A method for the estimation of the salt content from the pH value of apple juice, and some comparative analyses of the mineral content of the juice and whole apple

Abstract

By measuring the PH and titratable acidity of apple juice and comparing with the acidity and pH of known mixtures of malic acid and K-malate it is possible to obtain a quite accurate estimation of the salt content of the juice. The same % of potash was found in the expressed juice as in the whole apple. Larger % of magnesia and lime is found in the juice than in the whole apple, from which it is concluded that the juice has dissolved lime and magnesia from the cell wall. Half-apples showed in storage a decrease in acidity and specific gravity. The % of phosphate and magnesia in the juice is less, probably due to a decrease in the solvent action of the less acid juice.