The effects of boiling and leaching on the content of potassium and other minerals in potatoes

The white potato (Solanum tuberosum L) is a valuable source of potassium in the human diet. While most consumers benefit from high levels of potassium in potato tubers, individuals with compromised kidney function must minimize their potassium intake. This study was undertaken to determine the effects of leaching and boiling on levels of potassium and other minerals in potato tubers. Leaching alone did not significantly reduce levels of potassium or other minerals in tubers. Boiling tuber cubes and shredded tubers decreased potassium levels by 50% and 75%, respectively. Reductions in mineral amounts following boiling were observed for phosphorus, magnesium, sulfur, zinc, manganese, and iron. There was no difference between the leaching and boiling treatment and the boiling treatment. In addition, mineral levels in tubers of 6 North American potato cultivars are reported. Significant differences in mineral levels were detected among cultivars, but they were too small to be nutritionally important. Individuals wishing to maximize the mineral nutrition benefits of consuming potatoes should boil them whole or bake, roast, or microwave them. Those who must reduce potassium uptake should boil small pieces before consuming them.