抄録
The non-Newtonian behavior and dynamic viscoelasticity of deacylated xanthan solution were measured with a rheogoniometer. The flow curves for the deacylated xanthan at concentrations below 0.5% approximated to shear-thinning behavior, and to plastic behavior above 0.8%. The apparent viscosity of a 0.5% solution of deacylated xanthan increased with increasing temperature up to 25°C, which was estimated to be a transition temperature, then it decreased rapidly. The dynamic modulus of deacylated xanthan increased a little with increase of temperature up to 25 and 30°C in 0.8 and 1.0% solutions, then it decreased rapidly with further increases of temperature. The specific rotation of deacylated xanthan stayed constant up to 25°C, then it decreased rapidly with further increases in temperature. Possible mode of intramolecular associations between an alternate hydroxyl group at C-3 and the adjacent hemiacetal oxygen atom of the D-glucosyl residues, and between the methyl group of the acetyl residue and the adjacent hemiacetal oxygen atom of the D-glucosyl residue were proposed.
