Synergistic Interaction Between Deacylated Xanthan and Galactomannan

ABSTRACT

The dynamic modulus and optical rotation of a mixed solution of denatured xanthan (depyruvated and deacylated) and galactomannan (locust-bean gum and guar gum) were measured with a rheogoniometer and a polarimeter. Gelation occurred in a mixture of native xanthan with locust-bean gum at a concentration of 0.2% total gums at room temperature, but not with guar gum. A mixture of deacylated xanthan and locust-bean gum showed the highest dynamic modulus, about three times as strong ast that of a mixture with depyruvated xanthan. The dynamic modulus of a mixture of deacylated xanthan and locust-bean gum stayed at very small value in the presence of CaCl₂ (6.8 mM) and urea (4.0 M). Possible binding sites between deacylated xanthan and locust-bean gum molecules are proposed.