Cation effects on the viscosity of gum ghatti

Abstract

Abstract Gum ghatti may be readily separated into a water‐soluble fraction and a gel fraction. Although the gel fraction contains a higher proportion of calcium ions this is not the cause of gel formation since electrolytes which displace calcium ions do not dissolve the gel. Single‐salt forms of the gel fraction have very similar properties. Added simple electrolytes produce no specific effects related to calcium ion concentration. Different cations have different affinities for the available anionic sites in the gel and this is apparently the reason for the higher calcium concentration in the gel fraction. The gel structure is destroyed by sodium borohydride which suggests that it results from intermolecular linkages unrelated to the cation.