Changes to the morphology, density and mechanical stiffness of phytoglycogen nanoparticles subjected to acid hydrolysis

Phytoglycogen (PG) is a glucose-based polymer with a dendritic architecture produced as compact nanoparticles in sweet corn. Its deformability, hydration, biocompatibility and digestibility make PG nanoparticles ideal for applications in personal care, nutraceuticals, and drug delivery. The particles can also be modified chemically to tune their physical properties, opening up possibilities for new applications. We performed acid hydrolysis, a process in which glycosidic bonds between the glucose subunits are broken by exposure to heated dilute acid. Dynamic light scattering and rheology measurements have shown that acid hydrolysis produces smaller, less dense particles [1]. We have used size-exclusion chromatography with multi-angle light scattering and atomic force microscopy force spectroscopy [2] to measure the dependence of the radius, molar mass and mechanical stiffness of the particles on hydrolysis time. These measurements allow us to quantify changes to the morphology, average density and the stiffness distribution within the PG particles with acid hydrolysis.

[1] H. Shamana and J.R. Dutcher, Biomacromolecules 23, 2040 (2022).

[2] B. Baylis et al., Biomacromolecules 22, 2985 (2021).