Abstract
A theory for exchange of calcium between milk or model milk-protein system and an appropriately buffered weak cation-exchange resin was developed which could be used for determination of protein-bound or colloidal calcium. With suitable preconditioning of the resin, the resin-contact-time method yielded results for ionic and protein-bound calcium in a model β-casein system which not only conformed to the proposed theory but also agreed with those by the murexide method of Sundararajan and Whitney. β-Casein dispersions (3%) in calcium-potassium chloride solutions at pH 7.0, Γ/2 .14, and 2°C bound calcium as if there were 11.20 binding sites per molecule, each with an intrinsic association constant of 76.62 liters per mole. Data from skim milk samples at 23°C and 2°C by the resin-contact-time method also were consistent with the proposed theory and yielded protein-bound or colloidal calcium in reasonable agreement with reported results.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call