The oxidation of lettuce will also turn purple and then black. It is suggested that the peeled lettuce be fried as soon as possible to make a dish, or eaten cold, so that the lettuce will not change color, but sometimes, we may accidentally cut one more lettuce. The peeled lettuce will be preserved for a long time and will gradually react with the air, leading to discoloration. Lettuce can be eaten if it hasn't gone bad. You can scrape off the purple part and wash it before eating. If the lettuce has been cut and oxidized and turned red, you might as well soak it in water to wash it, so that some oxidized parts can be washed away, and then marinate it with cold sauce to make lettuce or stew.

If the cut lettuce turns purple and the meat is rotten and stale, you can't continue to eat it.

2 How to prevent lettuce from oxidation Soaking in water can prevent vegetables from oxidation, just like treating potatoes. You can also soak lettuce in water to isolate the contact between lettuce and air, which can effectively prevent lettuce from oxidation. If it has been cut and you don't want to keep it fresh in the refrigerator, you can also scald the lettuce with boiling water or slice it, so that the lettuce will not be oxidized. If you want to keep it for a long time, you can cut the lettuce, blanch it with boiling water, cool it and seal it in the refrigerator, so that the lettuce will not go bad for a day or two.

Is it harmful to eat lettuce skin? It is harmless and edible.

1, as long as you twist the peeled skin from the root to the rough skin, you will see the dividing line between tender skin and rough skin, put your thumb between them, and draw forward with a little force to get tender skin with light green ribbons and vertical stripes. Edible lettuce often refers to this tender skin. Stir-fried tender skin with stick meat, slightly biting, delicious.

2. If the lettuce itself is tender, you can't easily peel off the tender skin and eat the skin with high plant fiber content directly to promote stool discharge.

What are the benefits of eating lettuce skin? 1. Lettuce skin can relieve pain. Lettuce peel has a certain analgesic effect. When peeling lettuce, you will find some white juice flowing out. If it is directly applied to the traumatic wound, it will have a good analgesic effect. Usually boiling its lettuce skin in water can relieve abdominal pain.

2. Lettuce skin can promote milk secretion. Lettuce skin can treat female postpartum hypogalactia, because lettuce skin contains a lot of trace element potassium, which can adjust the balance of water and electrolyte in human body and accelerate the secretion of milk. Eating more at ordinary times can also play the role of diuresis and detumescence, and can play a good role in relieving some people's poor urination and body edema.

3, lettuce skin can protect teeth lettuce skin has a bitter leaf diameter, it can remove the odor in the mouth when eaten raw, can remove a variety of bacteria in the mouth, can also strengthen teeth, reduce the harm of some harmful substances to teeth. Lettuce skin can protect teeth, because it contains a certain amount of fluorine, which has obvious strong effect on dentin.