Gelation and Structural Formation of Amylose by In Situ Neutralization as Observed by Small-Angle X-ray Scattering

The gelation and structural formation of two types of amylose in alkaline solution by in situ neutralization was monitored with time-resolved small-angle X-ray scattering (tr-SAXS). Sharp increases of SAXS profile in lower angle region were observed after gelation. The results showed that aggregation of amylose chains led to a gel point with crystal growth. The aggregation appeared to function as a junction zone, and the aggregate structure depended on the molecular weight of amylose. A high-molecular-weight sample was fitted using a Debye-Bueche function, and a low-molecular-weight sample was fitted using a stretched exponential function.