1, chemical reaction: the main components of lotus root are purple cabbage and lotus root. Purple cabbage contains a natural pigment called anthocyanin, which will change color in acid-base environment. Anthocyanin will change from purple to red when it meets acidic substances, which is the key to the beautiful red color of rouge lotus root.
2. Physical properties of ingredients: In the process of blanching and soaking food, attention should be paid to temperature and time to avoid lotus root overheating and softening or insufficient pigment penetration. Proper heat and time can keep the lotus root crisp and tender, and at the same time make the pigment evenly penetrate into the lotus root slices.