The nutritional content and value of vegetables vary depending on their edible parts, color, growth stage, and the different parts of the same plant. When purchasing, you can focus your selection based on your specific needs.
Generally, vegetables can be divided into three main categories: stem-and-leaf, root, and fruit. Additionally, there are flowers and gourds. Stem-and-leaf vegetables
include rape, chives, bok choy, spinach, etc., and are rich in vitamin C and carotene. Spinach contains iron, but it also contains oxalic acid, which can hinder the absorption of calcium and iron from food. Therefore, it should be briefly blanched in boiling water before cooking. Root vegetables
include radishes, carrots, taro, potatoes, sweet potatoes, etc. Radishes are high in vitamin C, carrots contain a large amount of carotene, potatoes and taro are high in starch and calories, and have fewer other nutrients. A common characteristic of root vegetables is their rich dietary fiber. If radishes or carrots are cut into thin slices or strips and left for 1-2 days, their dietary fiber content can increase by about 3 times. Therefore, radish-based foods should be cut and eaten immediately and are not suitable for storage after cutting. Fruit vegetables
include tomatoes, beans, bell peppers, cucumbers, loofah, pumpkin, and eggplant, etc. With the exception of beans, pumpkin, loofah, and eggplant, it is best to eat these vegetables raw to avoid the destruction of vitamins during the cooking process. Tomatoes contain a significant amount of lycopene and vitamin C. Beans, including lentils, peas, and edamame, have a high protein content, with a more complete amino acid profile than grains. They are also higher in calcium, phosphorus, iron, and vitamin B1 compared to other vegetables. Pumpkin is rich in carotene. Peppers are relatively abundant in carotene and vitamin C.
The nutritional content also differs in various parts of the same vegetable plant. For example, the green part of a scallion has a much higher nutritional content than the white part. The vitamin A, B1, and C content in the white part is less than half of that in the green part. In the same celery plant, the dark green leaves contain more vitamins A and C than the pale green stems and stalks. The same is true for bok choy, where the leaves have a higher nutritional content than the stems.
Because the human body requires a "full range" of nutrients, it is impossible to meet this requirement by eating only one type of vegetable. Therefore, only through reasonable and clever pairing,坚持多品种、多颜色 (insisting on a variety of types and colors) can nutritional balance be ensured.