Abstract:[Objective] This study aims to characterize the structure and investigate the solution properties of oat β-glucan (OBG). [Method] Two soluble OBGs with different weigh-average molecular weights (Mw), number-average molar weights (Mn), and peak molecular weights (Mp) were prepared by hot water extraction and ethanol classification. The structures and solution properties were characterized by Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), scanning electron microscopy (SEM), high performance size exclusion chromatography coupled with multi-angle laser light scattering (HPSEC-MALLS), and rheology. [Result] OBG-1 and OBG-2 showed the Mw of 80.73×104 g/mol and 8.05×104 g/mol, the yields of (4.86±0.55)% and (3.32±0.31)%, and the purity of (94.21±0.17)% and (90.43±0.34)%, respectively. Both OBG-1 and OBG-2 were fibrous glucans composed of β-D-glucopyranose molecules linked by β-(1,3)-glycosidic and β-(1,4)-glycosidic bonds. OBG-1 contained more cellotriose and cellotetrose and had a smoother surface than OBG-2. In the aqueous solution, OBG-1 exhibited high viscosity and gel properties. [Conclusion] The method combining multiple instruments to characterize the structure and solution properties of OBG is more reliable than single characterization methods, providing a reference for the research on the activity and physiological functions of OBG.
