Abstract
Konjac mannan (KM) is a water-soluble glucomannan with high molar mass. Here, the effects of γ-irradiation on the structure of KM, its viscosity, molar mass distribution and the state of sorbed water were studied after irradiation at reduced pressure. These changes were investigated using ESR, FT-IR, UV, viscometer, SEC–MALS and DSC. Free radical yields increased with absorbed dose. Irradiation led to chain scission, but introduced no significant new chemical groups into the structure, apart from a small increase in content of carbonyl groups. The intrinsic viscosity, molar mass and radius of gyration decreased rapidly with increasing dose up to 10 kGy and then at a slower rate. The Mark–Houwink–Sakurada equation for the KM gave [ η]=5.30×10 −4 M 0.78. The α value showed that KM molecules are solvated in the form of random coils in water. There are three types of sorbed water in irradiated KM as in the original KM. There is no significant change in water binding ability for KM with M W greater than 2×10 5.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
