Principle
Starch is a carbohydrate that is also found in human food. Starch is used, for example, for thickening food, because starch swells in warm water. Starch is only formed by plants and not in human or animal organisms. Therefore, starch-containing products include cereal products and potatoes.
Therefore, starch is also preferentially obtained from potatoes. This is reproduced in the student experiment in which starch is extracted from potatoes. The potato is crushed and starch is extracted. All water-soluble components are removed by extraction with water, so that only the starch that is insoluble in cold water remains.