1. In a vegetable, the outer leaves contain more vitamin C than the inner leaves, and the leaves contain more than the stems. Therefore, try to discard as few of the outer leaves and leafy parts as possible;
2. Wash vegetables before cutting them;
3. Cut and cook vegetables immediately; do not soak them in water for a long time, as this will cause soluble vitamins and inorganic salts in the vegetables to dissolve into the water and be lost;
4. When cooking vegetables, adding a little vinegar appropriately can reduce the loss of vitamin C. This is because vitamin C is easily destroyed in an alkaline environment but is relatively stable in an acidic environment;
5. When stewing or boiling vegetables, add the vegetables to the boiling water. This can reduce the loss of vitamins and also minimize the change in the vegetable's original color.