Abstract
Although neither kappa-carrageenan nor locust-bean gum gelled alone, a mixed aqueous solution of the above gums gave a gel at the concentration of 0.6% total gums in a range of low temperatures. The solution also gelled even at the concentration of 0.4% total gums in the presence of 0.1 % KCl. The maximum dynamic modulus was obtained with a series of the samples composed of kappa-carrageenan and locust-bean gum in the mixing ratios of 1:1 and 3:1 at the concentration of 0.6 and 0.8% total gums at 0°C. The dynamic modulus of a mixed solution of kappa-carrageenan and locust-bean gum was not influenced by pH between pH 7.0 to 11.5, but decreased in the acidic range.
We concluded that intermolecular interactions, at low temperature, between kappacarrageenan and locust-bean gum may take place on the K+ -bridge of the former and the backbone of the latter molecule at low concentrations, but at high concentration of the gums, self-association of kappa-carrageenan molecules might also occurred.
