摘要：The network structure of β-glucan polymers and the presence of water have significant effects on the properties of β-glucan gels produced by freeze-thaw cycles. The properties of the gel are influenced by its fine structure, molecular size, mass fraction, number of freeze-thaw cycles, and temperature of the β-glucan. To characterize β-glucan freeze-thaw gels, we used low-field nuclear magnetic resonance (LF-NMR) to measure water proton transverse relaxation in aqueous β-glucan solutions during storage. The results indicated that microphase separation occurred during cryogelation, and three water components were identified in the cryostructure. The spin-spin relaxation time was analyzed on the basis of chemical exchange and diffusion exchange theory. The location of each water component was identified in the porous microstructure of the cryogel. The pore size measured from scanning electron microscopy (SEM) images agreed with the pore size estimated from relaxation time. The formation of cryogel was confirmed by rheological. The results suggested that LF-NMR can monitor the polysaccharide cryogelation process by the evolution of spin-spin relaxation characteristics.
关键词：β-glucan; cryogelation; LF-NMR; water distribution; SEM; rheology
