Apply a drop of iodine to the cut of the potato. What happened to the tuber tissue? Why did the slice change color?

When iodine is applied to a cut of potatoes, it will change color to blue-violet, since it contains starch. A characteristic qualitative reaction to starch is its reaction with iodine. The cut of the tuber has changed color, because in potatoes, starch is found in large quantities. Starch is the main storage substance of potato tubers.