1, asparagus (1) asparagus contains antioxidants glutathione and rich in folic acid, antioxidants can directly protect cells from free radical damage, can help and prevent all chronic diseases. (2) The key to buying: green stems and tips are not rotten, thick and tender, and are in full production from April to October each year. (3) What is glutathione: a kind of antioxidant, which can inhibit the activation of carcinogenic substances. 2, bell pepper (yellow, second, green, orange) (1) rich in vitamin C, beta-carotene, effective in preventing atherosclerosis and cancer. For a strong antioxidant, can prevent LDL cholesterol is oxidized, to prevent arterial embolism. (2) Selection and cooking tips: layers with intact shape, shiny and fresh skin, crispy flesh and no shrinkage are good. The green pepper layer is in full production from January to August and December, while other colors of bell peppers are mainly produced in spring. (3) vitamin C will be boiled and steamed or Sichuan hot and lost a large part of the microwave heating, vitamin C loss of only 0-15%, or change to raw food. 3, green cauliflower (1) contains a variety of antioxidants: beta-carotene, glutathione, vitamin C and lutein, antioxidant, anti-cancer and cholesterol. (2) Selection and cooking tips: bright green flower bulbs, dense and tightly packed flower buds, no pests or diseases, no yellowing and no hollow stems are preferred. The peak season is from November to April of the following year. (3) Cooking is best when eaten raw or slightly scalded. Carrots (1) are rich in beta-carotene, which is the highest content of all vegetables and can fight against cancer and protect arteries, and contain soluble fiber and pectin, which can lower cholesterol, prevent cholesterol from being oxidized into harmful substances, increase immune function and prevent infection. (2) Selection and cooking tips: The skin is gorgeous and orange-red, and the shape is straight without lumps or scars. The production period is from December to February and there is no shortage throughout the year. (3) Absorption will be better after heating. 5, onion (1) contains prostaglandin A can diastolic blood vessels, reduce blood pressure and blood viscosity, can prevent coronary heart disease. Rich in hemiphosphoric acid, hemiphosphoric acid is a kind of anti-aging substances, can postpone cellular aging, can be a food of anti-aging. Onion also contains selenium, selenium is one of the components of the antioxidant glutathione, need selenium as a cofactor, in order to play the role of glutathione, eat more onions can be antioxidant. (2) Selection and cooking tips: The production period is from December to February, and the selection is based on smooth and intact skin without sprouting or rotting. (3) Some studies have shown that raw onions can increase HDL cholesterol (good cholesterol), while cooked onions are less effective in increasing HDL cholesterol.