooms and fresh daylilies contain toxins and cannot be eaten directly. When using dried wood ear mushrooms, it is best to soak them in warm water before cooking. Any parts that remain tightly curled after soaking should not be eaten. Dried daylilies are better rehydrated in cold water.
A combination of raw and cooked vegetables is more beneficial for the body. For example, there are many varieties of radish. Those with lots of juice and less spiciness are better for eating raw. However, radishes are considered cooling foods, so people with a yin-deficient constitution are better off cooking them. Furthermore, the nutrients obtained from some foods differ when eaten raw versus cooked. For instance, tomatoes contain lycopene, which can reduce the risk of prostate and liver cancer. To effectively absorb lycopene, tomatoes should be eaten cooked. However, if you want to get more Vitamin C, eating them raw is more effective because Vitamin C is easily lost during cooking.