抄録
Xanthan is a double helical polysaccharide which is used as a viscosity enhancer for foods and cosmetics. The helices of xanthan are unwound by heating (denaturation) and rewound by cooling (renaturation) the solution. Circular dichroism spectrum of renatured xanthan was essentially identical to that of native xanthan, which suggests renatured xanthan recovered the original local structure. However, the molar mass distribution and solution viscosity of renatured xanthan were not identical to those of native ones. This discrepancy is explained by that renatured xanthan recovered the local structure (helical structure), but its global structure was changed during the denaturation and renaturation. The changes in the global structure induced by the denaturation and renaturation were investigated mainly by static light scattering, size exclusion chromatography, and intrinsic viscosity measurements.