Abstract
We compared dietary minerals measured directly from food cooked following the therapeutic diet menu for patients with mild renal disease with those calculated from a food table, to estimate the loss of minerals due to cooking. The results obtained were as follows: 1) The percentage of the measured to the calculated values ranged from 62-67% for K and Fe, to 77-81% for Na, P, Mg and Mn, and 90% for Ca. The measured values for Zn and Cu were similar to the calculated values. 2) We also estimated the differences between the measured and calculated values for various cooking methods. More minerals were lost after boiling or soaking in water than following thin slicing or squeezing. The loss of K was largest among the minerals studied. In making therapeutic diets, such as a low K diet, selection of cooking methods to avoid mineral loss is important in addition to selection of low-K foods.
