Starch content

Starch content represents the main energy reserve of the tuber and a key quality parameter affecting the technological properties of potatoes. With a high starch concentration, tubers boil down significantly and become mealy, which is optimal for mashed potatoes and baking, whereas low starch content allows the product to maintain its shape in salads and during frying.

This parameter is estimated as a percentage of the fresh tuber weight using physical gravimetric methods, such as specific gravity determination, or laboratory chemical analyses, including the Ewers method. In variety trials, starch content below 13% is considered low, 13% to 25% is medium, and above 25% is high.

The level of starch content is determined by the genetic potential of the variety and its maturity group, where late-maturing varieties usually accumulate more starch than early ones. This parameter is also significantly influenced by growing conditions, including moisture levels, nitrogen nutrition balance, and potassium fertilizer application, as well as temperature conditions during subsequent crop storage.