Elution of inorganic elements from various foods by boiling

Abstract

The elution of inorganic elements from various foods into boiling water was compared. Sodium and potassium were most easily eluted, and boiling for 10 min reduced their contents in potatoes and vegetables by 20 %–30 % and of meat by nearly 50 %. Magnesium, calcium, phosphorus, manganese, and copper followed them regarding the easiness of elution during boiling. Meat often had higher elution rates for all elements probably because of tissue contraction and leakage of drips by protein denaturation at heating. The presence of fat and casing of meat tended to suppress element elution from pork. An increase in the food surface area linearly decreased the retention rates of sodium and potassium in radish and tofu. A two-phase decrease was observed for some elements in pork. The addition of alkaline metal cations to the boiling water did not affect the elution of sodium and potassium from radish.