Molecular Weights of Konjac Mannans of Various Sources

By light scattering method, the molecular weights and the radii of gyration of konjac mannans from various sources have been studied. The results are: (1) The molecule of konjac mannan suffered degradation into almost one-fourth by acetylation or by the traditional preparation of konjac flour. (2) The differences in rheological properties of the rigid gels from different strains could be interpreted in terms of the light scattering measurements. (3) The peculiar properties of the Shina-shu have been explained by its Zimm plot behavior at the part of low angle. (4) The distinct differences have been observed in the values of Mw and RG of the same strains porduced from different areas. Good pararellism has been found between the traditional “Mizuhiki-test” and the results of light scattering measurements.