THE BALANCE OF ACID-FORMING AND BASE-FORMING ELEMENTS IN FOODS, AND ITS RELATION TO AMMONIA METABOLISM

Abstract

In recent years the ash constituents of foods have come to hold an increasingly prominent place in considerations of food values.It is now generally recognized not only that.thefood as a whole should supply adequate amounts of each of the chemical'elements which is essential to the body structure, but also that these elements should stand in normal quantitative relations to each other.Conspicuous among the quantitative relations is that between the acid-forming and the base-forming elements of the food.It has long been known that certain foods contain a surplus of baseforming over acid-forming elements as evidenced by the fact that on burning they yield a strongly alkaline ash, whereas other foods lose acid-forming elements in ashing and yet yield a neutral ash showing that acid-forming elements must have predominated in the food.It was, however, not possible to make any useful quantitative comparisons on the basis of the data which had been obtained by the usual methods and recorded in the accepted tables of ash analyses, because these data represented only the compcsition of the material which remained after ignition, regardless of the fact that in many cases a large part of the acid-forming elements exist in the food as constituents of the organic matter and pass off during the ignition.This is particularly true of sulphur, which, so far as known, exists in foods chiefly as a constituent of protein and often is expelled almost entirely during the burning,