edible.

The potato blackening is not caused by the oxidation of starch, but by the oxidation of phenols in the potato. When potatoes are peeled, phenols in plant cells are oxidized by phenolase in the air to produce a large number of quinones. Newborn quinones can quickly brown plant cells, which is called enzymatic browning of food.

So apples will change color after peeling for a period of time. Not only potatoes, but also some vegetables. This browning will affect the appearance of food and reduce the nutrients in the outer layer, but it is edible.

Extended information

When potatoes are peeled and left for a long time, the oxidative decomposition of plant cells in the air is intensified, so the nutrients in the outer layer of potatoes are decomposed more, and pectin substances are further decomposed into pectin acid and methanol under the action of enzymes, which makes the pulp loose, moist, discolored, stale and even rotten. Therefore, it is best to eat it immediately after peeling.

A simple way to control the discoloration of potatoes is to immediately soak peeled potatoes in cold boiled water, sugar water or light salt water to isolate them from the air, so as to prevent the oxidation of phenolic substances in plant cells. Or a few drops of vinegar in water can make potatoes white. However, from the perspective of preserving the nutrients in potatoes, peeled potatoes should not be soaked for too long.

reference materials? People's Network-Can potatoes be eaten when they are oxidized and browned? How to prevent potato oxidation