The effect of increasing acidity on the solubility of calcium, magnesium and phosphorus in certain cereals and pure salts

Abstract

1. The solubilities of calcium, magnesium and phosphorus in bran, wheat, oats and certain mineral supplements have been determined at pH values between 6·5 and 1·0.2. The solubility of calcium in calcium carbonate varied with the cereal present, but it was always completely soluble at pH 3·0 and below.3. The calcium present in bran and wheat was not readily soluble; that in oats was fairly readily soluble.4. Magnesium dissolved more readily at higher pH values than calcium.5. Phosphorus in bran (with or without added calcium), and that present as pure salts, was almost completely dissolved at pH 3·0 and below, but very low phosphorus solubilities were found at these pH values in oats and, to a lesser extent, wheat.6. These results have been considered in relation to the acidification of food which occurs in the true stomach.