some people like to put some alkali in stir-fried hearts, so that the fried hearts can really make their colors fresh. However, this method is not desirable, because the cabbage is rich in vitamins, among which vitamin C is the main one, and vitamin C fails to oxidize in alkaline solution. Therefore, it is not appropriate to put alkali in stir-frying heart, and the method of quick frying should be adopted, which can reduce the loss of vitamin C and maintain its due value.

2. It is not advisable to put vinegar in fried carrots.

Carrots contain a lot of carotene, which can be turned into vitamin A after being ingested in the digestive organs of the human body. Vitamin A can maintain the health of eyes and skin. People with rough skin and night blindness are short of vitamin A.. But be careful not to stir-fry carrots with vinegar, or carrots will be destroyed.

3. It's not suitable for boiling vegetables in cold water.

After vegetables are heated in water, the cell membrane is destroyed and oxidase is produced, which has a strong destructive effect on vitamin C. However, this enzyme is not tolerant to high temperature, and its activity is very strong at 65 degrees Celsius, and it will be destroyed when it is above 85 degrees Celsius. When cooking vegetables, if the water is cold, the pot will be cooked. When the water temperature is 3-65 degrees Celsius, oxidase will be released in large quantities, and vitamins will be destroyed. If it is boiled in boiling water, the oxidase will lose its activity immediately, so that most of the vitamin C in vegetables can be maintained. In addition, if you put vegetables in the boiling water, it will prolong the boiling time, so that the nutrients in vegetables will be dissolved in water in large quantities, and the vegetables will lose their crisp texture and become soft and rotten. When the blanching time is long, the chlorophyll in vegetables will decompose rapidly, losing its original green color and affecting the quality of vegetables. Therefore, vegetable blanching should be done when the water is boiling.