Hu Hengying: Many shake-cup drink shops and juice bars in Taiwan Province Province are used to adding juice to milk and soybean milk, claiming that they can absorb rich vitamins in fruits and calcium nutrition in milk and soybean milk at the same time. However, according to the survey of Japan Food and Oil Inspection Association, milk and soybean milk are likely to destroy vitamin C in fruit juice. Homemade fruit and vegetable juice can detoxify and lose weight. Aimei Kuroda, a Japanese cosmetic society and anti-aging professional doctor, pointed out that self-made fruit and vegetable juice is rich in dietary fiber, which can achieve the effect of detoxification and slimming compared with fruit and vegetable juice on the market. As long as 200 ml of fruit and vegetable juice is drunk 30 minutes before meals, citric acid and dietary fiber in fruits and vegetables can effectively inhibit the soaring blood sugar level, avoid inflammatory reactions and toxins in the body, and prevent metabolic syndrome such as hypertension, hyperlipidemia, diabetes and obesity. In addition, because vitamin C not only has the above effects, but also has multiple effects such as beautifying the skin and preventing colds, fruit and vegetable juice mainly containing vitamin C is strongly recommended. Fruits and vegetables rich in vitamin C include green pepper, parsley, celery, lettuce, cabbage, spinach, radish, tomato and strawberry. In order to prevent the loss of vitamin C in fruit and vegetable juice, two taboos that must be avoided are placing at room temperature and heating. Vitamin C can be subdivided into two types, reduced ascorbic acid (AsA) and oxidized ascorbic acid (DAsA). According to the nutrition standard, the lower the residual ascorbic acid (AsA), the better. However, before making fruit juice, L- ascorbic acid oxidase will be produced whether it is cut or planed. This enzyme can increase the ratio of oxidized ascorbic acid (DAsa). Standing at room temperature will promote the production of L- ascorbic acid oxidase. Taking radish juice as an example, after five hours at room temperature, only 27% of reduced ascorbic acid (AsA) remained, and the overall vitamin C content decreased by 26%. Heating can also lead to nutrient loss. Taking green pepper juice as an example, the content of vitamin C decreased by 40% whether it was soaked in hot water at 60℃ or heated by microwave oven. In addition, soybean milk and milk should never be added to fruit and vegetable juice. Milk will increase the ph value, resulting in a significant decrease in the overall vitamin C content. Although the above two kinds will increase the taste, they are harmful to the intake of vitamin C. After the fruit and vegetable juice is prepared, you can add lemon juice with a concentration of 5% before putting it in the refrigerator. Lemon juice can not only prevent the oxidation of reduced ascorbic acid (AsA) to oxidized ascorbic acid (DAsA) and maintain the proportion of reduced ascorbic acid (AsA), but also is rich in vitamin C, killing two birds with one stone. However, Dr. Amy Kuroda also reminded that the juice of fruits and vegetables should be moderate, especially the proportion of fruits should be evaluated to avoid excessive intake of sugar and adverse effects.